ALICE TPC UPDATE GEM AMMETER ICNUNAM M Sc

ALICE TPC UPDATE GEM AMMETER ICN-UNAM M. Sc. Javier Ruiseco Dr. Guy Paic M. Sc. Enrique Patiño FCE-BUAP Dra. Aurora Vargas Dr. Sergio Vergara Ing. Ricardo De Gante

INTRODUCTION � Read Out Chambers are going to be replaced by new technology due to read out rates. � Gas Electron Multipliers “GEMs” were chosen to facilitate the read out rate at 50 KHz. M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 2

GEM 1) GEM arquitecture example 3) GEM’s foil. M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 3) A closer look into a GEM’s foil. 3

Why an Ammeter is needed? � Due to electron multiplication, sometimes, due to high ionization, sparks occur, and they tend to damage GEM’s foils. � Therefore, a current monitoring system is needed to watch out for sparks without introducing noise to the GEM amplification!. M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 4

The Ammeter First Prototype: Microcontroller M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 5

Disadvantages �Microcontroller’s ADC resolution (0 - 0. 6 V) �Greater noise induction �Programming In Situ �Fixed sampling rate �The 8 or 12 channels are on the same PCB M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 6

Ammeter: Second Prototype 3 3 3 Advantajes of the second prototype: -Introduces an FPGA as central processing, which controls all channels. -Sampling rate can be easily reconfigured. -Each channel on a single daugther board. M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 7

GBTx Ø Bidirectional radiation tolerant chip. Ø Provides: • Timming & Trigger Control • DAQ • Slow Control M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 8

M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 9

Our DAQ System M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 10

1. FPGA 2. Wi. Fi module 3. Lemo connector board 1 2 3 M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 11

Tests and Results � Connected the ammeter in series on Gem’s Top Layer 1. M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 12

Thick GEM with Saturated Voltages � On our TGEM, this values are the maximum to prevent damaging the GEM. �Drift: -1630 V �Top 1: -1600 V �Bottom 1: -900 �Top 2: -880 V �Bottom 2: 0 V M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 13

Monitoring Note: 23 k samples ~= 1 hour Duration of test: aprox. 2 hours M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 14

Osciloscope Detection with this Configuration • The noise produced by the ammeter connection is so low that it cant be measured. With ammeter; 100 m. V/div No ammeter; 500 m. V/div M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 15

� Spark Detection Sparks detected by ammeter and we could hear the sound they produced M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 16

Calibrating the Ammeter to Improve its Offset M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 17

Test � Vin tested: 2 m. V, 5 m. V, 10 m. V, 500 m. V, 1 V, 5 V M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 18

� Magnifying first three cases(2 m. V, 5 m. V, 10 m. V): M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 19

ADC Characterization M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 20

Average ADC noise: 17. 5 n. A M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 21

Conclusions The noise produced by the ammeter connection is so low that it cant be measured (TGEM), this is important. Ø ADC (16 bits) The ADC has an internal noise of 11. 46 counts. Ø Ammeter resolution 3 n. A Ø M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 22

Future Work � Test the ammeter with the GEMs at Frankfurt. � Gain the project approval. M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 23

THANKS M. Sc. Javier Ruiseco Lopez, Taxco, Gro. Octubre 2015 24