Prop osal to Prepare the A TLAS Detector

for Hadron Collider Ph ysics

at the LHC

Myron Campb ell, Ja y Chapman, Homer Neal, Jianming Qian

Greg T arl  e, Rudi Th un, and Bing Zhou

with R ese ar ch sta

Rob ert Ball, Edw ard Diehl, Stev en Goldfarb, Suen Hou, Daniel Levin, and Sha wn McKee

R andal l L ab or atory of Physics

University of Michigan

A nn A rb or, MI 48109-120

Con ten ts

1 In tro duction 1

2 The A TLAS Exp erimen t 2

3 Mic higan’s en try in to A TLAS 4

4 The High Energy Ph ysics Program at Mic higan 5

4.1 CDF Ph ysics Analysis .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 5

4.2 D¹ Ph ysics Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5 The Comm unit yW orking in A TLAS 7

5.1 Homer Neal . .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 7

5.2 Ja y Chapman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

5.3 Myron Campb ell ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 8

5.4 Jianming Qian . ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 8

5.5 Gregory T arl  e .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 9

5.6 Rudi Th un.. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 9

5.7 Bing Zhou . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

5.8 Rob ert Ball . .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 10

5.9 Edw ard Diehl .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 10

5.10 Daniel Levin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

5.11 Sha wn McKee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5.12 Stev en Goldfarb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5.13 Suen Hou .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 11

6 Univ ersit y Commitmen t to High Energy Ph ysics 12

6.1 F acilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

6.1.1 Departmen tal Instrumen t Shop .. .. .. .. .. ... .. .. .. .. .. 12

6.1.2 HEP Electronics Design F acilit y. . .. .. .. .. ... .. .. .. .. .. 13

6.2 Departmen tal Computing Supp ort . . . . . . . . . . . . . . . . . . . . . . . . . . 13

6.3 HEP Computing Resources . .. .. ... .. .. .. .. ... .. .. .. .. .. 14

7 Mic higan’s Activities in the A TLAS Collab oration 14

7.1 MDT Cham b er construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

7.2 A TLAS Electronics Dev elopmen ts.. ... .. .. .. .. ... .. .. .. .. .. 15

7.3 MiniD A Q for Cham b er/Electronics Certication . . . . . . . . . . . . . . . . . . 16

7.4 Muon Lev el 2 T rigger Algorithm Dev elopmen t .. .. .. ... .. .. .. .. .. 17

7.5 The Dela yLoc k ed Lo op of the DTMR OC TDC Chip .. ... .. .. .. .. .. 18

7.6 Review of A TLAS Computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

7.6.1 In tro duction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

7.6.2 Observ ations and ndings .. ... .. .. .. .. ... .. .. .. .. .. 19

7.6.3 Recomme ndations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

7.6.4 Arc hitectural and Distributed Data Handling Issues . . . . . . . . . . . . 19

8 Mic higan’s Cham b er Construction Activities 19

8.1 Long Drift T ub e R&D .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 20

8.1.1 T est Station Results . .. .. ... .. .. .. .. ... .. .. .. .. .. 20

8.1.2 Sim ulation Results .. .. .. ... .. .. .. .. ... .. .. .. .. .. 21

8.2 Assem bly Area Dev elopmen t. .. .. ... .. .. .. .. ... .. .. .. .. .. 23

8.3 T ub e Assem bly and T esting . .. . . ... .. .. .. .. ... .. .. .. .. .. 23

8.3.1 T ub e comp onen ts. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 24

8.3.2 T ub e Assem bly and T est Stations . . . . . . . . . . . . . . . . . . . . . . 24

8.3.3 Wiring Pro cedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

8.3.4 T ub e Qualit y Assurance T ests . . . . . . . . . . . . . . . . . . . . . . . . 26

8.4 Cham b er Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

8.4.1 Cham b er Comp onen ts .. .. ... .. .. .. .. ... .. .. .. .. .. 28

8.4.2 Cham b er Assem bly Station and T o oling . .. .. ... .. .. .. .. .. 28

8.4.3 Cham b er Construction Pro cedure . . . . . . . . . . . . . . . . . . . . . . 29

8.4.4 Cham b er Qualit y Con trol T ests .. .. .. .. .. ... .. .. .. .. .. 30

8.5 MDT Deliv ery Milestones .. .. .. ... .. .. .. .. ... .. .. .. .. .. 32

9 Mic higan’s Electronics and Data-Acquisition Activities 32

9.1 Data Flo w Rates Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

9.2 The 10K Channels T est of A TLAS Electronics . . . . . . . . . . . . . . . . . . . 34

9.2.1 The Dev elopmen t Stages and T est Fixtures . . . . . . . . . . . . . . . . . 34

9.2.2 MiniD A Q Dev elopmen ts for 10K T ests .. .. .. ... .. .. .. .. .. 35

10 Mic higan’s Sim ulation Activities 36

10.1 MDT Detector Sim ulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

10.2 Studies of Data Flo w with V erilogHDL .. .. .. .. .. ... .. .. .. .. .. 37

11 Mic higan Plans for A TLAS Computation 39

11.1 Computing Infrastructure at Mic higan .. .. .. .. .. ... .. .. .. .. .. 40

11.1.1 The UoM A TLAS Computation Group . . . . . . . . . . . . . . . . . . . 41

11.2 Initial Areas of In terest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

11.2.1 Global T rigger and Ev en t Selection Database . . . . . . . . . . . . . . . . 41

11.2.2 Muon Geometry Database . . . . . . . . . . . . . . . . . . . . . . . . . . 42

11.2.3 Muon Detector Sim ulation and Ph ysics Studies with Com bined Detector

P erformance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

11.2.4 Collab oratory T ools.. .. .. ... .. .. .. .. ... .. .. .. .. .. 43

11.2.5 Remote Access Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

11.2.6 High P erformance Computing Resources and Metacomputing . . . . . . . 45

11.2.7 Upgrade of Mic higan’s Computing Resources . . . . . . . . . . . . . . . . 45

12 Summary 46

13 Budget Description 47

A TLAS

1 In tro duction

In the Spring of 1997 Univ ersit y of Mic higan Ph ysicists, Rob ert Ball, Myron Campb ell, J.

Chapman, Homer Neal, Jianming Qian, Greg T arl  e, and Andy T omasc h applied for Institutional

mem b ership in the A TLAS collab oration. F ollo wing the pro cedures of the organization, the

A TLAS collab oration accepted Mic higan at their rst opp ortunit y in the fall of 1997. Since

then additional individuals at Mic higan ha v e joined the team: Bing Zhou as a new facult y

mem b er, Ed Diehl as a new researc h scien tist, and Rudi Th un, Dan Levin, and Sha wn McKee

as mem b ers of the Departmen t recen tly attracted to the pro ject. A t presen t the A TLAS group

is comp osed of 7 facult y , 4 researc h scien tists, 3 mec hanical tec hnicians, and an electronics

engineer. Sev eral graduate studen ts are w orking on A TLAS pro jects but will lik ely b e directed

to CDF and D¹ data for thesis w ork at the T ev atron as Run I I b egins.

Discussions with the US A TLAS comm uni t y b egan coinciden t with our application for

mem b ership and Mic higan w as almost imm ediatel y included in the Muon Pro ject planning.

Since then w eha v emo v ed forw ard at a rapid place, signing a Memorandum of Understanding

with US A TLAS, reno v ating our high ba y assem bly area for m uon c ham b er construction, and

assuming a cen tral role in the testing and certication of fron t-end electronics for the m uon

MDT system. This latter pro ject has b een expanded to include data o w sim ulations and

the design of on-c ham b er data concen trators. These ma jor eorts ha v e b een coupled with

the con tin uation at Mic higan of lev el 2 m uon trigger w ork started b y Bing Zhou at Boston

Univ ersit y and b y R&D eorts on measuremen t resolution for straigh t tub es with wires under

gra vitational sag. An asso ciation with the TR T detector of A TLAS has also b egun with our

electronics engineer con tributing the Dela yLoc k Lo op design for the fron t-end time digitizer

of the TR T subsystem. It is no w established that Mic higan will:

 Build © 40,000 tub es (man y of the longest) and assem ble them in to the largest c ham b ers

of the m uon MDT endcap. P erform the needed R&D to establish a viable design for the

6 meter tub es of these c ham b ers.

 Manage and p erform the A TLAS m uon fron t-end design certication. This includes

pro duction of 10K c hannels of the design for c ham b er testing. An adjunct of this w ork is

the dev elopmen t of a windo ws based mini-data acquisition system to pro vide a mo dern

\what y ou see is what y ou get" or wysiwyg test and con trol system.

