PIXIE-4 User’s Manual
V2.69
©
XIA
2015. All rights reserved.
xiii
The advanced controls in this tab contain functions to modify the energy computation and to
acquire a series of measurements with varying filter settings and decay times to find the best
settings. For a detailed description of the filter operation, see section 6.
Figure 3.3:
The
Energy
tab of the P
ARAMETER
S
ETUP
Panel.
3.2.1.3 Waveform Tab
The
Waveform
tab contains the controls to set the length and pre-trigger delay of the waveforms
to be acquired. Advanced options include parameters for online pulse shape analysis
3.2.1.4 Gate Tab
The
Gate
tab contains the controls to set the window for gating acquisition with external
signals. We distinguish
-
GATE, a dedicated signal for each individual channel. It is active for the rising edge of
the pulse e.g. to suppress a detector pulse with a coincident pulse from a BGO shield.
-
VETO, a signal distributed to all modules and channels, but each channel is
individually enabled to require or ignore this signal. VETO is active during the
validation of a pulse (after pileup inspection), an energy filter rise time plus flat top
after the rising edge. With suitable external logic, the decision to veto a pulse can be
made from information obtained at the rising edge of the pulse (e.g. multiplicity from
several channels) and therefore this function is also called Global First Level Trigger
(GFLT).
For a detailed description of the GATE and VETO operation, see section 7.4.
3.2.1.5 Coincidence Tab
The
Coincidence
tab contains the controls to set the acceptable hit pattern, and the coincidence
window after validation during which channels can contribute to the hit pattern. There is a
checkbox for each possible hit pattern. For example, if the checkbox with pattern 0100 is
checked, events with a hit in channel 2 and no others are accepted. Selecting multiple
checkboxes accepts combinations of hit patterns, e.g. any event with exactly one channel hit.