yesterday, according to Sophia's analysis, we changed TOHM
theresholds for 5C15-0, 5E06-1 and, due to an erroneous
handling, for 5W03-0.
We used the HP pulse generator to create negative 2mV test
pulses (12nsec width). Then, sending this signal to each inputs
of previous TOHM channels and using a scaler, we compared the
counts given by the trigger output of the pulse generator and
the TTL output of the TOHM channels. We regulated the trimmer
to obtain about 50% efficiency. This last operation was quite
difficult for 5C15-0 because very small trimmer variations
caused big efficiency changes.
Finally, we checked 100% efficiency when using 4mV pulses.
A successive test TOHM calibration showed a good behaviour
of these channels.
In addition, Sophia changed "via CAMAC" the theresholds
of following channels (new modules):
6T11-0, 6T11-1, 6T12-0, 6T15-0, 6T15-1 and 6T16-0.
A presto,
Ioannis, Roberto & Nicola