 Con tribute to the design of the TR T fron t-end digitizer and readout c hip, DTMR OC.

 Rene the lev el 2 trigger algorithms and ev aluate the success of these algorithms with

Mon te Carlo sim ulations.

 Pursue a computing and soft w are role that utilizes the considerable resources in infras-

tructure and p ersonnel at Mic higan. This will include incorp oration of collab oratory to ols

in to A TLAS to facilitate distributed researc h, early connection to the In ternet I I, the es-

tablishmen t of a program to assem ble and certify the sim ulation and trac king co de for

1

the m uon MDT, and p ossible dev elopmen t of general purp ose to ols for ob ject-orien ted

(or ob ject-relational) database handling of information for trigger and ev en t selection.

 Assist A TLAS in a review of its state of readiness for all asp ects of o-line computing.

 Con tin ue in v olv eme n t in the nation wide REU (researc h exp erience for undergraduate

program funded b y the NSF) to pro vide opp ortunities for U.S. studen ts to w ork on LHC

pro jects at CERN, as w ell as to engage in the recen tly added program whic h includes

U.S. high sc ho ol teac hers.

2 The A TLAS Exp erimen t

The great eorts b eing made at CERN on the construction of the Large Hadron Collider

(LHC) at a cen ter of mass energy of 14 T eV and ultimate luminosit yof 10

34

cm

2

s

1

will enable

ph ysicists to explore new fron tiers of particle ph ysics. The LHC will b e a unique facilit y to study

the fundamen tal in teractions among particles and the mec hanism of electro w eak symmetry

breaking m uc h more thoroughly than at existing facilities. The ph ysics runs at the LHC are

exp ected to start in 2005. T o allo w observ ations of the rare ev en ts that distinguish b et w een

comp eting theories, the LHC will op erate at high energy and with v ery high ev en t rates. Sev en

T eV proton bunc hes (eac h con taining 10

11

particles) will collide ev ery 25 ns, and as a result

LHC detectors m ust cop e with an a v erage of 18 sup erimp osed in teractions p er bunc h crossing.

This v ery high ev en t rate p oses a ma jor c hallenge to the design and pro duction of precise

and reliable particle detectors whic hm ust w ork w ell for man yy ears in an en vironmen t with

v ery high radiation dose and particle rates. T o build suc h a particle detector for the LHC, the

A TLAS collab oration w as formed in 1994 [1]. It consists of ph ysicists and engineers from nearly

150 univ ersities and lab oratories from around the w orld. Thirt y of the A TLAS institutions and

ab out 250 of the collab orators are from the United States. Through sev eral y ears of hard

w ork on the detector R&D, the A TLAS detector has b een designed to exploit the full ph ysics

p oten tial of the LHC, and has no wen tered the construction phase.

The A TLAS detector has o v erall length of 42 meters, and diameter of 22 meters. The total

w eigh t is a b out 7000 tons. The main sub-detector comp onen ts of A TLAS are:

1. Sup erconducting magnets:

a) Solenoid: pro vides a 2 T magnetic eld for the inner detectors in a cylinder of length

6.80 m and diameter 2.30 m.

b) Barrel toroid: an air core toroid consisting of eigh t at coils ab out the b eam axis, eac h

of length 25 m, inner diameter 9.4 m and outer diameter 20.1 m. The b ending p o w er for

m uon momen tum measuremen ts is t ypically 3 Tm.

c) Tw o end-cap toroids: eac hha ving eigh t at coils ab out the b eam axis. Eac h end-cap

toroid extends for a length 5 m from the end of the barrel toroid. The end-cap toroids

ha v e inner diameter 1.65 m and outer diameter 10.7 m. They pro vide appro ximately6 Tm b ending p o w er for m uon momen tum measuremen ts in the end-cap region.

2

2. Inner trac king detector: This is con tained within the solenoid, and consists of 140

million Si pixels and 6 million silicon strip detectors near the in teraction p oin t, and 0.4

million stra w-tub e trac king detectors with transition radiation capabilit y in the outer part

of the inner detector.

3. Electromagnetic calorimeters: Liquid argon accordion detectors in the barrel and

end-cap regions (total ab out 180,000 c hannels).

4. Hadronic calorimeters: liquid argon parallel plate detectors in the end-caps ( ¦ 10 ; 000

c hannels), and tile scin tillators ( ¦ 10 ; 000 c hannels) in the barrel region, and liquid argon

tub e electro de forw ard calorimeters extends the co v erage to  =5.

5. Muon sp ectrometer:

a) 1194 precision trac king c ham b ers made of 371488 monitored drift tub es (MDT) co v-

ering the trac king rapidit y(  ) region from  = 2 : 7to  =2 : 7.

b) 32 catho de strip c ham b ers (CSC) consisting of 102,000 wires co v ering the most forw ard

rapidit y region ( j  j =2 : 0{2 : 7) in the inner sup er-la y er of the m uon system.

c) 596 resistiv e plate c ham b ers (RPC) in barrel region ( j  j < 1) and 4256 thin gap

c ham b ers (TGC) in end-cap regions to pro vide m uon triggers and to measure the second

co ordinate of the m uon trac ks.

In tensiv e R&D and tests ha v e sho wn that the A TLAS detector will ha v e excellen t lepton, photon

and hadronic jet iden tication capabilities and accurate energy and angular measuremen ts o v er

almost 4 © co v erage. V ery detailed b enc hmark ph ysics studies using full detector sim ulation

and ev en t reconstruction programs demonstrated that the turn-on of the LHC in 2005 will

op en an enormous windo w for in v estigating the outstanding questions of particle ph ysics using

the A TLAS detector. This windo w promises insigh ts in to the ph ysics of electro w eak symmetry

breaking, though the precise nature of this phenomenon remains unkno wn. Bey ond electro w eak

ph ysics, there are sp eculations on what ma y lie within the LHC energy region. They range

from new, hea vy fermions to extensions of the standard electro w eak gauge group, and ev en

to extended structures asso ciated with electro w eak symmetry breaking. Examples of ph ysics

disco v ery p oten tial of the A TLAS exp erimen t are listed b elo w:

 If the SM Higgs exists and has not b een disco v ered at T ev atron, it will b e disco v ered at

the LHC. The k ey role of the Higgs as the origin of mass will b e explored extensiv ely at

the LHC.

 If a sup ersymmetric mo del of the sub-n uclear w orld represen ts realit y , some manifestation

of sup ersymmetry will b e observ ed: (a) at least one (probably more) SUSY Higgs; (b)

scalar fermion will b e prob ed up to 1-2 T eV mass range.

 Additional gauge b osons ( Z

0

;W

0

)w ould b e seen up to 4-5 T eV.

 T ec hnicolor resonances could b e observ ed up to 1-2 T eV.

 P ossible substructure of the quarks can b e prob ed up to a scale of 20 T eV.

The c haracteristics of the A TLAS detector design dene a sup erb ph ysics program, and ensure

a leading role for A TLAS in the middle of the next decade.

3

3 Mic higan’s en try in to A TLAS

The Univ ersit y of Mic higan w as formally admitted to the collab oration in the F all 1997. Our

initial in v estigations in to the dev elopmen t plans for A TLAS rev ealed that the fabrication of

the largest c ham b ers of the m uon MDT system needed the atten tion of an institution with

exp ertise in precision c ham b er construction. Th us, almost coinciden t with our admission to

the collab oration, m utual agreemen tw as reac hed on a plan to build the largest MDT c ham b ers

at Mic higan. This commitm en t has required Mic higan to establish a large assem bly area for

these c ham b ers and for the asso ciated tub e preparation.

All c ham b ers in the MDT system are to share a common fron t-end readout system. This fron t-

end readout system has a strong US and Japanese commitm e n t with primary resp onsibilit y

for the deliv ery of the Amplier Shap er Discriminator (ASD) and Time to Digital Con v erter

(TDC) fron t-end comp onen ts resting with Boston Univ ersit y , Harv ard Univ ersit y , and KEK

in Japan. Ho w ev er, no institution w as c harged with the in tegration and certication of these

k ey comp onen ts. Mic higan has accepted this role and the accompan ying task of preparation of

10K c hannels of the A TLAS fron t-end design to b e used for c ham b er testing as w ell as design

certication. In conjunction with this role, Mic higan has assumed resp onsibilit y for the c hip

testing and in tegration of the CERN designed m uon TDC, called the AMT-0.1.

