Muon Efficiency

[cketter]

We need to understand trigger efficiency for the HI testbench. Thus far, no MIP signal has been observed in the pulse height spectra.

The following image illustrates the MIP peak we want to find.

[cketter]

We might consider some of the following ideas:

• Try collecting data at different HV settings and different trigger thresholds to look for this signal.
• Consider using a source to look for this signal
• Try connecting a second MPPC (S10362-013-050c) to the other side of the scintillator and look for coincidences between the two channels
  • Due to cabling constraints, this will require that the two channels come from different ASICs on the motherboard
• Try looking for coincidences using the SciFi tracker (smaller scintillators and higher-gain MPPC - S10362-11-100U) which has 150ch /10 ASICs instrumented already.

[cketter]

After discussion, we've agreed to pursue the third bullet point from above (instrumenting both sides of the scintillator with MPPCs and looking for coincidences in the two channels)

If we are unable to trigger two TargetX ASICs at the same time while using our existing firmware, then the short term solution will be to modify a few ribbon cables in order that both channels under test are routed into the same ASIC.

[RPeschke]

After mounting a second MPPD to the other end of the scintillator we are now able to trigger on real cosmic muons. With the help of the second scintillator we are now able to record a muon spectrum. We are using one MPPD as the active trigger channel and the other one (channel 14) as the passive channel.

Depending on the trigger settings on the first one the second channel should give us a spectrum of the deposit charge from the muon. The picture shows the two behaviors. The blue line is the (pseudo) random trigger the orange one is the muon spectrum.