PMT rate tests

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PMT Rate Tests

We work here with two PMT assemblies H10534MOD. With the second assembly having a modified base with an additional pre-amplifier powered by the applied HV.

Test with Reference PMT

We test the signal output of the Hamamatsu PMT assembly H10534MOD. This is based on a 10 stage tube with two outputs. The test are performed using a reference PMT assembly in a laser beam where the light output of the laser is adjusted to generate a signal in the reference PMT assembly that is similar to what is seen by the PMTs in the TOF paddle at 1550V operating voltage. One can clearly see that at 5MHz the signal is distorted as the PMT can not handle the increased current. At this point the current in the PMT increased by about 3uA from initially 253uA at 1kHz. At 2MHz the current was still at 253uA.

  • Reference PMT with laser output at 6.12
    • PMT HV 1550V 1kHz
      Pmt ref 1kHz 1550V.png
    • PMT HV 1550V 1kHz zoom
      Pmt ref 1kHz 1550V zoom.png
    • PMT HV 1300V 1kHz
      Pmt ref 1kHz 1300V.png
    • PMT HV 1300V 1kHz zoom
      Pmt ref 1kHz 1300V zoom.png
    • PMT HV 1300V 2MHz
      Pmt ref 2MHz 1300V.png
    • PMT HV 1300V 5MHz
      Pmt ref 5MHz 1300V.png
    • PMT HV 1300V 10MHz
      Pmt ref 10MHz 1300V.png

Test with Modified PMT base (preamp)

The modifications to the base are as follows: 2MOhm resistor between photo cathode and Dynode 7, 150kOhm resistor between dynode 7 and dynode 8 and a 420kOhm resistor parallele to the 1MOhm resistor that runs in series with a 2MOhm resistor but all in parallel with the capacitor of the last transitor stage.


  • Modified PMT with preamp and with laser output at 6.12
    • PMT HV 1300V 1kHz
      Pmt mod 1kHz 1300V.png
    • PMT HV 1100V 1kHz
      Pmt mod 1kHz 1100V.png
    • PMT HV 1100V 1kHz zoom
      Pmt mod 1kHz 1100V zoom.png
    • PMT HV 1100V 1MHz
      Pmt mod 1MHz 1100V.png
    • PMT HV 1100V 1MHz zoom
      Pmt mod 1MHz 1100V zoom.png
    • PMT HV 1100V 2MHz
      Pmt mod 2MHz 1100V.png
    • PMT HV 1100V 2MHz zoom Note the DC offset of +13mV
      Pmt mod 2MHz 1100V zoom.png
    • PMT HV 1100V 5MHz
      Pmt mod 5MHz 1100V.png
    • PMT HV 1100V 5MHz zoom Note the DC offset of +23mV
      Pmt mod 5MHz 1100V.png
    • PMT HV 1100V 10MHz
      Pmt mod 10MHz 1100V.png
    • PMT HV 1100V 10MHz zoom Note the DC offset of +23mV
      Pmt mod 10MHz 1100V zoom.png
    • PMT HV 1000V 10MHz
      Pmt mod 10MHz 1000Vnewtry.png
    • PMT HV 1000V 10MHz zoom Note DC offset of 18mV
      Pmt mod 10MHz 1000V zoomnewtry.png
    • PMT HV 1000V 100kHz
      Pmt mod 100kHz 1000V.png
    • PMT HV 1000V 100kHz zoom
      Pmt mod 100kHz 1000V zoom.png