Activity on GEM by the Rome group since last meeting

Transcription

1 OLYMPUS Collaboration DESY 24/Feb/21 Activity on GEM by the Rome group since last meeting Salvatore Frullani / INFN-Rome Sanità Group 1

2 Outline DESY test beam 9-2 December SBS Technical Review JLab 22 January Test al JLab in high luminosity environment (PREX) March-May DESY test beam June-July Electronics status Plans 2

3 Prototype (1x1 cm 2 ) 2 GEM available in Rome for Test beam, a 3rd in Lab 3

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6 Different (e,e h) experimental configurations Experiments Luminosity Tracking Area Resolution (s cm 2 ) -1 (cm 2 ) Angular (mrad) Vertex (mm) Momentum (%) GMn - GEn up to x15 < 1 <2.5% and 5x2 GEp(5) up to 4x12, x2 and 8x3 Most demanding <.7 ~1.5 ~1.5% SIDIS up to x12, ~.5 ~1 <1% 4x15 and 5x2 High Large Down to ~ 7 μm Rates Area spatial resolution Maximum reusability: same trackers in different setups 6

7 Front Tracker Geometry SBS Tracker Chambers configuration x6 GEp(5) SBS Modules are composed to form larger chambers with different sizes Electronics along the borders and behind the frame (at 9 ) cyan and blue in drawing X(4+4) Aluminum support frame around the chamber (cyan in drawing); dedicated to each chamber configuration Back Trackers Geometry 7

8 Electronics layout and outer support Green = FE card Cyan = Module frames Cards and modules are supported by an outer aluminum frame which runs all around the chamber. Optimization is in progress. Red= Outer Support Frame 8

9 Dec/9: first beam test at DESY-II test area (low intensity electron beam from 1 to 6 GeV) of 2 1x1 cm 2 2D prototypes + Gassiplex electronics Characterize the small chamber Test software treatment of data (to be implemented in the FPGA of new electronics) Prepare for the full size module test with new electronics Gassiplex analog output sent to an external ADC (VME module) and put in DAQ -> very simple system already available to test and learn GEM behaviour 9

10 DESY beam test in Dec/9: setup 2x 1x1 cm2 GEM prototypes Silicon Tracker + scintillator fingers HV Power Supply Beam 1

11 Profile axis Profile axis 1 DESY beam test in Dec/9 - pedestals hprofo Entries Mean Mean y RMS RMS y hprofo1 Entries Mean Mean y RMS RMS y Baseline subtracted pedestals adc-bline[] {((((ch>)&&(ch<24)))*(((nhit[]>18)&&(nhit[1]>18))))*((bline[1]<88))} htemp Entries Mean RMS adc-bline[1] {((((ch>48)&&(ch<72)))*(((nhit[]>18)&&(nhit[1]>18))))*((bline[1]<88))} htemp Entries Mean RMS Gassiplex Readout (not optimized for negative charge), 7 ns shaping time adc-bline[] adc-bline[1] 1 1

12 DESY beam test in Dec/9 - event example Ar/CO2 7%/3% 3 GeV Electron Beam ΔGEM = 41 V Vdrift = 2.5 kv/cm VGEM = 2.5 kv/cm Vind = 3.5 kv/cm Axis Event Profile Axis Event Profile adc-bline[] {ch==13} 3 1 ava Entries 227 Mean RMS ava1 Entries 225 Mean 11.5 RMS Single Event htemp Entries 1392 Mean RMS Cumulated (Beam profile) adc-bline[] 1 2

13 1 Axis Charge DESY beam test in Dec/9 x/y correlation chargei1 Entries Mean 1252 RMS x/y charge correlation chargei2 Entries Mean x 1218 Mean y RMS x 588 RMS y ΔGEM = 41 V Vdrift = 2.5 kv/cm VGEM = 2.5 kv/cm Vind = 3.5 kv/cm Axis Charge Ratio 35 3 chargeir Entries Mean.9992 RMS.3996 Axis Charge chargei Entries Mean 1212 RMS 66.2 Maximum charge in strip Total Charge in cluster Axis Charge chargem1 Entries Mean RMS x/y charge correlation chargem2 Entries Mean x 54 Mean y RMS x RMS y Axis Charge Ratio 12 chargemr Entries Mean 1.94 RMS.1666 Axis Charge chargem Entries Mean 54 RMS

