1. Nustar/crystal simulations 2006-10-03 genolini@ipno.in2p3.fr B. Genolini Crystal: CsI(Tl) (Saint Gobain), wrapped with reflector (VM2000, Tyveck?) Geometry: –[0]: 22 (h) × 22(w) × 22(l) mm –[A]: 22 (h) × 22(w) × 200(l) mm –[B]: 22 (h) × 44(w) × 200(l) mm –[C]: 22 (h) × 66(w) × 200(l) mm Particles:  (500 keV – 30 MeV) Tests: with (511 and) 662 keV Readout (on face w × h): –PMT ( Photonis 19 mm Ø, 15 mm PK Ø ) –APD ( square, 10 mm ) Goals: –Optimize the readout –Particle localization Questions –Energy resolution –Homogeneity Requirements for the simulation w h l CsI(Tl) Readout (PMT, APD) z y x   Injected with a source

2. Nustar/crystal simulations 2006-10-03 genolini@ipno.in2p3.fr B. Genolini 22  22  22 mm 3 crystal Single deposit: negligible (10 events/5235) Multiple deposit: 20426 (~4 per event) Large spectrum of energy deposit  high sensitivity to non uniformities and non linearities Injection with a source Simulations by T. Zerguerras: 10,000  injected

3. Nustar/crystal simulations 2006-10-03 genolini@ipno.in2p3.fr B. Genolini Crystal non linearity + non uniformity Non linear behavior at smaller energies Not negligible because: average energy deposit for an injection of 660 keV = 108 keV Contribution: 2.7 % FWHM @ 660 keV=1 % non uniformity + 2,3% non linearity 15 % Ref: 660 keV P. Dorenbos, J. T. M. de Haas, C. W. E. van Eijk, Non-proportionality in the Scintillation Response and Energy Resolution Obtainable with Scintillation Crystals, IEEE Trans. Nucl. Sci., vol. 42, pp. 2190-2202, 1995 W. Mengesha et al., Light Yield Nonproportionality of CsI(Tl), CsI(Na, and YAP, IEEE Trans. Nucl. Sci., vol. 45, pp. 456-461, 1998 2.7 %

4. Nustar/crystal simulations 2006-10-03 genolini@ipno.in2p3.fr B. Genolini Light collection – simulation principle Litrani (http://gentit.home.cern.ch/gentit/litrani) Database of GLAST: VM2000, CsI(Tl) (measured) Extend the database with Photonis and Hamamatsu data (quantum efficiencies) z y x Yield over a quarter of the volume (for 20 000 photons emitted), sum over 5 µs

5. Nustar/crystal simulations 2006-10-03 genolini@ipno.in2p3.fr B. Genolini Light collection - results (Depolished scintillator, VM2000, large PMT, green extended) PMT on the left Efficiency along the Z axis: mean over the X-Y plane More efficiency in the center as close to the edge: between 2 to 3 % 22×22×220 mm 22×44×200 mm 22×66×200 mm

6. Nustar/crystal simulations 2006-10-03 genolini@ipno.in2p3.fr B. Genolini Resolution calculation Hypothesis on the crystal gain non uniformity: 1 % In presence of electron/positron pairs, escape peaks are not taken into account for the energy resolution calculation

7. Nustar/crystal simulations 2006-10-03 genolini@ipno.in2p3.fr B. Genolini 22  22  220 mm 3 crystal / non polished / VM2000 / large PMT Resolution dominated by the collection non uniformity: –Crystal non linearity + non uniformity: 2.6 % FWHM –Efficiency non uniformity: < 5.5 % FWHM Comparison with measurements at 660 keV: –Simulation: 3000 photoelectrons, 8 % FWHM resolution –Measurement: 5500 photoelectrons, 6.7 % FWHM resolution Explanation of differences: –The PMT used for measurements has an excellent light yield –The "depolished" surface state is difficult to reproduce in simulations PMT at z = +110 mm