ORTEC DSPEC Pro, Hardware User Manual

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DSPEC Pro
®
Digital Gamma-Ray Spectrometer User’s Manual 794380D / 0914
46
Digital Filter Shaping-Time Constants
!
Rise time 0.8
µ
s to 23
µ
s in steps of 0.2
µ
s.
!
Flattop 0.3 to 2.4 in steps of 0.1
µ
s.
Dead-Time Correction Extended live-time correction according to Gedcke-Hale method.
Accuracy: area of reference peak changes <±3% from 0 to 50,000 cps.
Low-Frequency Rejector (LFR) When ON, removes low-frequency (<3 kHz) input noise
from spectrum.
Linearity
!
Integral Nonlinearity <±0.025% over top 99.5% of spectrum, measured with a mixed
source (
55
Fe at 5.9 keV to
88
Y at 1836 keV).
!
Differential Nonlinearity <±1% (measured with a BNC pulser and ramp generator).
System Temperature Coefficient
!
Gain <50 ppm/
E
C (typically <30 ppm/
E
C).
!
Offset <3 ppm/
E
C, with rise and fall times of 12
µ
s and flattop of 1
µ
s (similar to analog
6-
µ
s shaping).
Pulse Pileup Rejector Automatically set threshold. Pulse-pair resolution typically 500 ns.
Automatic Digital Pole-Zero Adjustment
3
Can be set automatically or manually. Remote
diagnostics via Insight Virtual Oscilloscope mode in MAESTRO.
Digital Gated Baseline Restorer Software-controlled adjustment of the restorer rate (Fast,
Slow, and Auto
4
).
ADC Gate (Not available for -PLUS [transistor-reset preamplifier] or SMART-1 detectors.)
Accepts a positive TTL input via the DIM’s “Inhibit” BNC. Signal must occur prior to and
extend 0.5
µ
s beyond peak detect. Software-selectable as off, coincidence, and anticoincidence.
LLD Digital lower-level discriminator set in channels. Hard cutoff of data in channels below
the LLD setting.
ULD Digital upper-level discriminator set in channels. Hard cutoff of data in channels above
the ULD setting.
Ratemeter Monitor the input count rate on the DSPEC Pro display or computer screen.