1. TRIPLEGEM and VFATs at The Test Beam Area TRIPLEGEM and VFATs at The Test Beam Area N. Turini……reporter Eraldo Oliveri! Eraldo Oliveri main worker! N. Turini……reporter Eraldo Oliveri! Eraldo Oliveri main worker! Totem collaboration meeting 7-3-2007

2. List of Tests -Stability Test The System at the end is stable (after a lot of pain….we removed an antistatic bag covering the DOHM hosting circuit, and everithing stabilzed!!!!). The measurements seem to be sufficiently reproducible. -noise Analysis tools Threshold Scan. Pulse Calibration Scan -VFATs noise Tests Hybrid V1 shows a different behavior than Hybrid V2. -High Voltage noise Studies Non float H.V. in a nearby NIM crate Floating power supply. Main noise improvements: -Very GOOD GND Connection of the Floating Power Supply to the MAIN GND near the detector -Remove the H.V.-READOUT GND Connection on Detector -Special GND connection between VFAT and GEM GND plane -VFATs on GEM Studies VFATs on strips in RUN mode introduce noise on Pads VFAT. Adding another VFAT on other pads seems to reduce the noise…to be investigated more accurately. We need to study at least half equipped detector. List of Tests -Stability Test The System at the end is stable (after a lot of pain….we removed an antistatic bag covering the DOHM hosting circuit, and everithing stabilzed!!!!). The measurements seem to be sufficiently reproducible. -noise Analysis tools Threshold Scan. Pulse Calibration Scan -VFATs noise Tests Hybrid V1 shows a different behavior than Hybrid V2. -High Voltage noise Studies Non float H.V. in a nearby NIM crate Floating power supply. Main noise improvements: -Very GOOD GND Connection of the Floating Power Supply to the MAIN GND near the detector -Remove the H.V.-READOUT GND Connection on Detector -Special GND connection between VFAT and GEM GND plane -VFATs on GEM Studies VFATs on strips in RUN mode introduce noise on Pads VFAT. Adding another VFAT on other pads seems to reduce the noise…to be investigated more accurately. We need to study at least half equipped detector.

3. VFAT C2F2 Noise Analysis Tools: Pulse Calibration Scan Check of the correlation between  erf function and pads capacitance to understand if the sigma of the erf fit is a good description of the noise

4. Noise Analysis Tools: Pulse Calibration Scan Noise vs Channels: The value of the noise for the smallest PAD. That is~ 5.335 Noise vs Channels: The value of the noise for the smallest PAD. That is~ 5.335 If we correlate the noise with the area of the pad we can do a linear fits. In first approximation the intercept could be associated to the “offset” noise due to the VFAT and to the connection on the readout foil. Fitting only on the large area pads, because large pad noise are less sensitive to readout foil noise, we get ~4.2 Count Units for Area=0. If we correlate the noise with the area of the pad we can do a linear fits. In first approximation the intercept could be associated to the “offset” noise due to the VFAT and to the connection on the readout foil. Fitting only on the large area pads, because large pad noise are less sensitive to readout foil noise, we get ~4.2 Count Units for Area=0. VFAT C2F2 not connected to Detector VFAT C2F2 connected to Detector (with special GND connection).

5. Noise Analysis Tools: Pulse Calibration Scan vs Threshold Scan Comparison between the data taken with threshold scan (MEAN Y and RMS Y at 5% and 1%) and the sigma of the erf Fit of the pulse calibration scan curve. A measure of the MEAN Y and RMS Y of all channel output of the threshold scan, reflects the behavior of the single channel pulse calibration scan. Comparison between the data taken with threshold scan (MEAN Y and RMS Y at 5% and 1%) and the sigma of the erf Fit of the pulse calibration scan curve. A measure of the MEAN Y and RMS Y of all channel output of the threshold scan, reflects the behavior of the single channel pulse calibration scan.

