1. Digtal Pulse-Shape Analyzer Based on Multiple Constant-Fraction Time Intervals
Presented at 2016 IEEE Nuclear Science Symposium - N28-32
Valentin T. Jordanov
Yantel, LLC · Santa Fe, NM · USA

2. A New Concept for Pulse Shape Analysis – Front-End
PSD
SCINTILLATOR
DIGITAL
PSD
ADC 16 bit
125 MHz
HARDWARE
Simple but dedicated analog front-end electronics
Clock-event synchronization is not required
Works with fast scintillators with pulse shape discrimination capability
Can be used with PMT or other light readout devices
Implemented in a miniature, low power ( < 1W) portable device - nanoPSD

3. Neutron-Gamma Experimental Pulse Shapes - 125MHz ADC
STILBENE
1.25MeVee
350keVee
125keVee
33keVee

4. Principle of the New PSD Concept*
Ballistic
Deficit
Based on the gamma-neutron (alpha) difference due to the ballistic deficit in pulse heights
Measurement of time intervals between constant fraction points of the pulse amplitude
Amplitude independent measurement of multiple time intervals for a single pulse
*Patent Pending

5. Time Interval Linear Filter
Constant
Fraction
Discriminators
Pulse Shape Identifier
Constant Fraction Thresholds

6. Low Level Discriminator to Constant Fraction Time Intervals (LLD-CFD)
Simple algorithms, easy implementation
Real time operation
LLD must be set as close as possible to the base line
Timing issues with small amplitude pulses
Suitable for electron equivalent energies from 50keV to few MeV
Requires a separate pile- up rejector

7. LLD-CFD with Stilbene Detector Size: 35mmx31mm
Electron Equivalent Energy Range 200keV to 400keV
Figure of Merit 2.5; Neutron to Gamma Intensity 1:18
Electron Equivalent Energy Range 50keV to 200keV
Figure of Merit 1.9; Neutron to Gamma Intensity 1:22

8. LLD-CFD with Plastic Scintillator
Eljen EJ A; Detector Size: 25mmx25mm
Electron Equivalent Energy Range 50keV to 1.2MeV
Figure of Merit 2.0; Neutron to Gamma Intensity 1:12