Loading
 

DGF Applications


This guide is intended to help potential customers find the right XIA product for their application. This page includes the most common DGF/Pixie/Gamma applications.

Portable Gamma Spectroscopy (microDGF)

HPGe Clover Detectors for Physics Research

Segmented HPGe Detectors for Physics Research

Low Background Gamma Counting

Compton Background Suppression

Scintillator Fast Timing

Pulse Shape Analysis and Neutron-Gamma Discrimination

High Rate and High Resolution Gamma Spectroscopy Systems

Other Detectors



Portable Gamma Spectroscopy

In recent decades, portable gamma spectroscopy has come to supplement and even replace the traditional radiation monitor for many health physics and security applications. Knowledge of the isotopic composition of unknown radioactive material is key to identifying potential threats or hazards and distinguishing them from naturally occurring sources of radiation. Both semiconductor and scintillator detectors are used for this purpose. The versatile, low power and compact microDGF will work with essentially any type of preamplifier output signal, and is the natural solution for handheld and portable gamma detectors. Its low noise input and wide dynamic range gives state-of-the-art energy resolution even with HPGe detectors, (<0.14% at 1332 keV).

Click here for more information: microDGF Applications


HPGe Clover Detectors for Physics Research

The XIA Pixie family of multi-channel digital signal processors addresses many gamma spectroscopy applications in physics research and elsewhere. One example is the 4-element Clover detector, where four individual HPGe crystals are packaged close together in a common vacuum housing. The built-in timing circuitry of a 4-channel Pixie processor identifies coincident events between the individual detectors when gamma-rays are scattered from one crystal to another, and sums the energies to construct a spectrum with similar collection efficiency and peak-to-background to one large crystal. This "addback" feature can be used in any situation where coincident signals from multiple detectors (detector arrays) are to be identified and summed. As an alternative to the 4-channel module, 16-channel Pixie processors have been used when multiple Clover detectors are employed in a single experiment. In other multi-detector applications, custom coincidence/anti-coincidence logic can be set up across all channels.

Related publications:

"The DGF Pixie-4 spectrometer - Compact Digital Readout Electronics for HPGe Clover Detectors"
W. Hennig et al
NIM B 263 (2007) 175

"A high speed digital data acquisition system for the Indian National Gamma Array at Tata Institute of Fundamental Research"
R. Palit, S. Saha, J. Sethi, T. Trivedi, S. Sharma, B.S. Naidu, S. Jadhav, R. Donthi, P.B. Chavan, H. Tan, W. Hennig
NIM A 680, 11 (2012), p90-96

"Investigation of Exotic Nuclear Shapes and its Evolution using a Large Compton Suppressed Clover Array"
R. Palit
Proceedings of the DAE Symp.on Nucl. Phys. 55 (2010)


Segmented HPGe Detectors for Physics Research

Multiple contact segmented HPGe detectors are used in various physics research experiments, often to track interaction paths within the detector. In addition to collecting energy and timing information from each segment, the Pixie processors can store complete time-tagged preamplifier signal waveforms (up to tens of µs in length) for later off-line analysis. Furthermore, the Pixie processors' (user programmable) DSP can perform pulse shape analysis in real time to extract timing or position information or to differentiate between different classes of events based on the waveform shape. Selectable coincidence/anticoincidence settings for the detector segments can reduce the total data to be written to file. Custom coincidence/anti-coincidence logic may also be implemented depending on the requirements of the experiment. Configurable trigger settings allow capture of “spectator” signals from segments based on the trigger from a central core segment. In the case of the Segmented Germanium Array (SeGA) detector at the National Superconducting Cyclotron Laboratory (NSCL), 32-fold segmented HPGe detectors were instrumented using 16-channel Pixie modules.