6. NO HV HV GROUNDED Reduction of noise with a better GND connection of the HV Power Supply near the detector HV-READOUT GND connection removed on the detector Special GND Connection on C2F2 YES NO YES Special GND Connection on C2F2 YES NO YES HV-READOUT GND connection NO YES NO HV-READOUT GND connection NO YES NO OFFOFF4kV4kV HV FILTER removed C2F2(Pads PS12) ON FAF3(Internal Strips) ON B0F2(External Strips) ON C2F2(Pads PS12) ON FAF3(Internal Strips) ON B0F2(External Strips) ON C2F2(Pads PS12) ON FAF3(Internal Strips) ON B0F2(External Strips) ON C272(Pads PS13) C2F2(Pads PS12) ON FAF3(Internal Strips) ON B0F2(External Strips) ON C272(Pads PS13) VFATsSTUDIES Noise Measurements vs Run #….…. C2F2(Pads PS12) ON & FAF3(Internal Strips) ON C2F2(Pads PS12) ON & FAF3(Internal Strips) ON C2F2(Pads PS12) ON HV FLOAT

7. Some Initial GND Loop VFAT SPECIAL GND CONNECTION H.V.-READOUT GND CONNECTION Cable to connect the H.V. Cable shield to the Table LV Power Supply TABLE TEST BEAM ZONE MAIN GND HV Filter GND from Control Room Through Trigger Line Floating H.V. Contact between filter box and table VFAT Control Room

8. H.V. GND Improvement C2F2 with FAF3 in Sleep Mode HV FLOATING CONNECTED + Standard CAEN Small Filter and TURNED ON to 10V and WITH THE FILTER BOX (gnd of H.V.) IN CONTACT WITH THE GND OF THE TABLE C2F2 with FAF3 in Sleep Mode HV FLOATING CONNECTED + Standard CAEN Small Filter and TURNED ON to 10V and WITH THE FILTER BOX (gnd of H.V.) IN CONTACT WITH THE GND OF THE TABLE C2F2 with FAF3 in Sleep Mode HV FLOATING CONNECTED + Standard CAEN Small Filter and TURNED ON to 10V C2F2 with FAF3 in Sleep Mode HV FLOATING CONNECTED + Standard CAEN Small Filter and TURNED ON to 10V and the shv shield in contact with the GND of of the table WITH A CABLE C2F2 with FAF3 in Sleep Mode HV FLOATING CONNECTED + Standard CAEN Small Filter and TURNED ON to 10V and the shv shield in contact with the GND of of the table WITH A CABLE C2F2 with FAF3 in Sleep Mode HV FLOATING CONNECTED + Standard CAEN Small Filter and TURNED ON to 10V and the shv shield in contact with the GND of of the table WITH A SHORT CABLE C2F2 with FAF3 in Sleep Mode HV FLOATING CONNECTED + Standard CAEN Small Filter and TURNED ON to 10V and the shv shield in contact with the GND of of the table WITH A SHORT CABLE C2F2 with FAF3 in Sleep Mode HV FLOATING CONNECTED + Standard CAEN Small Filter and TURNED ON to 10V and the shv shield in contact with the GND of of the table WITH A BIGGER CABLE C2F2 with FAF3 in Sleep Mode HV FLOATING CONNECTED + Standard CAEN Small Filter and TURNED ON to 10V and the shv shield in contact with the GND of of the table WITH A BIGGER CABLE

9. For the future…. -Hardware System Fix the Clock signal Fix trigger ground -Software tools Most of the useful plots and macros are implemented, need some more automatic scan macros. -noise Test Change of the Low Voltage Power Supply Cable. (And eventually test a local one). Study an half-equipped or totally–equipped TOTEM TripleGEM. Study of the definitive H.V. Power Supply. Check if we need others GND pin on the transition board near the device connectors to have a better GND connection with the VFAT with an additive GND cable between VFAT and transition board. For the future…. -Hardware System Fix the Clock signal Fix trigger ground -Software tools Most of the useful plots and macros are implemented, need some more automatic scan macros. -noise Test Change of the Low Voltage Power Supply Cable. (And eventually test a local one). Study an half-equipped or totally–equipped TOTEM TripleGEM. Study of the definitive H.V. Power Supply. Check if we need others GND pin on the transition board near the device connectors to have a better GND connection with the VFAT with an additive GND cable between VFAT and transition board.

10. TIME RESOLUTION OF THE TRIGGER SYGNALS and more…… -Hardware Read out of the trigger bits Put one trigger bit on a connector for time comparison with external trigger -Software Check single channel threshold setup before the test beam! TIME RESOLUTION OF THE TRIGGER SYGNALS and more…… -Hardware Read out of the trigger bits Put one trigger bit on a connector for time comparison with external trigger -Software Check single channel threshold setup before the test beam! The END