Advanced Photodetectors CERN , LNF, Photonis , PSI; ER: 2 yrs (contact person: C. Joram, CERN)

1. Advanced Photodetectors • CERN, LNF, Photonis, PSI; ER: 2 yrs (contact person: C. Joram, CERN) • Development and application of novel photodetectors. • The development of novel photodetectors like Hybrid Photodetectors (HPD) and Geiger-mode Avalanche Photodiodes (G-APD), pursued during the past years in close collaboration with industry, led to exciting perspectives for applications ranging from particle physics (e.g. calorimetry, particle identification, tracking using scintillating fibres) to astro-particle physics and medical imaging. The ongoing development program covers concept, design, construction and performance evaluation of various photodetectors. Most of the work is done in close collaboration with the industrial partner Photonis. • The project comprises 3 lines of activities: • Integration of an X-HPD in a pressure sphere and measure performance under water. • (2) Design, construction and test of a scintillating fibre tracker module for ATLAS with G-APD readout. Test of a prototype of a highly granular lead-scintillating fibre or tile-wave­length shifter calorimeter readout with G-APDs at the Frascati Test Beam facility. • (3) In collaboration with PSI: Test of a positron emission tomography(PET) camera based on long axially oriented crystals with wavelength shifter strip readout with G-APDs. • The ER will be trained on advanced photodetector design, qualification and applications. He/she will spend several months at our industrial partner Photonis and participate in beam (at Frascati) and possibly phantom tests (PET project).

2. T ~ 0.4 QE QE X-HPD Concept of a spherical Hybrid Photo Detector with central spacial crystal (X-tal) anode Possible applications: water (ice) based neutrino detectors (based on Cherenkov effect). • Radial electric field • negligible transit time spread • ~100% collection efficiency • no magnetic shielding required • Large viewing angle (dW ~ 3p) • Possibility of anode segmentation • imaging capability (limited!) • Sensitivity gain through • ‘Double-cathode effect’  QEmax ~ 50% observed. A. Braem, NIM A 581, (2007), 469-472. Proceedings of VLVNT08 and NDIP 08 conferences, under publication in NIM A. 2

3. X-HPD ½ scale prototype (208 mm Ø) with conical LYSO crystal (PC120) LYSO 12 Ø × 18 mm 3

4. X-HPD (PC120) Full production at CERN, supported by Photonis 4 4

5. ER Project: Rebuild a new X-HPD, integrate it in a pressure sphere and test it in a water tank with cosmic rays. m C-light OM in water tank Test set-up available at INFN Genova (M. Taiuti) m q can be rotated wrt. Euler angles in the water tank. 17” Pressure sphere (from Antares) with special Genova PMT tube. 5

6. ATLAS ALFA 64-ch. MAPMT tube (X 23) Scint. fibre tracking detectors

7. Alternative readout device: Geiger mode APD = SiPM • Compact • Higher QE • Nice signal definition (photon counting) ~ 10 p.e. (single sided readout) Hamamatsu G-APD (MPPC) S10362-11, connected to an ALFA fibre, exposed to a Sr-90 source. Fit = P(m)  G(mi,si) not perfect! Sr-90 is not mono-energetic. Sr-90 PMT (Trigger)

8. AX-PET Conventional PET geometry Axial PET geometry

9. Readout of long (LYSO) scintillator crystals with G-APDs. Extraction of the longitudinal coordinate by a set of WLS strips. Hardware, electronics, DAQ for 2 camera heads developed/procured. Mechanics being assembled.

10. Simulation and reconstruction software being developed / optimized Performance tests with sources and phantoms foreseen in Michigan and/or Zurich. ER Project: In collaboration with PSI: Test of a positron emission tomography (PET) camera based on long axially oriented crystals with wavelength shifter strip readout with G-APDs.

11. • P7-M1 • P7-D1 • P7-D2 • P7-M2 • P7-D3