Nilanga Liyanage University of Virginia

UVa GEM TeamDr. Kondo Gnanvo, Dr. Vladimir Nelyubin, Kiadtisak

Saenboonruang, Chao Gu, Xinzhan Bai , Jie Liu, Seth Schcher, Taylor Scholz

GEM Chambers for the Polarimeter Trackers

Front TrackerGeometry

x6

18 modulesIn Italy

50 cm x 40 cm and 50 cm x 50 cm Modules are assembled to form larger chambers with different sizes

Front tracker: Six 40 cm x 150 cm GEM layers built in Italy – INFN

Polarimeter trackers: Eight 50 cm x 200 cm GEM layers

to be built in Virginia2

40 modulesAt UVa

GEM module production starting nowTotal Area ~ 16 m2

SuperBigbite GEM Trackers

4 GEMs with APV25-front end for card seach of the 8 Polarimeter chambers

New design for the SBS GEMmodules for polarimeter trackers by Kondo Gnanvo

Need 32 modules + 8 spares

• Setup and instrumented the GEM lab

• Constructed two 40 cm x 50 cm prototypes based in the Rome design

• First chamber under testing now.

• Kondo finalized the new design based on lessons learned.

Progress so far

5

N2 HV Test Box

Pico-ammeter

Storage Shelves

Stretching Device

Display

Monitor

Storage Cabinet

Ultrasonic bath

Our Class 1000 Clean Room (3.5 × 3 m2 )Built originally for the BigBite drift chambers constructionLocated in a large (4.5 m x 9 m) semi-clean area.Additional clean room to be added later this year

UVa GEM Lab•Mechanical stretching device•HV Test N2 Gas box•Keithley Picoammeter 6487 with 500 V source Ohmmeter•Ultrasonic bath (Elmasonic S900H )•APV25 based readout systems with 5000 channels for testing GEMs•Wiener MPOD High Voltage system

6

N2 HV Test Box

Pico-ammeter

Storage Shelves

Stretching Device

Display

Monitor

Storage Cabinet

Ultrasonic bath

Our Class 1000 Clean Room (3.5 × 3 m2 )Built originally for the BigBite drift chambers construction

UVa GEM Lab•Mechanical stretching device•HV Test N2 Gas box•Keithley Picoammeter 6487 with 500 V source Ohmmeter•Ultrasonic bath (Elmasonic S900H )•APV25 based readout systems with 5000 channels for testing GEMs•Wiener MPOD High Voltage system

7

N2 Box for HV test of GEM Foils

Resistors soldered on GEM

Assembly Steps of the SBS GEM Prototype at UVa

8

9

Preparation of the readout board

Stretching of GEM foils

Assembly Steps of the SBS GEM Prototype at UVa

10

Test frames glued

X-axis t1

Y-axis t1

X-axis, t1 + 25 ns

Y-axist1 + 25 ns

First results from SBS GEM Prototype: MPD readout

First results from SBS GEM Prototype: SRS readout

Distribution of the mean ADC count: Gain uniformity Y-axis

(mm

)

X-axis (mm)

X/Y (ADC) = 1.12

First results from SBS GEM Prototype: SRS readout

Distribution of the mean ADC count: Gain uniformity Y-axis

(mm

)

X-axis (mm)

X/Y (ADC) = 1.12

14

Cosmic test results – from 10 cm x 10 cm chamber

SBS GEM Chamber Gain Calibration

• Test pulse = 360 mV, Capacitor = 3.3 pF Equivalent charges = 7.2 Million e-

• Injected charges = Equivalent charges / Attenuator attenuation 3dB to 39 db

Pulse generator360 mV

Attenuator3db to 39 db

Capacitor box3.3 pF

GEM chamberreadout

50 m

APV25 Electronics(MPD and SRS)

External trigger Signal form one strip

APV 25 Gain Calibration

Just did this calibration for both SRS and MPD systems

Pedestal Noise – RMS distribution for 128 stripes

ADC chan.

Module of 50x50cm2 to replace the 40x50cm2

• 32 modules to be built instead of 40 for the 8 Polarimeter chambers

Wider GEM frames along x-axis • Width of 30 mm instead of 8 mm• Better stretching • alignment holes away from active area

Wider readout support frame along x-axis (74 mm)• Room for strips connectors and GEM

HV sectors electrodes

No protective resistors on the GEM foils External resistor boards

Gas system same as in Evaristo design

New design for the SBS GEM polarimeter trackers –from Kondo

Gas inletGas outlet

window

Drift cathode

GEM foil 1

GEM foil 2

GEM foil 3

GEM Foil with HV sectors

12 H

V se

ctor

el

ectro

des

Alignment holes

gas h

oles

600 mm

590 mm

562 mm

562 mm

GEM Frame with outer frame572 m

m

528 mm

572 mm

512 mm

512

mm 562 mm

562 mm

GEM Frame without outer frame after assembly

572 mm

512 mm

512

mm

528 mm

GEM Foil with HV sectors

GEM Foil with HV sectors after assembly

600 mm

528 mm

GEM Foil with HV sectors on its frame after assembly

Readout Support with its outer frame572 m

m

528 mm

Up to 660 mm to be decided with Rui

245

mm

10 m

m10

mm 24

5 m

m

100

mm

100

mm

562 mm

562 mm

Readout Support with its outer frame

Keeping the outer frame during assembly

Fixation holes

Alignment holes

Readout support after assembly

528 mm

Up to 660 mm to be decided with Rui

Y-Strips connectors on flexible PCB

Y-St

rips

conn

ecto

rs o

n fle

xibl

e PC

B

80 mm

49.5 mm

APV-25 FE cards (Italian Electronics) on scale on the readout board Panasonic connectors

X/Y readout board with Panasonic connectors and Italian APV25 based electronics

SBS GEM with APV25 FE cards (Italian Electronics)

Frame Design

4 SBS GEMs with APV25-FE for each of the 8 Polarimeter chambers

• Install new clean room and upgrade equipment.

• Parts for two 50 cm x 50 cm prototypes ordered – expect delivery by December.

• Complete the construction of prototypes by February.

• March to May 2013.• Characterize the chambers, finalize the design and order

parts for 8 (?) chambers.• Order Electronics for 8 chambers

• Proposed production schedule• May 2013 – May 2014 – 8 modules• May 2014 – May 2015 – 16 modules• May 2015 – May 2016 – 16 modules

It is crucial that we get our GEM foil orders out as soon possible.

Future plans

Cosmic test results