1. Villa Olmo, Como 15-19 October 2001F.Giordano1 SiTRD R & D The Silicon-TRD: Beam Test Results M.Brigida a, C.Favuzzi a, P.Fusco a, F.Gargano a, N.Giglietto a, F.Giordano a, F.Loparco a M.N.Mazziotta a, M.Prest b, S. Raino’ a, P.Spinelli a, E.Vallazza b a Dipartimento di Fisica Università di Bari and INFN Sezione di Bari b INFN Sezione di Trieste

2. Villa Olmo, Como 15-19 October 2001F.Giordano2 Outline  Introduction  Beam Test Description  Data Analysis and Results  Monte Carlo Simulation  Conclusions SiTRD R & D

3. Villa Olmo, Como 15-19 October 2001F.Giordano3 SiTRD R & D Introduction Silicon strip detectors (SSD) with a few tenths of micron of pitch can be combined with a B field to separate the particles from photons in short distances i.e. Fabjan NIM 146 (77) 343 High Z gas detectors are typically used to detect TR X-rays Background = ionization energy loss of radiating particle Measurements were performed on the TR spectra using silicon diodes (Li- drifted): a magnetic field separates the radiating particle by TR photons and the Si detector is located a few meters downstream from the radiator

4. Villa Olmo, Como 15-19 October 2001F.Giordano4 SiTRD R & D y TRIGGER: e - : Pb Č 1 Č 2 S  - : Pb Č 1 Č 2 S Experimental Set-up (CERN-PS) x z x 50 cm30 cm y z Č1Č1 Č2Č2 S1S1 S2S2 S3S3 S4S4 Pb-Glass B  1T 5 cm C fibers radiator 15 cm Single Side Surface area: 3×3 cm 2 Thickness: 300  m Strip Pitch: 25  m Read-out Pitch: 50  m

5. Villa Olmo, Como 15-19 October 2001F.Giordano5 SiTRD R & D Experimental Set-up (Photos) The Cerenkov counters did not work properly during the data taking: no reliable rejection electron/pion analysis could be performed!

6. Villa Olmo, Como 15-19 October 2001F.Giordano6 SiTRD R & D The Magnet  B dl = 0.15 Tm Carbon Fiber Radiator B field longitudinal profile 15 cm Distance from centre B=1T Separation  3  4 Strips (Strip Pitch 50  m) Up to p=30 GeV/c

7. Villa Olmo, Como 15-19 October 2001F.Giordano7 SiTRD R & D SSD Noise evaluation  ped >  3.6 ADC ch (850 eV) S/N  100 TR Energy  10 keV X-rays search cut = 6  ped

8. Villa Olmo, Como 15-19 October 2001F.Giordano8 SiTRD R & D Cluster finding to take into account the charge sharing effect: 1.Search of a strip signal > 20  ped 2.Adjacent strips with signal > 10  ped Events with only one cluster per plane Evaluation of the particle direction by means of the upstream telescope Projection of the track on the downstream silicon wafer X-ray search: 1.Track shadow: ± 25 strips around the track projection 2. Looking for a signal > 6  ped within the shadow region Analysis strategies The  ped refers to single strip RMS pedestal

9. Villa Olmo, Como 15-19 October 2001F.Giordano9 SiTRD R & D 6  level 20  level SSD display X (cm) 0 50 75

10. Villa Olmo, Como 15-19 October 2001F.Giordano10 SiTRD R & D X-ray position respect to particle 1 GeV/c: 130 Strips 2 GeV/c: 65 Strips

11. Villa Olmo, Como 15-19 October 2001F.Giordano11 SiTRD R & D Energy Loss & Calibration The ADC channel distribution is fitted with a Landau function: the most probable value has been set to 80 keV (S. Hancock et al., Phys. Rev. A 28 (1983) 615) ADC channels Number of events Energy loss (keV)

12. Villa Olmo, Como 15-19 October 2001F.Giordano12 SiTRD R & D A run without radiator @ 2GeV/c 40 (~6%) ghost X-rays: noisy strips! 669 reconstructed charged particles

13. Villa Olmo, Como 15-19 October 2001F.Giordano13 SiTRD R & D X-ray Energy Spectra 1 GeV/c “electrons” 2 GeV/c “electrons” Background

14. Villa Olmo, Como 15-19 October 2001F.Giordano14 SiTRD R & D A Monte Carlo code has been developed to simulate the beam test set-up The MC is based on GEANT 3.21 and HEED The TR process has been included The electronics response has been also taken into account For more details see: “The Silicon-TRD: A Full Monte-Carlo Simulation” @ the Poster Session Full Monte Carlo simulation The simulated data has been analyzed using the same procedure as for real data

15. Villa Olmo, Como 15-19 October 2001F.Giordano15 SiTRD R & D 1 GeV/c 2 GeV/c X-ray Electron 1000 simulated events for each momentum MC results  Contamination  10 -3 @  e  60%

16. Villa Olmo, Como 15-19 October 2001F.Giordano16 SiTRD R & D Conclusions  A Silicon Strip Detector (SSD) combined with a magnetic field has been used to detect TR X-rays  A beam test has demonstrated the feasibility of the design  A full Monte Carlo code has been developed to validate the R&D  Further tests and analyses are needed to better study the detector performance