z. papandreou & e. smith gluex collaboration meeting, sep. 19/2008 1 1 bcal construction &...

Z. Papandreou & E. SmithGlueX Collaboration Meeting, Sep. 19/2008 1

1

BCAL Construction & Readout Update

Contributions by:•SiPMs:

•K. Janzen, A. Semenov, C. Zorn, F. Barbosa, SensL

•Simulations: •S. Katsganis


2

Overview

• BCAL Construction– Start in Spring ‘09?

• SiPM Progress– JLab, Regina, SensL: meetings, reports– Performance: PDE, DR, array assembly

• Alternative Readout• Simulation Issues


3

Construction - Two Modules(two presses)

Timeline (work days) Tasks for a Pair of Modules

D-0 + 3 Complete the lead swaging and rolling of the swaged sheets intomarked rolls indicating relative orientation for matrixconstruction. Complete the sorting and bundling of fibers foreach layer required for the module.

D-0 + 4 Start the construction of the matrix: laying and gluing of the firstbase lead sheet along the centerline and within the alignment jigs.Press and let cure overnight.

D-0 + 5 Trim the base lead sheet to matrix construction length andremove any hardened epoxy along the ends that may interferewith matrix construction. Start the matrix construction. Nominalaim is the completion of the first eight layers. Carry out QA ondimensional tolerances each morning of the construction.

D-0 + 30 Complete the matrix construction of ~201 layers. Inspectcompleted module and record exact height measurements alongits length.

D-0 + 31 Remove the module from the press frame (requires craneoperation) and prepare for next matrix construction.

D-0 + 32 Rough trim the two readout ends of the module to remove fibersand epoxy from sticking out. Ready the two ends for finalmachining and polishing.

D-0 + 33 Install the module on the CNC machine at CPP and check jigalignment. Start machining the two ends.

D-0 + 36 Complete the machining and polishing of the two readout ends.QA: Inspect the optical integrity and dimensional tolerances andprepare module for shipping to Regina.


4

Construction - Four Modules(four in a shipment)

Work Days Calendar Days Task for Four Modules10* 10* Swage all lead sheets and bundle fibers for

four modules.4 4 Glue base lead sheets to the Al base plates

for four modules, cure and trim.50 70 Matrix construction of four modules on PF1

and PF2.4 4 Craning and rough trimming of the two

ends of each module.8 10 Machining and polishing of the two readout

ends.4 4 Load and transport from Edmonton to

Regina for final machining.16 22 Modules will be machined along long sides

to the specified 7.5° ta peris completed andinspect edfor tolerances (QA).

7 9 Modules are shipped directl y from RossMachi neShop t oJLab? Final testi ng withcosmi c r ays will be done at JLab.

91 121 Total number o f working/calendar daysf or fou r modules fr om start ofconstruction t odelivery t oJLa .b

* Lead swaging and fiber sorting can proceed in parallel with matrix construction, oncethe firs t t womodules are bei ng built, therefore t 10he days are not counted i nthe total.


5

Construction Logistics

• Total calendar days for delivery of 49 modules: 817 days from D-0.• Project Coordination

– Base Crew: undergraduates– Construction Manager: one person, full time over the entire construction

period; will be trained in construction techniques and will be responsible for day-to-day supervision and QA of the matrix build, as well as crew contacting and scheduling, and reporting. Draft ad exists.

– Training: Regina faculty and staff will do the initial training of the construction crew and the Construction Manger (CM). From then on, the CM will take over this task for the subsequent crews with assistance from Regina, during carefully timed trips of the latter to Edmonton.

– Chief Machinist: Gilbert Lachat (UofA/CPP) – Supervising Engineer: Jan Soukup (UofA/CPP)

• Oct. 15 visit to U of Alberta: Elke, Elton, Tim, George, Zisis


6

BCAL Readout Considerations• Technical specifications: outlined in GlueX-doc-795-v17

– SiPM tests are underway; past/ recent results of tests of fine mesh PMTs• Geometry: especially related to acceptance gap between BCAL and FCAL

– Light guides and inactive material is different for the two options. We need to simulate the effect of each

– Precise configuration of light guides for FM PMTs on the upstream end, where the field at the end of the BCAL exceeds 0.5 T

