1 / 18

MRPC prototyping for NeuLAND and tests using the single electron mode of ELBE/Dresden

MRPC prototyping for NeuLAND and tests using the single electron mode of ELBE/Dresden. Dmitry Yakorev , Daniel Bemmerer, Zoltan Elekes, Mathias Kempe 1 , Daniel Stach and Andreas Wagner R3B Collaboration meeting on technical issues, Darmstadt 14.-16.04.2010.

corbin
Download Presentation

MRPC prototyping for NeuLAND and tests using the single electron mode of ELBE/Dresden

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. MRPC prototyping for NeuLAND and tests using the single electron mode of ELBE/Dresden Dmitry Yakorev, Daniel Bemmerer, Zoltan Elekes, Mathias Kempe1, Daniel Stach and Andreas Wagner R3B Collaboration meeting on technical issues, Darmstadt 14.-16.04.2010

  2. Some details on the prototypes (built at FZD and at GSI) Design questions addressed: • Number of gaps: 2x2, 2x3, 2x4 • Strip size: (1.2-2.5) x 40 cm • Glass thickness: 0.55/1.0 mm • Interstrip spacing: 0.3, 0.6, 1.6, 3 mm • Semiconductive materials: One side semiconductive mylar film, acrylic paint, Licron spray • Readout with impedance matching transformers • Single-ended and differential readout: FOPI, PADI, ALICE FEC.

  3. Experimental Cave Experimental setup, MRPC test station at ELBE/Dresden Measurement of time with reference to RF from ELBE linac, scintillators only for coincidence (trigger). MRPC can be moved remotely, 50cm in x and y direction

  4. MRPC detector tests at ELBE Dresden ELBE parameters used for our experiments: 1) Energy of electrons pc = 30 MeV 2) Repetition rate 13 MHz 3) Pulse width ~2 ps 4) “1 electron per bunch” mode. (U. Lehnert et al.), ~100 Hz Gate voltage 8.5 V mainly 1 electron per bunch Gate voltage 9.5 V 1-7 electrons per bunch Gate voltage ~6.5 V 1 electron per bunch Single electron mode. QDC spectra from plastic scintillator before MRPC unit to be tested.

  5. Effective size of single e- beam Horizontal scan Vertical scan 1.2cm * 20 cm/ns → σbeamsize = 60 ps

  6. 3 mm 2 σ 25 mm Cross-check: Time resolution of MRPC as a result of beam-spot size Time spectrum one side σraw = 4.3 ch → 108 ps Conclusion: Averaging of right and left side Is necessary to study “pure” time resolution (σraw2-σbeamsize2)1/2 = 90 ps After walk correction: σfinal = 95 ps

  7. Raw timing spectrum Walk Charge [1 Ch =25 fC] Time [ 1 Ch=25 ps ] Correction Time [ 1 Ch=25 ps ] Prototype tests at ELBE (by FZD and GSI groups, every 2 months). Walk-Correction procedure • Analysis procedure • Efficiency • Definition of event: we register signal from both ends of a target strip (strip where e- beam shoots). • We consider two neighboring strips because of the beam size. • Efficiency = (Number of RPC events) / (Number of trigger events) • Time Resolution • Calculation of position independent time value T=(t1+t2)/2, where t1 and t2 – TDC data from opposing ends of strip, relative to accelerator RF signal. • Walk correction by second + first order polynomial. • Quadratic subtraction of electronic noise: σEL ~ 25 - 35 ps Timing spectrum after correction for time walk,  ~ 90 ps

  8. One and the same strip read out on right+left side, main strip and crosstalk Right side:Main strip and crosstalk Left side:Main strip and crosstalk Charge [25 fC] Charge [25 fC] Time [25 ps] Time [25 ps] Charge [25 fC] Charge [25 fC]

  9. Time resolution, efficiency and cross-talk, 2x3 gap prototype TDC spectrum before and after walk-correction σEXP = 111 ps QDC spectrum

  10. Time resolution, efficiency and cross-talk, 2x2 gap prototype TDC spectrum before and after walk-correction σEXP = 102 ps QDC spectrum

  11. Comparison of different front-end electronics (2x2 gap prototype) PADI 2 FOPI FEE1

  12. Time resolution, efficiency and cross-talk (2x2 gap prototype) for different front-end electronics: FOPI, PADI & ALICE

  13. Time resolution and efficiency (2x2 gap prototype) for different front-end cards: FOPI, PADI & ALICE

  14. Time resolution and efficiency with and without transformers (1) Charge [25 fC] Charge [25 fC] Time [25 ps] Time [25 ps] Charge [25 fC] Charge [25 fC] With transformers Without transformers

  15. Time resolution and efficiency with and without transformers (2)

  16. Summary • Past and current activity • Efficiency for minimum-ionizing particles (experiments at ELBE) • Efficiency for 175 MeV quasi-monochromatic neutrons (experiment at TSL Uppsala) • Timing resolution of minimum-ionizing particles signals (experiments at ELBE) • Electrical and cosmic-ray measurements of detector performance. • Differential readout. Alice and PADI front-end cards • 2 x 2 = 4 gap structure seems to give satisfactory timing + MIP efficiency • Single-ended readout of central anode with FOPI FEE1 gives best results • Cross-talk level depends on interstrip spacing, ~10% level possible for ~1mm spacing • Impedance transformers don’t seem to significantly change the situation • Outlook • Continue ELBE tests • Development of “big” prototype, 2 x 0.5 m

  17. MRPC prototype developed and built at FZD: stack of glass plates

  18. Determine efficiency and time resolution of MRPC w/ electrons? • minimum-ionizing particles • MRPC operation can be studied independently from neutron conversion efficiency • time resolution is not dominated by reference detectors or reactions • caveat 1: low duty-cycle and high pile-up of conventional electron machines (DC or NC-RF) • caveat 2:convenient 103 e-/s correspond to a beam current of 1.6*10-16 A which is very hard to diagnose

More Related