Tw o additional areas receiv ed signican t con tributions from Mic higan v ery so on after en try

in to A TLAS. Ov er the past y ear Homer Neal has pla y ed a role in helping US A TLAS dev elop

a plan for meeting its future computing needs, b yc hairing a T ask F orce that iden tied areas of

computing exp ertise within US A TLAS, that recommende d a sp ecial role for LBNL and ANL

in co ordinating US A TLAS computing activities, and that initiated join t planning eort with

US CMS on transatlan tic net w orking issues and on the dev elopmen t of collab oratory to ols.

Also, at the request of the A TLAS Executiv e Board, Homer Neal c haired a ma jor review of

the state of preparedness of the o v erall A TLAS collab oration in oine computing. The w ork

of that committe e led to sev eral recommendations for far-reac hing c hanges designed to insure

that the goal of migration to OO/C++ (ob ject orien ted) programs and databases is ac hiev ed.

A second imm ediate activit yin A TLAS w as participation b y one of our electronics engineers in

the design, sim ulation, and incorp oration of a Dela yLoc k ed Lo op, DLL, design in to the time

digitizer of the TR T fron t-end circuitry .

Mic higan’s broad exp erience in the eld of high energy ph ysics and the signican t institutional

infrastructure it p ossesses will p ermit us to mak e other ma jor con tributions to the A TLAS

detector and to the successful execution of the exp erimen t. As bac kground material, the fol-

lo wing sections con tain a brief summary of the curren t High Energy Ph ysics program at the

Univ ersit y of Mic higan and of the facilities presen t in the departmen t that will b e applied to

A TLAS detector dev elopmen t, fabrication, and testing. T o further supp ort our request, w e

ha v e included a brief summary of the bac kground of the individuals who ha v e committe dto

A TLAS, outlining brie y their particular areas of exp ertise.

4

4 The High Energy Ph ysics Program at Mic higan

The High Energy Comm unit y is large at Mic higan. In all there are 34 F acult y/Researc h Scien-

tists, 14 p ost do ctoral fello ws, 5 engineering/tec hnical sta, 15 graduate studen ts, 5 adminis-

trativ e/secretarial sta, and n umerous undergraduates w orking in HEP and related elds. The

researc h spans most areas of HEP including hadron and electron collider exp erimen ts, hadron

and electron xed target exp erimen ts, and particle astro-ph ysics exp erimen ts. The w ork is par-

titioned in 10 distinct exp erimen tal activities and a div erse theory comm unit y . Some F acult y

w ork on a single exp erimen t, others participate in m ultiple exp erimen ts. The ric h div ersit y

oers individuals the opp ortunities for c hoice and the c hallenge to learn the science of man y

HEP areas. Sp ecically , for graduate studen ts there are c hoices. The full comm uni t y in HEP

totals nearly 100 p eople. Our seminars in HEP are w ell attended and liv ely .

The t w o Mic higan HEP activities most closely related to the ph ysics of A TLAS are the CDF

and D¹ exp erimen ts. Since man y of the ph ysicists participating in A TLAS are also mem b ers

of the CDF or D¹ comm uniti es where the o v erlap of ph ysics with A TLAS is clear, the sp ecic

ph ysics analysis of CDF and D¹ are summarized b elo w.

4.1 CDF Ph ysics Analysis

The CDF group at the Univ ersit y of Mic higan has four facult y mem b ers: Dan Amidei, Myron

Campb ell, J. Chapman, and Da vid Gerdes. The searc h for and disco v ery of the top quark

has b een the cen tral theme in Mic higan’s CDF analysis eorts. A ma jor comp onen t of this

eort w as the dev elopmen t of algorithms for nding and measuring secondary v ertices since

top quark deca ys include displaced b deca yv ertices. The group also pla y ed a ma jor role in the

construction, commissioning, and op eration of the CDF detector for Run I and con tin ues to do

so for Run I I.

The top quark mass measuremen t in the lepton plus jets mo de w as the sub ject of Nathan

Eddy’s thesis. Nathan w as instrumen tal in the determination of the energy calibration functions

used in the top quark mass determination. Nathan is no w a p ostdo ctoral fello w at the Univ ersit y

of Illinois. Kevin Burk ett analyzed CDF Run I data for measuremen t of the B

s

lifetime. He is

no w at Harv ard Univ ersit y .

Graduate studen tDa vid Winn has, as his thesis topic, made a measuremen t of the W

Helicit yF ractions in T op Deca y . He has dev elop ed a tec hnique that uses the shap e of the

lepton P

T

sp ectrum in the lab frame to measure the comp osition of W helicities in the top rest

frame. This is a tec hnique that should b e directly applicable to analysis of A TLAS data.

Mo dels for the lepton P

T

distribution exp ected from eac h of the W helicities w ere dev elop ed

using a custom v ersion of HER WIG created b y Gene Guillian. Gene did this w ork as part of histhesis on the T op Quark Deca y Kinematics in F ully Reconstructed Lepton + Jets Ev en ts. The

basic thrust of this w ork is to examine the c harged lepton energy and angular distribution in

the rest frame of the leptonically deca ying top quark, and compare the data to the prediction

of the standard mo del. According to the standard mo del, the top quarks should b e pro duced

in p  p ! t



t with top quark spin unp olarized, and the c harged lepton should ha v e an isotropic

5

angular distribution. If, ho w ev er, a large degree of anomalous p olarization is presen t, then

the angular distribution should b e highly asymmetric . The data sho w some suggestiv e large

p olarizations, but a factor of 20 larger sample size is necessary to mak e this an in teresting

measuremen t.

Da vid W olinski is dev eloping a tec hnique for c harm tagging to b e applied to data in his

thesis. He will emplo y this tec hnique to searc h for F CNC top deca ys in Run I data. Sarah

T ruitt is searc hing for single top pro duction. Single top has not y et b een observ ed. The

exp ectation is that her thesis will b oth dev elop the tec hnique for searc hing in next runs data

and will set a limit from the curren t data. All of these topics will b e in teresting at A TLAS as

w ell. The CDF group has a pro v en trac k record for dev eloping the to ols and tec hniques needed

in these analyses.

4.2 D¹ Ph ysics Analyses

The Univ ersit y of Mic higan D¹ group presen tly consists of three facult y: Neal, Qian and

Zhou. The top quark ph ysics and searc hes for new phenomena ha v e b een our main ph ysics-

analyses activities with data collected during the 1992{1996 T ev atron run. W eha v e made

ma jor con tributions to b oth ph ysics topics. In fact, w e are sole or signican t con tributors to

ab out 10% of the D¹ ph ysics publications. The Mic higan D¹ group also designed, fabricated,

and installed the In ter Cry ostat Detector (ICD) for Run I and has designed and deliv ered the

Pre-Sho w er detector for Run I I.

One of our graduate studen ts Sailesh Chopra w as resp onsible for the t



t ! e + jets analysis at the

time of the top quark disco v ery .A t that time, the c hannel had v e candidate ev en ts with 1.2

ev en ts exp ected from bac kground pro cesses and con tributed signican tly to the o v erall excess

of candidate ev en ts. Another studen tF rank Hsieh w as resp onsible for the jet energy calibration

for the top quark cross section and mass analyses. The calibration w as done using the w ell

measured photon energies b y exploring the transv erse energy balance exp ected in + jets ev en ts.

His w ork led to a 2.5% measuremen t in jet energy and thereb y reduced the systematic error on

the measured top quark mass signican tly . Hsieh also carried out an indep enden t top quark

mass determination.

Researc h fello w Donald Stew art and Assistan t Researc h Scien tist Norm Amos led the D¹

t



t ! alljet w orking group for m uc h of its existence. This analysis w as particularly c hallenging.

Though the nal state accoun ts for 44% of all t



t deca ys in the Standard Mo del, the QCD

m ultijet bac kground o v erwhelms the signal b y a ratio of 2000 to 1. Man y simple and complex

approac hes w ere tried. In the end, a m ultiv ariate tec hnique using a neural net w ork w as used

to extract the t



t signal b ecause it yielded the b est signal to bac kground ratio. In fact, the t



t

pro duction cross section determined in this c hannel represen ts the single b est measuremen tin

D¹.

In the area of new phenomena searc hes, Chopra carried out searc hes for diphoton ev en ts with

large transv erse momen tum im balance ( / E

T

), and single photon ev en ts with jets and large / E

T

.

These searc hes w ere motiv ated b y suggestions that sup ersymmetry ma y result in signatures

in v olving one or more photons. Unfortunately , no excess w as observ ed b ey ond exp ectation in

6

either single and diphoton ev en ts. Tigh t constrain ts on new ph ysics mo dels w ere deriv ed and

some theoretical sp eculations w ere excluded.

