Radioactive Source Measurements

Idea: Use a source from CERN TISS in order to simulate a 1MHz background rate on a single channel or pad.

Using an ²⁴¹Am and ⁹⁰Sr Source on the M2R2 Prototype, the count rate at given voltages was measured.

Cathode Pads, 8fC threshold, 2.6kV

⁹⁰Sr, 3.7MBq: 1.5kHz in 'close' double gap, 0.5kHz in 'far' double gap. At CERN one could get a Sr source with 262MBq which would bring this rate to 100kHz. This is still too low to use it as a 'background' test in the testbeams.

²⁴¹Am, 37MBq:  4kHz in 'close' double gap, 1.5kHz in 'far double gap. The maximum available at CERN is 357MBq  which brings the rate to 40kHz. Again, too low for us.