LHC Photomultiplier studies Emittance working group meeting 25022015

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LHC Photomultiplier studies Emittance working group meeting 25/02/2015 E. Piselli - J. Emery -

LHC Photomultiplier studies Emittance working group meeting 25/02/2015 E. Piselli - J. Emery - L. Timeo BE-BI-BL

Outline LHC photomultiplier Original system measurements Modifications and new measurements Conclusions 25/02/2015 E. Piselli

Outline LHC photomultiplier Original system measurements Modifications and new measurements Conclusions 25/02/2015 E. Piselli - J. Emery - L. Timeo 2

LHC photomultiplier PHILIPS XP 2243 B voltage divider phototube 25/02/2015 E. Piselli - J.

LHC photomultiplier PHILIPS XP 2243 B voltage divider phototube 25/02/2015 E. Piselli - J. Emery - L. Timeo 3

LHC photomultiplier PHILIPS XP 2243 B 25/02/2015 E. Piselli - J. Emery - L.

LHC photomultiplier PHILIPS XP 2243 B 25/02/2015 E. Piselli - J. Emery - L. Timeo 4

LHC photomultiplier PHILIPS XP 2243 B 25/02/2015 E. Piselli - J. Emery - L.

LHC photomultiplier PHILIPS XP 2243 B 25/02/2015 E. Piselli - J. Emery - L. Timeo 5

LHC photomultiplier K D 2 3 R R C 1 R=220 KΩ C 1=10

LHC photomultiplier K D 2 3 R R C 1 R=220 KΩ C 1=10 n. F C 2=112 n. F C 3=39 n. F 25/02/2015 D 1 D 3 R C 1 D 4 R D 5 D 6 A 1. 5 R 470 KΩ 680 KΩ C 1 C 1 C 2 C 2 C 3 Signal OUT 10 KΩ -HV E. Piselli - J. Emery - L. Timeo 6

Original system meaurements We have studied the response linearity of the photomultiplier. . .

Original system meaurements We have studied the response linearity of the photomultiplier. . . Visible saturation from measurements. . . 25/02/2015 E. Piselli - J. Emery - L. Timeo 7

Original system meaurements Lab setup Freq. generator 1 Hz Oscilloscope Green led diode A

Original system meaurements Lab setup Freq. generator 1 Hz Oscilloscope Green led diode A K Signal OUT 50Ω -HV 25/02/2015 E. Piselli - J. Emery - L. Timeo 8

Original system meaurements We have performed different measurements: • @ 1800 V and 2000

Original system meaurements We have performed different measurements: • @ 1800 V and 2000 V • @ different output current… 1 m. A, 2 m. A and 5 m. A • @ different pulse width… 500μs, 1 ms, 2 ms, 5 ms, 10 ms and 20 ms (always 1 Hz frequency) 2000 V 1 m. A 500μs σ=0. 08 mm 25/02/2015 2000 V 3 m. A 2 ms σ=0. 3 mm E. Piselli - J. Emery - L. Timeo 2000 V 5 m. A 5 ms σ=0. 8 mm 9

Modifications apported and new measurements Hamamatsu PMT specification in dynamic mode (ns scale): •

Modifications apported and new measurements Hamamatsu PMT specification in dynamic mode (ns scale): • To achieve 1% linearity Q*=100·Qsignal K A Qsignal We have hadded 3 decoupling capacitors (15μF each) in parallel to the 3 last ones in order to: • supply photomultiplier tube with an electric charge during the forming of the signal pulse • restrain the voltage drop between the last dynode and the anode 25/02/2015 E. Piselli - J. Emery - L. Timeo 10

Modifications apported and new measurements K D 2 3 R R C 1 R=220

Modifications apported and new measurements K D 2 3 R R C 1 R=220 KΩ C 1=10 n. F C 2=112 n. F C 3=39 n. F 25/02/2015 D 1 D 3 R C 1 D 4 R D 5 D 6 A 1. 5 R 470 KΩ 680 KΩ C 1 C 1 C 2 C 2 C 3 Signal OUT 10 KΩ -HV E. Piselli - J. Emery - L. Timeo 11

Modifications apported and new measurements K D 2 3 R R C 1 R=220

Modifications apported and new measurements K D 2 3 R R C 1 R=220 KΩ C 1=10 n. F C 2=112 n. F C 3=39 n. F 25/02/2015 D 1 D 3 R C 1 D 4 R D 5 D 6 A 1. 5 R 470 KΩ 680 KΩ C 1 C 1 C 2 C 2 C 3 C 4 C 4 Signal OUT 10 KΩ -HV C 4=15μF E. Piselli - J. Emery - L. Timeo 12

Modifications apported and new measurements 2000 V 1 m. A 500μs σ=0. 08 mm

Modifications apported and new measurements 2000 V 1 m. A 500μs σ=0. 08 mm 25/02/2015 2000 V 3 m. A 2 ms σ=0. 3 mm E. Piselli - J. Emery - L. Timeo 2000 V 5 m. A 5 ms σ=0. 8 mm 13

Conclusions B 1 and B 2 PM have been reinstalled in the machine… 25/02/2015

Conclusions B 1 and B 2 PM have been reinstalled in the machine… 25/02/2015 E. Piselli - J. Emery - L. Timeo 14

Conclusions We have few consequences after the modifications done to the system: • When

Conclusions We have few consequences after the modifications done to the system: • When HV is applied for the first time we have to wait about 30 sec • HV will be left ON after each scan at least for 30’ • Front end application software needs to be modified • New studies will be performed using laser diode and trying to simulate better the beam with PM response • We are investigating on new PM 25/02/2015 E. Piselli - J. Emery - L. Timeo 15

Thanks References: • Photomultiplier Tubes – Basic and Applications HAMAMATSU • “BWS Photomultipliers saturation,

Thanks References: • Photomultiplier Tubes – Basic and Applications HAMAMATSU • “BWS Photomultipliers saturation, hardware knowledge” 26. 09. 2012 - J. Emery • 25/02/2015 E. Piselli - J. Emery - L. Timeo 16