Adrian, Marc

Last week we looked for evidence of crosstalk between PEM accelerometer channels in the PEM rack at the CS CER. We compared the crosstalk performance of channels which use an inductor versus a resistor by shaking a temporary accelerometer plugged into a permanent PEM channel at 25 Hz with a damped speaker. We find that there is no difference between the two configurations - the ratio of counts in the unexcited channels (i.e. possibly from crosstalk) to counts in the excited channel at 25, 50, 75 and 100 Hz range from O(1E-5) to O(1E-2). Attached are plots of ASDs of the CS accelerometers we tested during the tests as well as a file with the list of ASD ratios. The test were 5 minutes apiece, but the times given below used in our analysis are a little shorter - we want to build in some buffer time for us moving around after setting a test up.

Channel 1 Test Details:

Excited Channel: H1:PEM-CS_ACC_HAM6VAC_SEPTUM_Y_DQ

Start: 1367347574 (May 5, 2023 18:45:56 UTC)

End: 1367347744 (May 5, 2023 18:49:56 UTC)

Channel 16 Test Details:

Excited Channel: H1:PEM-CS_ACC_PSL_TABLE2_Z_DQ

Start: 1367347851 (May 5, 2023 18:50:33 UTC)

End: 1367348041 (May 5, 2023 18:50:56 UTC)