1. SUMMER INTERSHIP Electronics CERN BE-BI-BL Topic: photo-multiplier’s dynamic range improvements

2. DESIGN OF PM’s ELECTRICAL POWER SUPPLY

3. CONSTRAINTS 10 mA max signal (gaussian curve) Loading time of the system Maximum supplyable current

4. Capacitor Sizing Rd R11 C11 x X = max signal amplitude t = Pulse duration C > 100 Q/V C > [ 100 x*t*Rd+R11] / [(-Hv )*R11] t -Hv

5. Loading système constraints 1 ms t 100 ms5τ τ = R11*C11 < T / 2,5 2,5τ T 99% T=2,5τ Exp(-t/τ) > 0,99  τ < - t / ln(0,99) t = discharge time

6. Maximum supplyable current -Hv Imax Rd > (-Hv*R11) / (Imax*(R11+Rd))

7. Conclusion Rd > (-Hv*R11) / (Imax*(R11+Rd)) τ < - t / ln(0,99) τ = R11*C11 < T / 2,5 C > [ 100 x*t*Rd+R11] / [(-Hv )*R11] First results: - Rd=1MΩ - C=10μF