F or the next T ev atron run b eginning in y ear 2000, our ph ysics in terests lie in the areas of top

quark ph ysics and searc hes for the Higgs b oson and new-ph ysics signatures. In the top quark

ph ysics, w e are in terested in studying the branc hing ratios of the top quark deca ys. F or the

Higgs searc h, w e plan to study the inclusiv e Wb



b ev en ts, exp ected from the most promising

mo de p  p ! WH ( ! b



b ) for Higgs of mass is less than 130 GeV as w ell as for other non-

Higgs Standard Mo del pro cesses. F or a higher mass Higgs, our Researc hF ello w Andre T urcot

(together with T. Han, R.-J. Zhang of Wisconsin) demonstrated recen tly that the T ev atron will

b e the rst accelerator capable of probing the Higgs sectors near the WW threshold. F or new

phenomena searc hes, w e are in terested in leptonic and photonic nal states in general.

5 The Comm unit yW orking in A TLAS

The A TLAS group at Mic higan comes mostly from the hadron collider comm uni ties with exp e-

rience in the CDF and D¹ exp erimen ts. The list includes Homer Neal, Ja y Chapman, Myron

Campb ell, Jianming Qian, Rudi Th un, and Bing Zhou. Gregory T arl e, Ed Diehl, Dan Levin,

Sha wn Mc k ee, and Rob ert Ball bring their exp erience with precision trac king and data acqui-

sition from ballo on exp erimen ts and L3 resp ectiv ely .

5.1 Homer Neal

Homer has serv ed as the group leader of the Mic higan D¹ task since its inception in 1987.

His p ersonal exp ertise is in detector tec hnology , database design, and computation. His group

assumed the primary resp onsibilit y for the successful design, construction and commissioning of

the D¹ In tercry ostat Detector. He has serv ed as Chair of the Mic higan Departmen tof Ph ysics,

as Vice Presiden t for Researc h and as In terim Presiden t of the Univ ersit y .Ov er the past y ear

he c haired a review committee for A TLAS computing, pla y ed a lead role in the establishmen t

of a Mic higan A TLAS group, serv ed as the UM Institutional Represen tativ ein A TLAS, and

completed the analysis of a proton-proton scattering mo del he adv anced to explain large spin

eects at high energies. In addition, he has serv ed as a co-PI (with a US CMS colleague)

on a gran t whic h has established a NSF \Researc h Exp erience for Undergraduates" site at

CERN, making it p ossible for US undergraduates to sp end a summer at CERN w orking on

LHC pro jects. He has also b een in v olv ed with collab oratory R/D eorts and in eorts to

facilitate CERN joining the In ternet I I consortium, a step that w ould enhance the net w ork

bandwidth b et w een Mic higan and CERN. It is Homer Neal’s exp ectation that he w ould dev ote

at least 80% of his researc h eort to A TLAS o v er the next v ey ears.

7

5.2 Ja y Chapman

Ja y is curren tly w orking in CDF and has resp onsibilit y for the lev el 1 m uon trigger circuitry for

Run 2 whic h includes 2 custom VLSI designs and n umerous b oard designs for the dev elopmen t

of the lev el 1 trigger primitiv e s. These trigger primitiv e s are electronically correlated in a second

unit that asso ciates m uon hits with trac ks from the cen tral trac k er. This latter unit is also the

resp onsibilit y of the Mic higan group. Another ma jor con tribution has b een the design of the

custom TDC c hips for all CDF timing measuremen ts. This w ork w as a join t eort b yJa y ,

Myron, and the engineering sta at Mic higan. Ja y has dev oted ab out 50% of his researc h time

to A TLAS during the past y ear. He has accepted the task of co ordination of the m uon fron t-

end electronics design certication and the pro duction of 10K c hannels of the A TLAS design

for c ham b er testing. His A TLAS p ercen tage will dip during the CDF upgrade commissioning

and return to 50% within 2 y ears. It is hop ed that arrangemen ts can b e made for residency at

CERN during the installation and commissioning of the A TLAS detector. While at CERN the

p ercen tage commitm e n tto A TLAS w ould b e at least 80%.

5.3 Myron Campb ell

Myron is curren tly w orking in CDF with resp onsibilit y for the trac king TDC design, the

calorimeter lev el 2 trigger, and the Lev el 2 pro cessor design. Ab out 500 of the Mic higan

designed 96 c hannel TDCs will b e fabricated. The lev el 2 calorimeter trigger cards p erform jet

clustering and form the energy sums needed for total energy and transv erse energy triggers.

The Lev el 2 trigger pro cessors are based on the Digital Alpha 21164 c hip set and are congured

on 9U VME cards. The lev el 2 trigger system, the hardw are describ ed ab o v e, plus the soft w are

needed to load, con trol, and run the trigger system is a crucial part of CDF and m ust b e in

place b efore the b eginning of the next run. Because of this ma jor commitm en t, Myron exp ects

to dev ote only 10% of his researc h time to A TLAS during the coming t w oy ears, ramping up

to 50% with 3 to 4 y ears. His primary A TLAS role has b een to serv e on the trigger/data

acquisition review committe e.

5.4 Jianming Qian

Jianming Qian is curren tly w orking on the D¹ exp erimen t with resp onsibilities for Run I

ph ysics analyses, Run I I ph ysics studies, and the construction, commissioning and op eration of

the cen tral presho w er detector of the D¹ upgrade. He is presen tly serving as one of the Run I

ph ysics con v eners and is also co ordinating Run I I ph ysics studies in the area of new phenomena

searc h. He exp ects to dev ote ab out 15% of his researc h time to A TLAS in the next few y ears

and to ramp up gradually b efore the LHC turns on.

8

5.5 Gregory T arl  e

Greg is w orking in the HEA T ballo on exp erimen t for the detection of an ti-particles in cosmic-

ra ys. In this exp erimen t Greg’s group w as resp onsible for the mec hanical in tegration of the

pa yload and the magnetic sp ectrometer including the design of the sup erconducting magnet

and the precision drift tub e trac k er. Greg is w orking on the MA CR O exp erimen t where he w as

resp onsible for pro ducing 600 tones of liquid scin tillator, the ERP trigger, and the ADC/TDC

readout. He curren tly sp ends ab out 50% of his time on HEA T, 40% on A TLAS and 10% on

MA CR O. As MA CR O winds do wn he exp ects to shift to appro ximately 50% on HEA T and

50% on A TLAS.

5.6 Rudi Th un

Rudi in tends to dev ote at least 50% of his o v erall researc h eort to the A TLAS exp erimen t. His

main resp onsibilit y will b e the sup ervision of m uon drift-tub e pro duction at Mic higan. During

the past y ear, he has con tributed to measuremen ts of some k ey parameters that c haracterize

these tub es: gra vitational wire sag, electrostatic wire de ection, resp onse to vibrations. The

remainder of Rudi’s researc h eort for the next few y ears ma y b e dev oted to participation in a

CERN-based neutrino oscillation exp erimen t (I216) p ending the outcome of decisions b y CERN

managemen t regarding the I216 prop osal. This situation should b e claried b efore the end of

1999. Rudi’s main areas of exp ertise consist of particle detector design, construction, testing,

and op eration.

5.7 Bing Zhou

Bing joined the UM facult y last summer and has tak en a ma jor resp onsibilit y of constructing

the large precision A TLAS m uon detectors. In the past nearly ten y ears, Bing has activ ely

participated in trac k detector design and dev elopmen t researc h (particularly , drift tub e detec-

tors) for the SSC (GEM) and LHC (A TLAS) exp erimen ts. She w as one of the leading p ersons

who strongly pushed to use the pressurized drift tub e tec hnology for m uon detection at the

SSC. This tec hnology has b een c hosen b y the A TLAS collab oration for constructing the m uon

detector at the LHC. She has pla y ed a leading role in the detector p erformance sim ulations

and ph ysics studies for the A TLAS Muon Detector T ec hnical Design in 1997. During the past

y ear, Bing has concen trated on the construction of the UM A TLAS m uon detector pro duction

stations b oth for tub e and c ham b er assem bly . The tub e assem bly station construction is no w

nearly nished, whic h is almost four mon ths earlier than the original A TLAS UM milestone

sc hedule. The large c ham b er assem bly station construction is underw a y , and the commissioning

of the c ham b er pro duction is exp ected in F all of this y ear.