– Detail description of cables and electronics on each detector• Granularity: optimization of distribution between inner and outer

detectors– Which detectors should have discriminators and TDCs– Study of signal splitting, choice of discriminator; this has an impact on

no of cables• Resolution: Complete simulation studies for correct thresholds for

the FM– Studies of timing resolution. Realistic simulation for both photons &

charged particles– Resolution for various geometry options (mentioned above)


7

Roadmap

• SensL is not meeting our PDEDR requirement

• Schedule delay: 3-4 months

• Contract extended• Sept 22 decision for

array cell type

ContractStart


8

Targets & Device Details

• Devices:– SPMMicro– SPMArray– SPMPlus

• Processes:– Trenching– Gettering– Electronic

s

SPMMicro Test Samples @JLab (+ 2 @Regina)

(GlueX-doc-795-v17)

• A20HD (3 samples) - 1 mm^2 - (circular pi/4 mm^2 area)- Getter 2 - 848 microcells - FF = 43%• A35HD (3 samples) - 1 mm^2 (circular) - Getter 2 - 400microcells - FF = 59%• A20HD (3 samples) - 3x3 mm^2 (square 2.85 x 2.85 mm^2)- Getter 1 - 8640 microcells - FF = 43%• A35HD (3 samples) - 3x3 mm^2 (square) - Getter 2 - 3640 microcells - FF = 59%• A35HD (3 samples - 1 defective) - 3x3 mm^2 (square) - Getter 1- 3640 microcells - FF = 59%

No trenching


9

3.88, 6

10, 13.2

5, 10

20, 18.6

8, 13.5

4.25, 9.5

0

2

4

6

8

10

12

14

16

18

20

0 5 10 15 20 25

Dark Rate per 3mm SPM

PDE (%)A20H Device

A35H Device

Gettering - PDE/DR effect

(SensL, C. Zorn)

(No Getter)

(Getter #1)

(Getter #2)

(No Getter)

(Getter #1)

(Getter #2)

• Gettering process drives DC reduction– Weaker effect on edge intensive device (20um)

– Minimal DC reduction going from Getter #1 to Getter #2 processing for A20H device.

• PDE reduction significant with the introduction of Gettering (more than originally anticipated).

• Closet Device to specifications:– A35H Getter #1 process: 13.5% PDE and

8MHz DC per SPM.


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Specification: PDE vs Dark Rate

Design Goal(fixed resolution) (0.12, 42)

(GlueX-doc-795-v17)

13/16

Scaled by x16

20% sampfrac


11

Electronics and Timing• SPMPlus TIA Boards, labeled 080723 #2 and #3.

– Frequency response, transient simulation, pulse response– Optimization of the rise time and gain possible once final

sensors are available and input capacitance is fully characterized.

– SPMPlus electronics boards are well behaved and exhibit very

low output offset voltage.

• Baseline shift

• Noise at different frequencies

• 2nd pulse

(GlueX-doc-1024)

11 ns rise time-200 V offset

no abnormalitiesin tail


12

SPMMicro: Performance+ 20 C

May

Sept


13

SPMMicro: DR & Cross Talk

Correct by 13/16

Extrapolated x16

MaySept


14

SPMMicro: 90Sr

• Devices tested:– 1-mm2 A20HD/A35HD, 9-mm2 A20HD

• IV scans: Vbr origin slight diffs• 90Sr source + green fiber tests:

– good rise and fall times;– level shift, no second pulse, lots of

noise in the analog pulses, pedestal resolution from SPM

• Results: – Nice p.e. peaks at diff overbias– Good linearity; p.e. lines intercept at

+0.85 V– Good linearity also on plot versus no.

of p.e. for different overbias curves

(GlueX-doc-1066)


15

SPMPlus: Assembly Issues

• Setup: laser, fiber, SMA connector, green fiber, 1mm collimator, x-y stage, scope

• Laser at 2.5MHz, 60ps pulse

• Over-bias: +2V (at 28.3 V)

• 10 ns rise, 70 ns decay• Uniformity improved (8 cells within 10%, 12 within 20%)

(GlueX-doc-1024)

• Type 1: Low Gain Output /Good Timing– This pixel behaviour results in as much as 2x

reduction in optical output over normal pixels. – Problem corrected by optical binning procedure.

• Type 2: Dead Channels– 50% yield on early assemblies based on electrical

IV measurements.– Root cause was with subcontractor process where

poor metal adhesion was identified due to insufficient adhesion layer resulting in delamination of the metal from the glass.

