Team C - PMT (drafting)

Group members:

Mentor: Dr. Son Cao

Metal-package PMT module: H6780-1 / backup H10721-110 (newly purchased, using for O-BLM and for other research)

Three main objectives

PMT noise rate, raising, falling; PMT vs. siPM (quantum/detection efficiency, electric gain, linearity, dynamic range)
- Try to make light tightening as much as possible and measure the noise rate (without LED) at different thresholds.
- Use a pulsed optical LED with an optical fiber beam splitter to check the quantum/detection efficiency of PMT vs MPPC. For this you need to lowing down the light intensity as much as possible
- For dynamic range: try to gradually increase the light intensity and check when the signal starts saturated. Be caution to not increase the light amount rapidly
A concept of fast spectrometer: Get spectra of a white light source with optical filter and PMT
- Use white light LED and pulsing it at different voltage/
- Measurement (average acquisition) the signal amplitude with different optical filters (400nm, 455nm and 570nm)
  - Better to use fiber splitter with one signal is used to control the light source stability
Cosmic ray muons measurement (rate, light yield) with plastic scintillator cubes
- Estimate the rate of cosmic ray muon in the cube
- From that estimate the threshold needed for the rate of coincidence
- Check the spread of scintillation light induced by the mostly cosmic-ray muons

Using scintillator cube/ (1) one cube (2) two cube, one to read with PMTs, one to read with MPPC; for MPPC, one can use wavelength shifting fiber
How many photons are collected by MPPC/WLS and how many collected by PMT?

PMT voltage supply <15V and for gain control <1V
MPPC voltage supply <60V
- Some RF noise is induced by this voltage supply. If you are using PMT only, do not turn o this supply.
Light tightening is supper important for PMT (than for MPPC).
Be gentle when dealing with optical fibers
There is some electronic noise induced by other equipment/source in the room
- Estimate the rate
- Check the amplitude signal
- Some methods
  - Put higher threshold, also meaning that you will ignore events with low signal
  - Use light source from LED, you know when the light will come
  - Use coincidence technique when measuring with muons

Oscilloscope Siglent SDS1104X-E
Metal package PMT, model H6780-01
A box with SiPM https://www.hamamatsu.com/content/dam/hamamatsu-photonics/sites/documents/99_SALES_LIBRARY/ssd/s13360_series_kapd1052e.pdf. Students can solder a new one
DC power supplies for PMT and SiPM
Analog Discovery 2
Optical fiber beam splitter Thorlabs TT200R5F1A
Scintillator cube
White LED
Optical filters Thorlabs FGL400, FGL455, FGL570