Before Bing joined the UM facult y , she w as a facult y mem b er at Boston Univ ersit y , where she

led the BU L3 group constructing and commissioning the L3 silicon radiation detector and as-

so ciated LEP b eam dump trigger systems for the L3 silicon micro-v ertex detector. The detector

w as installed in L3 in 1993, and has functioned v ery w ell since then. Bing and her studen ts

also dev oted substan tial eort to the L3 data analysis for precision R

b

measuremen t and for the

9

Higgs searc hes. Recen tly , Bing joined the UM D¹ group and has tak en the resp onsibilit yof

the on-line D A Q system for the pre-sho w er detector whic h is one of the ma jor detector upgrade

items of the D¹ exp erimen t for the T ev atron Run I I program at F ermilab. Bing exp ect to

dev ote ab out 70% of her researc h time to A TLAS.

5.8 Rob ert Ball

Rob ert Ball is curren tly w orking on the F ermilab Mini-Bo oNE and A TLAS exp erimen ts. His

resp onsibilities include the design and realization of the 10K certication-test data-acquisition

system for A TLAS. The UNID A Q data acquisition soft w are whic h he dev elop ed for the SDC

exp erimen t in co op eration with LBL, KEK and the SSCL is still in use in b oth the US and

Japan. P ast w ork on the L3 exp erimen t at CERN included building and op erating a cosmic ra y

test stand for hadron calorimeter wire c ham b er certication and pro duction and op eration of a

F ermilab A CP/R3000 parallel computer system for generation of L3 Mon te Carlo sim ulations.

Rob ert exp ects to a v erage 50% of his time on A TLAS o v er the next 5 y ears.

5.9 Edw ard Diehl

Edw ard Diehl w orks full time on A TLAS. He is resp onsible for o v erseeing the dev elopmen tof

the c ham b er assem bly ro om, as w ell as assisting in a v ariet y of other dev elopmen t jobs for

A TLAS. F or example, setting up an x-ra y surv eying system for A TLAS drift tub es. He has

also w ork ed facilitating the tec hnology transfer in MDT assem bly and testing tec hniques from

other institutes to help Mic higan quic kly dev elop its program. He also writes the mon thly

tec hnical and nancial rep orts on Mic higan’s MDT hardw are w ork. As the pro ject mo v es to a

pro duction phase Ed plans to join in the sim ulation and data analysis eorts. Ed has extensiv e

prior exp erience in b oth hardw are and soft w are. In his thesis on the MA CR O exp erimen t, under

Professor Greg T arl  e at Mic higan, he w ork ed on liquid scin tillator fabrication, electronics, and

analysis soft w are. After this he w ork ed at the Univ ersit y of Chicago on the RICH (Ring-imaging



Cerenk o v) exp erimen t, participating in the full scop e of the pro ject from hardw are dev elopmen t

to data analysis.

5.10 Daniel Levin

Dan has un til recen tly b een activ e i n the TOSCA short baseline neutrino eort. He has curren tly

joined the Univ ersit y of Mic higan A TLAS eort and is engaged in a detailed analysis of end-cap

large c ham b er p erformance p ertaining to trac king and momen tum resolution. He is assuming

resp onsibilit y for c ham b er qualit y assurance and con trol tasks and will set up a facilit y for

nal c ham b er commissioning. Soft w are activities will include w ork on A TLAS soft w are and

sim ulations, particularly with resp ect to Lev el 2 trigger design, ph ysics analysis and database

dev elopmen t. During the past y ear, Dan has con tributed ab out 90% of his time to TOSCA

and A TLAS, and 10% to MA CR O. In the latter he has con tin ued to b e activ e in the sup erno v a

neutrino burst monitoring. As the w ork ev olv es to w ards CERN he w ould lik e to arrange to

b ecome residen t there.

10

5.11 Sha wn McKee

Sha wn is in v olv ed in three dieren t exp erimen ts: A TLAS, t w o-thirds time, and A CCESS (Ad-

v anced Cosmic-ra y Comp osition Exp erimen t for the Space Station) and HEA T (High Energy

An timatter T elescop e) for the remaining one-third. On A CCESS he is helping to organize the

sim ulations of v ery thin, hadronic calorimeter designs for energies up to 1 P eV. His HEA T

eort is dev oted to testing, up dating and debugging the igh t soft w are and D A Q for the next

ballo on igh t in spring of 1999. Sha wn is the soft w are manager and co ordinator for the Mic hi-

gan A TLAS eort. He has had signican t prior ph ysics soft w are exp erience as an SSC F ello w

on the GEM exp erimen t where he w as c hairman of the cen tral trac king sim ulations eort and

on COSMOS (FNAL E803) where he sp earheaded the detector, b eam and ph ysics sim ulations.

His A TLAS w ork is fo cused on dev eloping and main taining the online soft w are for m uon drift

c ham b er construction and testing. In addition, Sha wn will b e participating in the A TLAS wide-

sim ulation eort: dev eloping soft w are to ols and databases, sim ulating detector p erformance and

studying m uon-related A TLAS ev en t sim ulations.

5.12 Stev en Goldfarb

Stev en Goldfarb is curren tly w orking on the Detector Description Database for the A TLAS

Muon Sp ectrometer. This in v olv es the dev elopmen t of C++ ob jects to b e placed in the main

Detector Database. Creating a generic description of the geometry mak es it p ossible for the

new GEANT4 sim ulation and AR VE reconstruction soft w are to use the same detector param-

eters, or subsets of parameters, hence a v oiding the p ossibilit yofam biguit y and allo wing for

the sharing of geometry classes and metho ds. This w ork is on the critical path for all future

soft w are relying on precise sim ulation and reconstruction of m uons in the A TLAS detector.

In addition, Stev e has b een dev oting appro ximately 25% of his time, since joining A TLAS in

June 1998, on the organization of a join tA TLAS/CMS collab oratory to ol R/D initiativ e. This

initiativ e, whic hin v olv es participation of the Univ ersit y of Mic higan Sc ho ol of Information,

Caltec h, UCAID/In ternet 2, the CERN W eb Oce and UM/A TLAS, will dev elop to ols to al-

lo w for greatly impro v ed, seamless comm unication and virtual in teraction b et w een CERN and

participating outside institutes, suc h as the Univ ersit y of Mic higan. Stev e’s other resp onsi-

bilities ha v e included participation in the recen tA TLAS Computing Review Committee , and

the pro duction of a join tA TLAS/CMS do cumen t on the future computing needs of the LHC

[2]. Ov er the next y ear Stev e will commit time to in v estigating the use of the CMS CRIST AL

pro duction database for use with the A TLAS MDT c ham b ers b eing constructed at Mic higan

and will b egin OO soft w are dev elopmen t as part of the Mic higan m uon com bined-p erformance

soft w are activit y .

5.13 Suen Hou

Suen has v ery extensiv e exp erience with trac king detectors and colliding b eam ph ysics analysis

acquired from the researc h programs at LEP (OP AL and L3) and from the SSC R&D w ork.

He joined the UM A TLAS/D0 team in Spring of 1999. He has tak en resp onsibilit y for the

o v erall online system for b oth A TLAS tub e and c ham b er construction at Mic higan. He is also

11

resp onsible for the laser alignmen t and x-ra y imaging device in terfaces and the accompan ying

analysis soft w are. He will also w ork on the D0 online D A Q system for pre-sho w er detectors and

ph ysics analysis as w ell. Suen exp ects to sp end at least 60% of his time on A TLAS c ham ber

construction and testing in the rst 3 y ears, and to ramp up gradually to 100% b efore the LHC

starting the ph ysics run.

6 Univ ersit y Commitmen t to High Energy Ph ysics

It is clear from the size of the High Energy Ph ysics activit y at Mic higan that the Univ ersit y and

Departmen tha v e a con tin uing commitm en t to the eld. The con tin uing nature of this com-

mitmen t is demonstrated b y the recen t app oin tmen ts in High Energy Ph ysics. In the last 10

y ears Mic higan has hired Myron Campb ell, Dan Amidei, Keith Riles, Jianming Qian, Timoth y

McKa y ,W olfgang Lorenzon, and Da vid Gerdes as Assistan t Professors in Exp erimen tal High

Energy Ph ysics/AstroPh ysics. Bing Zhou w as also hired as an Asso ciate Professor of Exp er-

imen tal High Energy Ph ysics. Eac h of these individuals has b een supp orted with lab oratory

space and startup funds.

6.1 F aciliti es

Ma jor researc h supp ort has come from the Univ ersit y in the form of a full reno v ation of the

Randall and W est Hall buildings o ccupied b yPh ysics follo w ed b y the addition of a new Ph ysics

lab oratory building, Ph ysics Researc h Lab oratory . This addition pro vides 66,000 sqft. of high

qualit y lab oratory space with a full sp ectrum of built-in services. The lab oratory links Randall

and W est Hall. High Energy Ph ysics o ccupies roughly 2 o ors of the new lab oratory building.