– Latest builds (Build ID: 080408_1_10) have shown 100% yields on a batch of 10 array builds (i.e. all 160 channels fully functional). No type 2 defect observed indicating that new adhesion process has fixed the fail mode.

Pixel Failures

Wafer Selection


16

SPMPlus: No. of p.e. - summary

Test Setup No of p.e./MeV(@module end with cell size correction)

Comments

Hall-B cosmics XP2020+ blue fibers 4-5 Mod-1, 3.8 cm readout

Regina cosmics Burle 8575+blue fibers 4 Mod-2, 3.8 cm readout

Regina cosmics EMI + green fibers 3 Mod-2, 2 cm readout

Regina cosmics SiPMPlus + green fibers 4.6 (maybe 5.3 if all cells worked)

Mod-2, 2 cm readout

Regina 90Sr A20HD+ green fiber 7.5

(x2x0.15MeV=~2pe)

Single fiber

(GlueX-doc-1069 and 1066)

(see Beni’s talk (doc-1106) for new results - 90Sr+fiber)


17

Thinner Lead Sheets?• Objectives

– increase sampling fraction lower threshold and relax demand on PDE

• GEANT3 simulations with new geometry; they agree with FLUKA 2006.3b

Glue

Glue

0.26mm 0.5mm Pb

0.20mm 0.2mm Pb

0.20mm

Rear+sides

1.0mmPb

0.2mmPb

KLOEsamples

nominal

candidate?

nominal

candidate?

Clad


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In a nutshell…

• A20HD SPMMicro has yielded PDE of ~6%- 9% in the +1.5V to +3V range, consistent with SensL’s numbers

• A35HD 3x3mm2 extrapolated/measured ~12-13%, DR ~ 80-90 MHz

• SPMPlus: no. of p.e. consistent with PMTs with blue and green fibers

• Significant improvement in Si wafer selection: optical binning

• Significant array manufacturing improvement: no delamination

• Progress is promising, but we need SPMMicro A35H PDE >12% and DR<40MHz, plus fully functioning SPMPlus arrays

• Upcoming decision: base cell for SPMPlus arrays

• But, we are not out of the woods…so, look at Plan B


19

BCAL Alternative ReadoutBCAL Alternative Readout Comparison standard and alternative readoutComparison standard and alternative readout

alternative readout based on fine mesh Hamamatsu PMTs:alternative readout based on fine mesh Hamamatsu PMTs: New segmentation: inner (2 x (3x3) channel) 1” FM-PMT New segmentation: inner (2 x (3x3) channel) 1” FM-PMT

outer remains (2 x (2x2) channel) 1.5” FM-PMT outer remains (2 x (2x2) channel) 1.5” FM-PMT

performanceperformance operate in magnetic field up to 0.5 Teslaoperate in magnetic field up to 0.5 Tesla

upstream B-field > 0.5Tupstream B-field > 0.5T increase light guide fromincrease light guide from

10 cm to 55 cm10 cm to 55 cm

(Courtesy of Elke)

Disadvantage:Disadvantage: Cost increase by ~350k$Cost increase by ~350k$


20

Concepts for FM PMT housing


21

Light configuration studies


22


23

Simulation studies needed

• Resolution comparison: 6x4 vs 3x3 segmentation• Improved simulation of resolutions

– Include realistic threshold for FM option– Studies of timing resolution

• Study impact of inactive material at the end of BCAL on acceptance

– Inactive material includes light guides, light detector, cables, dark box or cover, etc.

– Comparison between SiPM and FM options

– How many (which) changes in geometry should be studied?

(see Blake’s talk (doc-1101) for newest results)


24

Backup Slides


25

Carl’s Setups

N

PDE

Getter


26

Gettering Tests


27

• A20HD 9mm2 measurements are robust; extrapolate to A35HD 9mm2 PDE.

• A35HD has better resolution.

•PDE under identical geometries and illumination conditions:•PDE1mmA35HD/PDE1mmA20HD=1.35

SPMMicro: A35HD vs A20HD 1mm2

PDE9mmA35HD=1.35*PDE9mmA20HD=~12Carl: ~13%

Solid angleeffect

projected


28

SPMMicro: Laser

• Kathryn’s details…

(Regina June 30 Report)


29

SPMPlus: No. of p.e. - setup

(GlueX-doc-1069)


30

Layout of fine mesh pmts


31

mechanically not possiblemechanically not possiblenominal designnominal designalternative designalternative design

BCAL Readout Possibilities