The diamond detector has tended to increase in rate when it is hot (peaking late afternoon) and decreasing when it is cold (with a minimum just before sun-rise). Some of the rate could therefore be temperature dependent noise levels rising above the trigger threshold.
We are currently triggering around 70mV, far below the peak signal value of 1.4V (by about a factor of 20). While we cannot expect to see most of them at the peak value because of poor resolution and potentially different particle energies, we should expect the vast majority of real heavy-ion signals to fall above 1/4 of the peak height. When we go into the vault on Tuesday, we should therefore raise the thresholds by about a factor of 5, to see whether this stabilises the rate.
Irrespective of this, with the beam deposited so far from the detector as is the case, we should only see halo and/or reaction products, and we would not be able to use this as a beam intensity monitor, irrespective of performance. At best as a beam-quality monitor. |