Three large high-ba y assem bly areas are also a v ailable for the fabrication and testing of HEP

detector elemen ts. One of these areas is committe d to the A TLAS MDT assem bly .

In addition to the lab oratory and oce space pro vided b y the Univ ersit y to the HEP comm uni t y ,

there are services common to all researc h that are shared across disciplines. These include

tec hnical services, instrumen t fabrication and computer net w ork supp ort. The Univ ersit yof

Mic higan has close ties to the In ternet I I pro ject and w e exp ect to b e one of the rst institutions

connected to In ternet I I, the prop osed high-p erformance upgrade of the In ternet.

6.1.1 Departmen tal Instrumen t Shop

The Ph ysics Departmen t’s Main Instrumen t Shop is the largest shop of its kind on the Univ ersit y

of Mic higan campus. Is is staed b y three highly qualied mac hinists who ha v eav ariet yof

training and exp ertise using all of the shop mac hines. Besides standard mac hinery found in all

mac hine shops, the Main Instrumen t Shop also has t w o Computerized Numerical Con trol (CNC)

mills, standard w elding and silv er soldering facilities as w ell as high-v acuum w elding capabilities

and b ead blasting. The sta has had man yy ears of exp erience in mac hining materials ranging

from stainless steel to scin tillator. The rst priorit y of the Main Instrumen t Shop is to serv e

12

the Departmen tof Ph ysics, but b ecause of its size and capabilities, the Shop secondarily serv es

other departmen ts, other univ ersities, national labs, and on o ccasion has done w ork for NASA.

As part of the reno v ation of Randall Lab oratory , additional space has b een added to the Main

Instrumen t Shop.

6.1.2 HEP Electronics Design F acilit y

High Energy Ph ysics op erates a shared electronics design facilit ya v ailable to all HEP exp eri-

men ts. The shop emplo ys three full time engineers with exp erience in high sp eed pulse designs,

analog designs, and digital circuitry .O v er the last sev eral y ears, these engineers ha v e designed

custom in tegrated circuits and XILINX programs, they ha v e designed and built PC b oards

as w ell as complete systems. The shop also emplo ys a full time administrativ e assistan t. In

addition, t ypically 2-4 studen t engineers hold part-time app oin tmen ts in the shop. This is

particularly eectiv e since these studen ts learn the Men tor Graphics soft w are system as part

of their training in Engineering. The facilit y is a rst-rate circuit dev elopmen t lab oratory that

relies on the exceptional design to ols a v ailable through Electrical Engineering. As a result of

the site-licenses with the Engineering Sc ho ol, Ph ysics has access to Men tor Graphics design

soft w are including silicon compilers, syn thesizers, and sim ulators. The HEP engineers are ex-

p erienced with the Men tor CAD system for prin ted circuit b oard and VLSI design. The facilit y

has 7 HP CAD seats running the Men tor Graphics soft w are. With the aid of this soft w are, the

shop engineers ha v e designed and tested 75+ prin ted circuit b oards and 10+ custom ASICs in

the past 8 y ears. Man y of these PC b oards are large F astbus or 9U VME cards. Designs from

Mic higan’s Electronics F acilit yha v e b een selected 3 times b y Men tor Graphics for their Ann ual

T ec hnology Aw ard. The electronics shop has pro vided designs for CDF, Auger, A TLAS, Macro,

SDC, L3, COSMOS, and D¹. W ean ticipate con tin ued leadership in electronics design. The

electronics shop main tains VxW orks and LabWindo ws/CVI based data acquisition computers

and in terface equipmen t as needed for testing new b oards. The facilit yo wns an in tegrated

circuit tester, t w o logic analyzers, n umerous oscilloscop es, VXI instrumen tation, and a comple-

men t of other test devices. A surface moun t pic k and place mac hine and o v en are also a v ailable

in the shop.

6.2 Departmen tal Computing Supp ort

The Departmen tof Ph ysics pro vides computer supp ort through its Oce of Computer Services.

The sta of this unit supp orts that p ortion of the computing activit y whic h is common to the

en tire Departmen t. This includes net w ork connectivit y within and outside the Departmen t,

electronic mail, distributed prin tserv ers, and departmen tal administrativ e computing. Net-

w ork connectivit y to systems outside the Univ ersit y of Mic higan is exceptional since Mic higan

main tains the highest sp eed connections a v ailable to the In ternet.

In addition, the Univ ersit y of Mic higan is a ma jor participating institution in the NSF-

sp onsored National P artnership for Adv anced Computational Infrastructure (NP A CI), and will

pro vide access to, and consultation for, its compute-in tensiv e and data-in tensiv e facilities that

are part of the NP A CI initiativ e at Mic higan.

13

6.3 HEP Computing Resources

Computing within HEP has ev olv ed to a sc heme of w orkstation based distributed clusters. In

this distributed computing mo de, the function of the cen tral service unit is no longer the deliv ery

of computer cycles but the cen tralized supp ort of soft w are, le service, and disk bac kup. All

asp ects of computing other than these are pro vided b y the individual researc h groups. Since the

c hoice of w orkstation platform can b e dieren t for dieren t activities or dieren t purc hase times

(the industry mo v es v ery fast), our cen tral service unit m ust supp ort more than one platform

at a time. A t the presen t time three primary m ultipro cessing platforms are supp orted. They

are HP9000, Digital Alpha, and In tel mac hines running LINUX or Windo wsNT. The com bined

computational and storage capabilit y of these system is 3500 Sp ecMarks of pro cessing capacit y ,

150Gb of disk space, and 8mm, DL T and D A T tap e driv es for data storage and disk bac kup.

In conjunction with this submission is a computer upgrade prop osal to mo dernize the HEP

computing equipmen t. This prop osed upgrade will, if funded, p ermit us to cop e with the

increase in data an ticipated from the CDF and D¹ exp erimen ts and to supp ort the A TLAS

detector dev elopmen t with sim ulation studies.

7 Mic higan’s Activities in the A TLAS Collab oration

Mic higan’s is con tributing to A TLAS in the areas where it has established strengths and also

in areas where mem b ers of the group see imp ortan t future requiremen ts that are not fully

represen ted in the collab oration as a whole. Those areas where w e can immedi ately con tribute

are represen ted b y the building MDT c ham b ers and the electronics instrumen tation of the MDT

and TR T detectors. With a strong bac kground in data acquisition and lev el 2 triggering, w e

exp ect to con tribute to these areas as w ell, fo cusing on the same MDT detector elemen ts. With

resp ect to soft w are and database dev elopmen t, w eha v ein terest in expanding our bac kground

in to the tec hnology of ob ject orien ted analysis co ding and database structure. It is in these

areas w ere w e are anxious to b ecome learners and then leaders b ecause w e b eliev e that only

with these mo dern to ols can individual ph ysicist hop e to comprehend and con trol the complex

and massiv e data from suc h a large exp erimen t. The list b elo win tro duces the topics that

follo w starting with the c ham b er construction and electronics w ork that is w ell underw a y and

ending with more general though ts on ho w Mic higan’s A TLAS team wishes to b e engaged in

computing.

 Cham b er Construction for the Muon MDT Subsystem

 Electronics Dev elopmen t & Data Acquisition in supp ort of the Muon MDT Detector T ests

 Muon Lev el 2 T rigger Algorithm Dev elopmen t

 F ron t-end Electronics Design and T esting for the TR T Subsystem

 A TLAS Computing Issues (Global, US, and Mic higan Plans)

14

7.1 MDT Cham b er construction

The Univ ersit y of Mic higan A TLAS group has tak en resp onsibilit y for the construction of

a substan tial p ortion of the Monitored Drift T ub e (MDT) c ham b ers for the endcap of the

A TLAS m uon system. In the next 5 y ears w e will build ab out 40,000 long precision drift tub es,

and assem ble them in to 104 large m uon c ham b ers: EEL1, EEL2 - the transition sup er la y er

c ham b ers; and EMS4, EMS5, EML3, EML4, EML5 - the middle sup er la y er c ham b ers, 16 eac h,

except EMS4, whic h will b e shared with the U. of W ashington. Our task represen ts ab out 10%

of the total MDT c ham b er construction w ork in the A TLAS m uon system.

The MDT c ham b ers will p erform a precision co ordinate measuremen t in the b ending direc-

tion of the air-core toroidal magnet. The m uon momen tum is determined through a sagitta

measuremen t from three sup er-la y ers of MDT c ham b ers. The total active area of the MDT

c ham b ers in the A TLAS detector is ab out 5500 m

2

, whic h is needed for a go o d momen tum

determination of the m uons with rapidities b et w een -2.7 and +2.7. The trac king resolution p er

tub e is ab out 80 microns. The exp ected resolution for m uon determination is ab out 2.4% for

transv erse momen tum ( P

T

) of 100 GeV.