Related publications:

"Real-time digital signal processor implementation of self-calibrating pulse-shape discriminator for high purity germanium"
R. Suarez et al
NIM A 586 (2008) 276

"Digital Pulse Processing: New Possibilities in Nuclear Spectroscopy"
W.K. Warburton et al
Applied Radiation and Isotopes 53, (2000) 913-920

"Digital Data Acquisition System for Experiments with Segmented Detectors at National Superconducting Cyclotron Laboratory"
K. Starosta, C. Vaman, D. Miller, P. Voss, D. Bazin, T. Glasmacher, H. Crawford, P. Mantica, H. Tan, W. Hennig, M. Walby, A. Fallu-Labruyere, J. Harris, D. Breus, P. Grudberg, W.K. Warburton
NIM A 610, p700-709, 2009


Low Background Gamma Counting

Low background gamma spectroscopy is an essential tool in health physics, nuclear waste management, and nuclear materials and weapons security. The use of low background detector materials and external shielding are important factors in improving the measurement sensitivity. But further improvements can be accomplished with electronic suppression using a Pixie signal processor, which can use a combination of analog (detector) and digital (gating) inputs to generate veto signals to remove unwanted background. In some cases, the Pixie's pulse shape analysis capability can also be used to identify background events and eliminate them from the spectrum. Beta/Gamma coincidence gating can be applied with multiple dedicated detectors or a single particle sensitive detector (e.g. phoswich), for example in applications of low level radioxenon detection.

Related publications:

"A gamma-gamma coincidence/anticoincidence spectrometer for low-level cosmogenic 22Na/7Be activity ratio measurement"
W. Zhang et al
Journal of Environmental Radioactivity, Volume 130, April 2014, Pages 1-6

"Improvements of low-level radioxenon detection sensitivity by a state-of-the art coincidence setup"
A. Cagniant et al
Applied Radiation and Isotopes Volume 87, May 2014, Pages 48-52

"Single Channel Beta-Gamma Coincidence Detection of Radioactive Xenon Using Digital Pulse Shape Analysis of Phoswich Detector Signals"
W.Hennig et al
IEEE Trans. Nucl, Sci, 53 (2006) 620

"Digital pulse-shape discrimination applied to an ultra-low background gas-proportional counting system: First results"
C.E Aalseth et al
Journal of Radioanalytical and Nuclear Chemistry , May 2013, Volume 296, Issue 2, pp 823-827


Compton Background Suppression

A variant of electronic suppression used for some low background detectors, Compton background suppression by electronic veto is a well-established technique for improving the peak-to-background ratio and the sensitivity of HPGe measurements, (whether low count rate or not). Typically, one or more scintillator detectors made from BGO or NaI surround the HPGe detector, and timing coincidence and logic circuitry is used to identify and veto simultaneous (Compton scattered) signals in the scintillator and HPGe detector. With the Pixie processors, a suite of several spectroscopy, timing and gating electronics modules can be replaced with a single 4-channel Pixie processor, which performs the signal recognition, pulse height measurement, timing and veto functions necessary for a complete Compton suppression system. An optional PDM module can generate logic pulses from a BGO shield to gate the analog inputs of a Pixie module, reducing the number of high performance digitizing channels in the system.

Related publications:

"A digital Compton suppression spectroscopy without gamma-ray coincidence-summing loss using list-mode multispectral data acquisition"
W. Zhang et al
Journal of Radioanalytical and Nuclear Chemistry June 2012, Volume 292, Issue 3, pp 1265-1272

"Improvements of low-level radioxenon detection sensitivity by a state-of-the art coincidence setup"
A. Cagniant et al
Applied Radiation and Isotopes Volume 87, May 2014, Pages 48-52

"Single Channel Beta-Gamma Coincidence Detection of Radioactive Xenon Using Digital Pulse Shape Analysis of Phoswich Detector Signals"
W.Hennig et al
IEEE Trans. Nucl, Sci, 53 (2006) 620

"Digital pulse-shape discrimination applied to an ultra-low background gas-proportional counting system: First results"
C.E Aalseth et al
Journal of Radioanalytical and Nuclear Chemistry , May 2013, Volume 296, Issue 2, pp 823-827


Scintillator Fast Timing

The Pixie processors offer digitization rates up to 500 MSPS and Constant Fraction timing with resolutions in the tens to hundreds of picoseconds. These specifications are well suited for working with fast scintillators for time of flight measurements. One such example is the Versatile Array of Neutron Detectors at Low Energy (VANDLE), which utilizes an array with a large number (100+) of plastic scintillator bars for neutron Time-of-Flight measurements. In this experiment, 16-channel Pixie processors have demonstrated sub-nanosec timing resolution, limited only by the PMT and scintillator noise and jitter. The Pixie's sophisticated signal recognition and coincidence logic increases the system's live-time to over 99%. Another example is associated particle imaging (API), where correlated alphas and gammas are used to determine direction, distance, and composition of a target. In neutron activation analysis (NAA), prompt and delayed events can be acquired into separate spectra.

