Detector · · · · · · · · · · · · · · · · · · · Shaping (
µ
s)
Scintillation Photomultiplier [NaI(Tl)] · · · · 0.5, 1
Planar Implanted Passive Silicon (PIPS) · · · 0.5, 1, 2
Gas Proportional Counter· · · · · · · · · · · 0.5, 1, 2
Lithium Drifted Silicon [Si(Li)] · · · · · · · 6, 12
Lithium Drifted Germanium [Ge(Li)] · · · · 2, 4
Planar Germanium · · · · · · · · · · · · · · 4, 6, 12
Silicon Surface-Barrier (SSB) · · · · · · · · 0.5
Ultra-LEGe · · · · · · · · · · · · · · · · · · 0.125, 0.25, 0.5
Ge Array Detector · · · · · · · · · · · · · · 0.125, 0.25, 0.5
Refer to the specific Detector Operator’s Manual for the recommended shaping time.
This will be a good starting point. Further refinements may be realized through
experimentation. Collect spectra using shaping times above and below the
recommended to find the one that provides optimal resolution performance for your
particular detector and application.
Note
The P/Z matching must be recalibrated each time the shaping is changed.
Operation With Reset Preamps
The Model 2016 is fully compatible with most reset type preamps. These include the
Model 2101 Transistor Reset Preamp, the Model 2008 Optical Reset Preamp, and the
Model HRR High Rate Reset Preamp.
Reset preamps use an electronic circuit, as opposed to a feedback resistor to restore the
preamp output back to a reference level. As a result, the reset preamp output is a suc-
cession of step functions that staircase or ramp up to an upper limit that initiates a
preamp reset.
P/Z Compensation With Reset Preamps
Since the reset preamp signal does not have the characteristic exponential fall time of
RC preamps, pole/zero compensation is not required. When using the Model 2016
with a reset preamp, set the P/Z potentiometer to infinity, fully counterclockwise.
42
Performance Adjustments