Mic higan’s tasks for constructing m uon c ham b ers includes detailed mec hanical design, analysis,

man ufacturing, qualit y assurance, qualit y con trol, and testing, of b oth the tub e and c ham ber

assem blies. W e are also resp onsible for shipping and installation of the nished c ham b ers at

CERN. The sp ecial tec hnical c hallenge of our task is to meet the precision requiremen ts o v er

the v ery large scale of the c ham b ers. This requires us to carry out additional R&D w ork

asso ciated with long tub e wire sag issues and large c ham b er assem bly tec hniques. W eha v e

in v estigated these critical issues and ha v e presen ted the results to the A TLAS collab oration. A

brief summary of these presen tations app ears in this prop osal. These results not only eect UM

tub e/c ham b er construction, but also all other A TLAS pro duction sites making large c ham b ers.

In the past y ear, the Mic higan A TLAS group has made great eorts to dev elop and construct

c ham b er pro duction facilities. Details will b e presen ted in sections 8.2 through 8.3 of this

prop osal. W e plan to start the c ham b er mo dule 0 tub e pro duction in middle of Ma y , 1999, and

assem ble the mo dule 0 c ham ber b y the end of 1999. Starting from 2000 w e will pro ceed with

the full c ham b er pro duction un til 2004. F ollo wing c ham b er pro duction, the c ham b ers will b e

shipp ed to CERN for insp ection and installation during 2004-2005 .

7.2 A TLAS Electronics Dev elopmen ts

The A TLAS group at Mic higan has a strong bac kground in electronics design and has naturally

tak en on w ork in this area. Because of our in v olv eme n t with the MDT c ham b er construction,

w eha v e also concen trated our electronics eorts on this subsystem of the detector. The re-

sp onsibilit y for the fron t-end circuit design for the MDT system is geographically distributed

and includes an ASD design at Harv ard and Boston Univ ersities and a TDC design rst done

at CERN with the plan to migrate the design to KEK in Japan. The Mic higan electronics

designers ha v e had previous exp erience at w orking with these individuals in the SSC era and

w ere w armly w elcomed to join the pro ject. One area where a signican t con tribution w as

needed is in the area of co ordination and certication of the design. In the pro ject plan these

15

tasks are called \Readout Arc hitecture" and \T est Fixture" dev elopmen t. There are t w o ma jor

asp ects of this w ork. One in v olv es implem en tation of the A TLAS design at the lev el of 10K

c hannels to pro vide the detector builders with electronics for c ham b er testing. A second goal

is the op eration and certication of the en tire MDT readout design. These t w o asp ects are not

en tirely compatible with the same dev elopmen tsc hedule. There is need to mo v ev ery quic kly

on the pro vision of electronics to the c ham b er builders. Final A TLAS electronics has need for

a more paced sc hedule and, in fact, is b etter serv ed b y p ostp oning fabrication to the latest

date commensurate with on-time deliv ery . Mic higan has tak en resp onsibilit y for the assem bly ,

testing, and programming of the c ham b er testing electronics, certifying the A TLAS design at

the lev el of maturit y consisten t with an early deliv er date for the \test xture".

Mic higan has also accepted resp onsibilit y for complete sp ecication of the nal \readout arc hi-

tecture" along with detailed examination of the p erformance of the design. This w ork b egan

in earnest last summer when Ja yw ork ed at CERN with 3 Mic higan studen ts to review and

quan tify the output of the ph ysics sim ulations in terms that are directly applicable to the elec-

tronic data rates as seen at v arious places along the readout c hain. The a v erage data o ww as

determined and the mo dularit y of the electronics sp ecied. An arrangemen t of trigger to w ers

w as w ork ed out with the lev el 2 trigger sp ecialist. W ork no w con tin ues to complete a sim ula-

tion of the design in the hardw are description language V erilogHDL. This is basically a Mon te

Carlo of electronic data o w whic h generates random input with the statistical c haracteristics

observ ed in the ph ysics Mon te Carlo. The section 9.1 b elo w describ es this w ork in more detail.

7.3 MiniD A Q for Cham b er/Electronics Certication

Mic higan has accepted the task of certifying the design of fron t-end electronics for the MDT

c ham b er sub-system. This is a m ulti-faceted task. Muc h of the nal electronics c hain is not

y et built, nor is it completely designed. F urthermore MDT c ham b ers will roll o pro duction

lines w ell b efore the nal readout system can b e ready ,y et these c ham b ers m ust b e tested to

ensure they w ork.

Mic higan’s task has therefore b een segmen ted in to sev eral phases of steps designed to b oth

ensure the c ham b er builders will ha v ea w orking readout system when they need it and to certify

the dev elopmen t path of the full A TLAS readout system as it ev olv es to its nal state. The

rst few phases are progressing in parallel. This is the dev elopmen t of a Mini Data AcQuisition

(MiniD A Q) soft w are suite and readout/testing of the c ham b er ASD and TDC protot yp es using

v ariations of the same soft w are and hardw are.

The A TLAS MiniD A Q is designed to run on a Windo ws NT platform, primarily implem en t-

ing soft w are and hardw are from National Instrumen ts as a means of accessing data from the

MDT c ham b ers through VME64 electronics. F or the 10K c ham b er tests CDF 96 c hannel

TDC b oards with L VDS fron t ends will attac h to the c ham b ers using a PENN designed am-

plier/sharp er/discriminator (ASD-8s). An A TLAS T ransition Card sp ecically built for this

purp ose will con trol the TDC op eration via the VME J2 and J3 bac kplanes. A VME residen t

CVXI-1149.1 b oard from Corelis, Inc. pro vides parallel I/O bits to/from the transition card,

thereb y con trolling the data acquisition op eration as a whole. The Corelis b oard also pro vides

JT A G p orts whic h will b e used in later electronics certication phases of our program. Ulti-

16

mately c ham b er testers will ha v e a Graphical User In terface equipp ed with buttons and p opups

to quic kly and easily guide them through the steps of acquiring data from the MDT c ham b ers,

th us assuring condence in the c ham b er op eration.

In later phases of electronics certication v ariations on this hardw are/soft w are sc heme will b e

emplo y ed in testing A TLAS MDT readout elemen ts as they emerge from the design path. These

elemen ts include the nal ASD and TDC c hips/b oards, the Cham b er Service Mo dule (CSM),

the T o w er Service Crate (TSC), and the in tegrated Timing, T rigger, and Con trol (TTC).

7.4 Muon Lev el 2 T rigger Algorithm Dev elopmen t

The A TLAS trigger is based on lev el 1 hardw are signals that are generated in azim uthal and

rapidit yin terv als call Regions Of In terest or R OI. F or the m uon system these R OI signals

are dev elop ed from Resistiv e Plate Cham b ers, RPC, for the barrel region and b y Thin Gap

Cham b ers, TGC, for the endcap region. A t lev el 1 the pattern matc hing is done in hard co ded

electronics. A t lev el 2 this initial R OI information will b e used along with the data from the

MDT system to rene the m uon iden tication and sharp en the P

T

threshold selection. An

imp ortan t goal for the lev el 2 trigger is to reduce the lev el 1 trigger rate b y a factor of 100.

As part of Mic higan’s fo cus on the MDT system, w ein tend to con tin ue to pursue the

dev elopmen t of algorithms for lev el 2 triggering. The approac h tak en utilizes the R OI lo cation

to rst examine the signals that formed the lev el 1 R OI trigger and to then dev elop a set of

roads within the m uon trigger cells, the RPC or TGC, consisten t with desired m uon trac ks,

i.e. ,abo v e the P

T

threshold for triggering. F or eac h suc h candidate m uon, the in tersection of

the road with the MDT tub es can b e dened. The pattern of MDT tub es hit in the in tersection

region further denes the road. The pattern of struc k tub es also denes a range of angles that

are c hec k ed for consistency with the road. With a self-consisten t road con taining hits from

the trigger c ham b ers and the MDT, additional computation with the drift times in the MDT

p ermits a t to b e made with signican tly b etter measuremen t resolution. This t lik e trac k

reconstruction generally m ust include the rejection of hits that are far from the tted tra jectory

follo w ed b y retting.

