There are two prefilter options. These are found in the main control window and can be activated separately.
The BGO filter applies BGO suppression to the target position Ge
channels.
This is either via an ADC for each BGO channels, or via a bit
in a pattern register.
The method used is chosen in the cluster setup window
by enabling either Phase1BGOAdcs or Phase1BGOPattern cluster types.
The filter accepts three parameters.
A Width parameter defines how far apart the Ge and BGO parameters can
be.
A Veto checkbox, which toggles getween marking and vetoing the
Ge channels with BGO associated.
A Fold parameter adds fold filtering. The fold is
counted using all Ge parameters falling inside the defined window
value.
This code is not executed if the fold value is less than 2.
There is also a checkbox to enable Ge pileup filtering. This marks the Ge Energy data word if a pileup record is found, and removes all the Ge pileup records from the data stream.
The prefilter throws away all "fast" channel data words which fall outside of the defined window immediately preceeding any "slow" parameter.
"Fast" and "slow" parameters are defined on a per cluster basis in the cluster template definition file.
This filter also executes Ge fold routines separately for outside and
inside the fast filter windows.
If the prefilter is defined,
then the Ge fold code is not executed in the BGO filter.
The filter accepts a Delay parameter which defines how many
clocks before the "slow" parameter, the window starts.
The window ends at the located "slow" parameter.