Forward scintillators in ATLAS: cryostat and MBTS

CERNDubna

Michigan State UniversityUniversity of Texas-Arlington

presented by J. Huston

Michigan State University(apologies: some useful drawings captive on laptop, in for repairs)

D4D5 D6

B11 B12 B13 B14

A12 A13 A14 A15 A16

B15

E1,2

E3,4

E3 C10 B11 E1 D5 A14 - A15 B14 D6 A16 - -

D4 A12 A13 B12 - B13 - - - - B15 -

1.0 1.1

1.2

1.4

1.6

ITC Scintillators

(cryostat (or crack) scintillators)

(gapscintillators)

Crack Scintillator (E3, E4)

ATLAS IC Scintillator

R. Miller

Dimensions are in mm with a tolerance of ± 0.1 unless stated otherwise. Dimensions in parentheses are in Inches

DRAWNDATEPROJECTMATERIALTITLEDWG. NOSCALE

NOTES:

1.

MICHIGAN STATE UNIVERSITY HIGH ENERGY PHYSICS

REV

ASSEMBLY

A

HEP-B-025-368

227

140

885

Mounting bracket

Outer End piece Optical connectorsockets (2) pinned and sealed into end piece

Bottom cover panel is epoxied to end pieces.Black felt light seals line the surfaces in contact with fibers or scintillator edges.Top cover panel overlaps the bottom cover and end pieces and is taped at the edges.

Compression plate with set screws in same holes as mounting screws

6 mm thickPVT Scintillator, wrapped in Tyvek

OpticalIsolators on edges as necessary

(6) WLS Fibersfor cell E3

Inner End piece

Cell E3478

Cell E4362

19 8-14-01

1:5

C(1/8 x 3/4) pin

E4E3

(6) WLS Fibersfor cell E4

Mounting Proposal

ATLAS ITC Scintillator

R. Miller

MICHIGAN STATE UNIVERSITY HIGH ENERGY PHYSICS

REVDRAWNDATEPROJECTMATERIALTITLEDWG. NOSCALE

HEP-B-025-

227

DR = 885

140

Z=3560

Z=3540

R=1453

GAPSCINTILATOR

INTER-CRYOSTAT SCINTILLATOR MOUNTING

137.

117.

R-PHI VIEW R-Z VIEW

Pin aligns inner end to slot in next ctr.

9-21-01 E

MOUNTING

1:5

Dimensions assume 2 mm between Ctrs.

Cell E4362

Cell E3478

371

E4E3

8*

15*

25

13

20

R=2313

MOUNTING DETAIL

50

10

(2) M4 x 15Socket Hd. CS attaches crack ctr. to bracket

(2 ) M8 x 30Flat Hd. CS Ctrsunk attaches bracket and gap ctr. to EB end plate

Shim as neededto clear LAr Cryost.

eta=1.20

Bracket

R=2288

R=2260

CRACKSCINTILLATOR

* Indicates Envelope DimensionNOTES:

Bar is Integral to crack ctr.

Bar is Integral to gap ctr.

LAR CRYOSTAT

TILECAL EB

View of 2 cryostat shells

mounting bracket

Closeup

Bracket in final position

Bracket in final position

ATLAS ITC Scintillator

R. Miller

MICHIGAN STATE UNIVERSITY HIGH ENERGY PHYSICS

REVDRAWNDATEPROJECTMATERIALTITLEDWG. NOSCALE

HEP-B-025-

227

DR = 885

140

Z=3560

Z=3540

R=1453

GAPSCINTILATOR

INTER-CRYOSTAT SCINTILLATOR MOUNTING

137.

117.

R-PHI VIEW R-Z VIEW

Pin aligns inner end to slot in next ctr.

9-21-01 E

MOUNTING

1:5

Dimensions assume 2 mm between Ctrs.

Cell E4362

Cell E3478

371

E4E3

8*

15*

25

13

20

R=2313

MOUNTING DETAIL

50

10

(2) M4 x 15Socket Hd. CS attaches crack ctr. to bracket

(2 ) M8 x 30Flat Hd. CS Ctrsunk attaches bracket and gap ctr. to EB end plate

Shim as neededto clear LAr Cryost.

eta=1.20

Bracket

R=2288

R=2260

CRACKSCINTILLATOR

* Indicates Envelope DimensionNOTES:

Bar is Integral to crack ctr.

Bar is Integral to gap ctr.

LAR CRYOSTAT

TILECAL EB

Special ITC brackets

Inner radius

Counters held together by pins in one module fitting into slots in neighbor module

Cryostat scintillator status as of 2004

Optics, PMT’s, electronics and even mechanical shells were available

Scintillator purchase was a victim of management contingency and the cryostat scintillators were on the upgrade path

In the last few months, thanks to Marzio and Howard Gordon, the money is now available for construction and installation

Scintillator has been shipped from CERN to MSU yesterday

~2.5 month delay Construction will still be

complete during summer

…and,to save money, we will use polystyrenescintillator provided by Dubna, rather thanthe PVT scintillator from Bicron;factor of 2 less light yield, i.e. more like 2-3 pe/mip calibration issues

Same WLS fibers as for gap scintillators

MBTS counters

2 segments in ; inner segment covers pixel detectors

Readout Scintillator is polystyrene-

based, 2 cm thick Readout is by WLS fibers

running along division between L/R scintillator segments plus through sigma grooves in scintillator

Struggle to be able to trigger on MIP’s

increase light yield using every trick we know

Will also crank up HV to 900 V WLS fibers welded to clear

fibers to produce a pigtail which will mate into 1/8 of cryostat scintillator optical connections

after commissioning cryostat detectors will be re-connected

Scintillator

Scintillator has been produced by Dubna same scintillator as used for CDF central pre-radiator

upgrade currently at CERN, awaiting shipment to MSU later

this week ~2.5 month delay…

…construction will still be complete in September will continue to test counters using ATLAS

electronics readout chain at the U. of Chicago …and installation will take place this fall/winter

New decision

• MBTS scintillator and boronated polyethylene moderator will be mounted together in same can

MBTS counters are never removed; they just slowly die but continue to moderate

Moderator has to be machined back to 30 mm

currently looking for vendor envelope of MBTS + moderator is 57 mm

New drawings of moderator + MBTS

…still have to be approved

3547

3606

MBTS drawings

Installation work

This fall/winter, the gap and cryostat scintillators will be installed on EBA and EBC maybe delay in current schedule, but roughly Nov

and JanDuring these times, teams from the institutions

listed on front page will be at CERN and will also work on installation of MBTS counters + moderator working with shielding group all details not worked out yet, but Ron Richards is at

CERN for next few weeks to coordinate installation is designed to be relatively

straightforward