The algorithm dev elopmen t will require the selection and implem en tation of sp ecic actions,

the ev aluation of acceptance criteria for hits and roads, and the dev elopmen t and ev aluation of

tting and hit rejection mec hanisms. W ork in this area will con tin ue to b e done at Mic higan with

the Mon te Carlo ev en t sim ulations including bac kgrounds. The optimization of m uon detection

eciency and bac kground rejection is the ma jor fo cus with execution sp eed of the algorithm

as an imp ortan t constrain t. There are man yc hoices that m ust b e made and ev aluated in this

pro cess. There are also man y distinct means to accomplish the individual steps, e.g. , global

table lo okup vs. lo cal pattern sensing follo w ed b y global linking of lo cally sensed patterns.

The nal co de m ust execute in a time consisten t with the exp ected trigger rate and pro cessing

po w er and the tradeo b et w een m uon detection eciency and fak e trac k rate m ust b e suc h

as to yield acceptably high detection while pro viding adequate lev el 2 trigger rejection. Our

bac kground as leaders in the deliv ery of trigger hardw are and soft w are giv es us condence that

w e will mak e ma jor con tributions to this asp ect of A TLAS.

17

7.5 The Dela yLoc k ed Lo op of the DTMR OC TDC Chip

One of our electronics engineers, John Mann, has designed the Dela yLoc k ed Lo op (DLL) for the

DTMR OC TDC c hip. This ASIC, a collab oration eort b et w een Univ ersit yof P ennsylv ania,

Univ ersit y of Mic higan, CERN, Univ ersit yof W arsa w, and Manhattan Routing of NY Cit y ,

is for the A TLAS TR T. The DLL design uses an 8 stage reference c hain, made of 16 dela y

in v erters, whose output is fed to a phase detector and c harge pump. The phase detector and

c harge pump adjusts a con trol v oltage to sustain a dela y p er stage of 3.125 nsec when compared

to an externally-supplied 25 nsec clo c k. A separate dela yc hain, iden tical to the reference c hain,

is used to generate pulses to digitize the data. This data capture dela yc hain outputs 8 pulses

with a 3.125 nsec dela ybet w een successiv e pulses. John’s exp erience in design and testing

of DLL circuitry allo w ed him to con tribute to this pro ject with a minim um of startup time.

Since the DLL is a crucial analog elemen t within the TR T fron t-end, John’s w ork included a

detailed la y out of the dela y-c hain cells and extensiv e sim ulations of its p erformance. Additional

co op eration with the TR T fron t-end comm unit y is exp ected in the dev elopmen t of the merged

ASD/DTMR OC (called the ASTRAL) and in the testing of pro duction comp onen ts for the

TR T. Discussions ha v e b egun with the US A TLAS TR T Pro ject Manager, Harold Ogren, in

an eort to dene the resources a v ailable for Mic higan to participate in the fron t-end c hip and

b oard dev elopmen t/testi ng.

7.6 Review of A TLAS Computing

Homer Neal c haired the A TLAS Review of Computing Committee that submitted its nal

rep ort in late F ebruary 1999. This commi ttee w as assem bled to assess whether A TLAS com-

puting is on course to meet the needs of the pro ject during the construction, commissioning

and running of the exp erimen t. The rep ort con tains man y relev an t observ ations and recom-

mendations. The full rep ort is a v ailable on the CERN w eb[3]. The list of quotes b elo w is tak en

directly from the executiv e summary of the rep ort. The sp ecic quotes are c hosen b ecause of

their relev ance to the con tributions w e prop ose to mak e as stated in section 11. W e exp ect to

expand up on the ne con tribution b y Homer Neal with eorts directed to w ard closing some of

the gaps iden tied b y the committee. The list of quotes from the rep ort has four subsections,

in tro duction, observ ations, recommendations, and arc hitectural and distributed data handling

issues. Muc h of the rep ort fo cuses on the detector p erformance ev aluation soft w are, database

soft w are, the need for engagemen t of the soft w are talen t within the collab oration, and on the

dev elopmen t of collab oratory to ols for eectiv e co ordination of all eorts.

7.6.1 In tro duction

 \The ob jectiv e of this review is to assess the status of the strategic planning and progress

of A TLAS computing and to recommend actions that will help ac hiev e the collab oration’s

goals in this imp ortan t area".

18

7.6.2 Observ ations and ndings

 \W e nd a p oten tially serious shortage of ph ysicists dev oting ma jor atten tion to A TLAS

soft w are issues".

 \W e nd a need for impro v ed emphasis on training to successfully tap the existing A TLAS

talen t to help prepare the nal A TLAS soft w are".

 \W e b eliev e that A TLAS could do m uc h more to facilitate in teractions b et w een the in-

stitutes and CERN b y taking a leadership role in relev an t collab oratory R/D".

7.6.3 Recommendations

 \Detector-sim ulation, reconstruction and com bined-p erformance groups should b e as-

signed, together with the exp erts w orking on OO soft w are to da y , the task of pro ducing the

new detector sim ulation and reconstruction soft w are for A TLAS. Clear and w ell-dened

milestones should b e set".

 \It is essen tial that a common detector geometry b e used for b oth sim ulation and re-

construction. If the new geometry is dela y ed, existing sim ulation geometry should b e

temp orarily transferred, so that reconstruction soft w are dev elopmen t can con tin ue".

7.6.4 Arc hitectural and Distributed Data Handling Issues

 \Skilled p eople m ust b e found in the Collab oration as so on as p ossible".

 \Guidance should b e pro vided on the desired structure of database systems for the collec-

tion and storage of data from sub detector comp onen t fabrication and testing op erations".

 \W e recomme nd that collab oratory R/D initiativ es relev an t to the needs of A TLAS con-

tin ue and b e giv en the supp ort of the A TLAS managemen t".

8 Mic higan’s Cham b er Construction Activities

In the past y ear w eha v e made considerable eorts to conduct critical R&D and to dev elop

facilities and to ols for A TLAS m uon c ham b er pro duction. The follo wing sub-sections brie y

describ e our activities in these areas:

 R&D on Long T ub es

 Assem bly Area Dev elopmen t

 T ub e Assem bly and T esting

 Cham b er Construction

 Deliv ery Milestones

19

8.1 Long Drift T ub e R&D

The large c ham b ers to b e built at Mic higan and elsewhere will incorp orate long drift tub es

extending from v e to six meters in length. These tub es presen t sp ecial c hallenges that precip-

itate a n um b er of questions. P articular questions include: are cen tral wire supp orts required

to k eep the wire concen tric with the tub es, can this goal b e accomplished b y b ending the tub es

to follo w the gra vitational curv e of the wires, or can soft w are yield adequate resolution with

unsupp orted wires in straigh t tub es? The c haracteristics of these long tub es are suc h that,

1. The maxim um gra vitational sag of a 6 m long 50  m diameter tungsten wire at 375

g tension is ¦ 455  m. The o-axis wire can pro duce a non-symmetric time-to-space

function that degrades the tub e resolution and hence the momen tum resolution.

2. When high v oltage is applied there is an additional electrostatic de ection of the wire

that increases the time-to-space function asymmetry and p oten tially con tributes a degree

of mec hanical instabilit y .

3. The presence of am bien t vibrations can, in principle, induce oscillations of the wire. With

sucien t amplitude, these oscillations will degrade the tub e resolution and decrease the

electrostatic stabilit y of the wire.

T o address these issues lab oratory measuremen ts and computer sim ulations ha v e b een con-

ducted. A test station has b een built and instrumen ted with the ob jectiv e of accurately mea-

suring gra vitational sag, electrostatic de ections, and vibrational amplitudes of sense wires.

This station will b e augmen ted with a precision silicon telescop e ( < 10  m resolution) that

will allo w cosmic-ra y studies of the drift v elo cit y for candidate MDT gases. Computer sim u-

lations ha v e also b een done to in v estigate exp ected c hanges in the time-to-space functions for

axially oset sense wires. These sim ulations pro vide estimates of the resulting degradation of

momen tum resolution.

8.1.1 T est Station Results

The test stand holds a 5.63 m long tub e on v eev enly spaced, adjustable supp orts. The tub e

is aligned with these supp orts to within ab out 25  m using a laser-CCD surv ey instrumen t.

The radial lo cation of the 0.002" diameter sense wire w as measured with a microscop e that

view ed the wire through a small hole at the midp oin t of the tub e. The gra vitational wire sag

at a tension of 375 g w as measured and conrmed to b e consisten t within the tub e alignmen t

error with the exp ected sag of 412  m. The electrostatic de ection b ey ond the gra vitational

sag w as measured and found to b e 23  m  3  m at the op erating v oltage of 3100 V. This to o

is consisten t with exp ectation [4]. The electrostatic de ection for long tub es is th us a minor

p erturbation on the gra vitational sag.

These measuremen ts ha v e con vinced us that the long A TLAS m uon tub es do not require cen tral

wire supp orts for electrostatic stabilit y . The question remains whether external vibrations can