14 Slow Control HV management is not trivial! 7 HV levels must rump up/down coherently Low pass filters 1 4

15 Committee: JLab SBS Technical Review B.Mecking, P. Brindza, E. Chudakov, D. Dougthy, B. Kettzler, M. Titov GEM activity presented and discussed in details Electronics schemes, possible problems and solutions, plans discussed in depth Approved plan that foresees costruction of one large GEM module (4x5 cm 2 ) tested under beam with the new electronics before summer vacations 1 5

16 Test at JLab PREX March-May Parity REX (Lead-Pb Radius EXperiment) Parity Violation Experiment 1 6

17 Very high luminosity experiment ( at 5 μa -> 9 MHz; now 8 μa -> 1.5 GHz) Integrated current at 3 Hz helicity switch, no tracking Aiming at high precision: Background subtraction as well as optics studies require tracking measurements (at much lower current) GEM Gassiplex (integration time 1μs) -> 1 MHz/cm 2 -> beam few 1 na APV25 (int. time < 1 ns) -> 1 MHz/cm 2 -> beam few μa 1 7

18 Hit rate not an issue Rate capability Ar/CO 2 /CF 4 (6/2/2) Triple GEM Poli Lener, PhD Thesis - Rome

19 DESY Test Beam June - July Test of small (1x1 cm 2 ) and large (4x5 cm 2 ) GEM with new electronics with the aim to fully characterize their performances (efficiency, resolution, stability,etc.) for tracks at different incident angles and different gas mixtures 1 9

20 Front End (2) Based on APV25 chip. We bought 6 naked chips. 128 channels per card (1 APV). Dimensions: 5 x 9 mm 2 Discrete input protection (2D + C) I 2 C Debug Panasonic FPC connectors Protections APV25 PSU I/O connectors Analog output buffer 2

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22 5 front end cards available, at moment only 1 has APV25 bonded (soon all 5) Contract with EES (Electronic Engineering Service) covering all the prototyping phase and a large part of production phase Under tests at laboratory bench with a specially designed test card to provide power supply,control signals and receive back analog signal. Test under beam at JLab PREX in May, even if VME module not available (with the same approach used for the tests with Gassiplex) 2 2

23 Electronics Components GEM FEC ADC+VME Controller DAQ 2D Readout General Criteria: Minimize development time Minimize material of FECs (which are partially along the particle path) Be compliant to JLab DAQ Maximize flexibilty (at least during prototyping) Thanks to Michael Böhmer and Igor Konorov 2 3

24 2D Readout Electronics Components GEM FEC ADC+VME Controller DAQ 49.5 mm 8 mm 8 mm Main features: Use analog readout APV25 chips (wire-bonded on standard PCB, no ceramics): proven to work in COMPASS ZIF connector on the GEM side (no soldering on readout foil) Minimum electronics components (front-end + VME custom module) Copper connection between front-end and VME Up to 1 m Thanks to Michael Böhmer and Igor Konorov from TUM for very productive discussions on the design of the APV25 based FrontEnd card 2 4

25 Readout VME module(1) Main features: o Digitization of 16 APVs (248 channels) o APV serial stream decoding o Zero suppression o Big memory buffer, multi event o Possibility to implement SOC: Flash, Ethernet, Serial o Remote logic reconfiguration, hot swappable o Dual configuration: goal: VME64x compliant backup: Stand Alone (with optical link) 2 5

26 VME64x Controller VME controller hosts the digitization of the analog signals coming from the front-end card. It handle all control signals required by the front end card Compliant to the new JLab/12 VME64x VITA 41 (VXS) standard From the VXS backplane: 1. Trigger L1/L2 2. Synch 3. Clock 4. Busy (OUT) (duplicated on front panel) We intend to make it accessible by standard VME as well (with reduced functionality) Design with the possibility to detach the ADC subcomponent to extend FEC- VME64x distance (expected to be ~8-1 m) 2 6

27 For each GEM Luminosity 1x1 cm 2 module (4 μm pitch): 4 front end cards + 1/4 VME module Total: 24 fec VME modules 2 7

28 VME Controller Status Scheme and PCB completed and sent to EES for construction of 2 prototypes Prototype should be available in 3-4 weeks -> within March -> bench test -> GEM Software for FPGA in progress:vme interface 32->64 bits,slow control (ADC,I2C,PLL), APV acquisition,.. Plan: to have a working module in May to be used before the end of run of PREX. Should certainly be ready for DESY test beam run in June-July 2 8

29 Conclusions At the moment no major problems are seen. GEM chambers are on their way to JLab and there it would be easy to discuss with Michael Kohl construction details (already started discussions), collaboration with data taking and learning process -> analysis essential to develop FPGA program New electronics plans foresee availability of full prototype in time to be tested under beam before summer vacations (August) All seem on track. 2 9