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Preliminary results from 2001 MDT test-beam

Preliminary results from 2001 MDT test-beam. Set-up. Results. Problems. Cosenza-Frascati-Pavia-Roma 1- Roma 3. Presented by P. Branchini. Status@Roma3. 1 MDT fully equipped. I < 100 nA. Gas Leak < 2mb/day. 12 mezzanines to read it. +1 to read the trigger. Average trigger rate from

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Preliminary results from 2001 MDT test-beam

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  1. Preliminary results from 2001 MDT test-beam • Set-up. • Results. • Problems. Cosenza-Frascati-Pavia-Roma 1- Roma 3 Presented by P. Branchini.

  2. Status@Roma3 • 1 MDT fully equipped. • I < 100 nA. • Gas Leak < 2mb/day. 12 mezzanines to read it. +1 to read the trigger. Average trigger rate from cosmic ray telescope 20 Hz

  3. IO/TDC Readout crate I O C P U T D C C S M CSM 4 ms Moreover Readout occurs through CSM.c lib (100 retries are possible) of course latest pals….although single trigger Multi trigger option is supported but not tested with latest pals.

  4. Results • More than 260000 events in 12 hours. • About 1000 reinitialization. • The number of reinitialization is • function of data size. We have many • since we have a huge noise (running • without faraday cage). • After the faraday cages installation (only read-out side for mechanical problems) we collected 300000 events with a few reinitializations (3!)

  5. SET-UP 1 BIL + 1 BML + 1 BOS chambers: a) All equipped with mezanine cards with the AMT-1 TDC read out with a CSM card. b) Read out system based on DAQ-1 with Rio2 processors and S-link c)DCS based on PVSS: monitor of temperature, gas flow and pressure 1 beam tracker: 2 coordinates on 48*48 tubes operated in streamer mode (not used for these preliminary results). 2 trigger systems: 1) 10*10 trigger on the beam core ~ 7000 evts per spill (1.4 KHz) 2) Hodoscope trigger on the beam halo ~ 10000 evts per spill (2 KHz)

  6. Most of data taken in the configuration: 1 BIL chamber on a platform which can be rotated by 40 degree. 1 BML chamber fixed on rails. 4 mezanine cards on each chamber (192 channels total) read out via the same CSM and the same adapter. 1 delivered adapter had 50% of the channels working.

  7. DAQ status. • Some DAQ problemssolved now: • Rate limited to ~ 100 Hz • now tested up to 4 kHz.. • Event de-synchronization (trackers vs MDT). • DAQ problem still to be investigated • automatic CSM re-initialization needed.

  8. Collected data BIL Angular Scan @ 0 Deg 800 Kevts BIL & BML Threshold Scan 900 Kevts BIL & BML HV Scan 600 Kevts BIL Angular scan @ 30 Deg 800 Kevts BIL Angular scan @ 3400 V 800 Kevts Hodoscope Runs 3000 kevtsData with no gas flow 1 day Data with “small” gas flow N days Baseline conditions: HV = 3080 V ( gain = 2x104) threshold = 60 mV ( 25th electron) gas mixture = Ar (97%) – CO2 (3%) pressure = 3 bar abs. gas flow = 300 N l / h

  9. Display events ‘no way’ to include this hit in the track without spoiling the C2. Smaller radius, d ray?

  10. Time distribution of the first hit in a single tube Noise = 1/(DT*Ntriggers)S n(i) (on the non-physical region)

  11. Threshlod scan. The risetime spans from 15 to about 30 ns.

  12. Time distribution study: T0 distribution in different mezzanines. Mezz 2 Mezz 1 Mezz 4 Mezz 3

  13. Time distribution study: Tmax-T0 distribution for the BIL tubes. RMS=2ns ns

  14. Distribution of noise frequency for the BIL and BML chambers. (HV on beam on)

  15. HV and thr scan studies.

  16. Autocalibration: Distribution is clean and well described by a gaussian around 0 All layers, layer 2 & 3 Band  10 mm 1 mm

  17. RT relation: BIL Multilayer 1 Undistinguishable in this scale! space (mm) time (ns) BIL Multilayer 2 space (mm) time (ns)

  18. Residual distribution after last iteration in Calib. r-slice = 1.5 mm r-slice = 6 mm r-slice = 11.5 mm r-slice = 13.5 mm All distributions are quite clean, rms very close to gaussian width. In the results which follow distribution of residuals in different slices was fitted with gauss+flat level. Width of distribution was taken to be s of gauss distribution

  19. How to get the resolution. If this hit was included in the track it would pull the track itself and would bias the resolution This hit is not included in the track drift time of excluded hit Track parameters using remaining hits (a,b,Da,…) d (distance of minimum approach)andextrapolation error Distribution of (d – drift) convolutes resolution and extrapolation error

  20. Resolution as a function of radius for different low voltage threshold.

  21. Quick and dirty. ‘Quick & dirty method’ The beam setup allows a simpler computation of space resolution. If track is orthogonal to the chamber drift times of tube in one layer is equal to the one of layer+2 sr(r)=1/2 vd(r) st(r) sr(r) = required space resolution vd(r) = drift velocity (as computed from tube time spectrum) st(r) = rms width of the difference 2 time measurements Quick & dirty method’ compared with CALIB and found to agree everywhere for at small and large radii

  22. HV scan quick and dirty method HV scan (threshold) Increase of the HV corresponds to an effective lowering of the threshold and gives better resolution mostly close to the wire

  23. Experimented problems Prom used: 8/22/01 At H8 the number of TDC header and trailer sometimes were not equal. Then the CSM stopped. The only way to get the system working was to reinitialize the CSM and TDCs once the DAQ stopped. Prom used: xC044 9/06-07 On this prom we could only make extensive test in the laboratory. It is possible to avoid the CSM to stop data taking when for some reason one TDC does not produce either an header or a trailer but after some time data become meaningles. Nevertheless the frequency of the problem is much reduced.

  24. How to reproduce the problem (to find a solution). In ROMA 3 we have a complete set-up with 18 mezzanines one adapter and a CSM with the latest PAL. To reproduce the problem once the set-up is loaded it is enough to initialize the electronics and deliver a software trigger to the CSM. Then read-back the data at the highest possible frequency. Two outcomes are possible: 1) After sometime the CSM will hang because a trailer from a TDC is missing. No-stop mode option has not been activated. 2) The system does not hang (No-stop mode option was activated) but after sometime data become meaningless.

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