Related publications:

"Development of 500 MHz Multi-Channel Readout Electronics for Fast Radiation Detectors"

"Optimization of the National Superconducting Cyclotron Laboratory Digital Data Acquisition System for Use with Fast Scintillator Detectors"
C.J. Prokop et al
NIMA, 792, 81 (2015)

"Digital data acquisition system implementation at the National Superconducting Cyclotron Laboratory"
C.J. Prokop et al
Nucl. Instrum. Meth. in Phys. Res. A, 741, 163 (2014)

"A Digital Spectrometer Approach to Obtaining Multiple Time-Resolved Gamma-Ray Spectra for Pulsed Spectroscopy"

"Time Resolution Studies using Digital Constant Fraction Discrimination"

"A Fast Pulsed Neutron Source for Time-of-Flight Detection of Nuclear Materials and Explosives"
Paulauskas, S. V.; Madurga, M.; Grzywacz, R.; Miller, D.; Padgett, S.; Tan, H.

"A digital data acquisition framework for the Versatile Array of Neutron Detectors at Low Energy (VANDLE)"
NIM A Volume 737 (2014), Pages 22-28


Pulse Shape Analysis and Neutron-Gamma Discrimination

For detectors sensitive to different types of radiation (e.g. Stilbene, CLYC, Xylene, EJ-309), the pulse shape analysis (PSA) option of a Pixie processor allows real-time pulse shape discrimination (PSD) of gammas, alphas, betas or neutrons in mixed field radiation. It can be combined with Time-of-Flight separation e.g. for localization of the target. For phoswich detectors, interactions in different layers of the detector can be distinguished, and the energy deposited in each layer can be measured, then binned both into separate spectra and into E1-vs-E2 histograms in on-board memory.

Related publications:

"CLYC versus Stilbene: Optimization and comparison of two neutron-gamma discriminating scintillators"

"Particle Identification in CsI(Tl) Crystal Using Digital Pulse Shape Analysis"

"Radioxenon Measurements with the PhosWatch Detector System "

"Single Channel Beta-Gamma Coincidence Detection of Radioactive Xenon Using Digital Pulse Shape Analysis of Phoswich Detector Signals"

"Digital Pulse Shape Analysis with PHOSWICH Detectors to Simplify Coincidence Measurements of Radioactive Xenon"

"Pulse Shape Analysis with the Pixie-500e"


High Rate and High Resolution Gamma Spectroscopy Systems

There are some applications where gamma-ray count rates are high (>100 kcps) by necessity or design. One such case is the assay of spent nuclear fuel and other special nuclear materials by gamma-ray spectroscopy, which is an important element of the nuclear safeguards program. For the accurate assay of plutonium in spent nuclear fuel, a relatively weak Pu peak must be detected in the presence of a high gamma background from decaying fission products. To address this challenge, multi-contact HPGe detectors are being developed that provide both high resolution and high count rate capability. For this and similar applications, the Pixie modules provide the required multi-channel high resolution signal processing with output count rates approaching 1 Mcps. In some cases, custom logic may be incorporated for special real-time data handling requirements.


Other Detector Applications

There are many ground-breaking and novel detector concepts under development for various applications in physics research, medicine, and elsewhere, which can take advantage of the unique high resolution, fast timing, or high throughput features of the Pixie pulse processors. In another development, Pixie processors were used for sub-nanosec timing coincidence and signal waveform storage in a prototype array of proton sensitive scintillating fibers, with the goal of imaging patient treatment areas during proton cancer therapy. A third example is the contribution of the Pixie-16 in the search for Super Heavy Elements. Here, a double-sided silicon strip detector is used to capture very short lived <1 Ás) alpha particle decays from super heavy elements. In the search for element Z=120, the fast multi-channel signal processing and waveform capture feature of the Pixie has been successfully deployed to measure alpha decays within 100 ns of the initiating event.

Related publications:

"Digital acquisition system for superheavy experiments"
David Miller et al
APS Bulletin, 2011 Fall meeting of the APS Division of Nuclear Physics. Vol 56, No 12

"Digital signal processing for superheavy element studies"
D. Miller, K. Miernik, D. Ackermann, R. Grzywacz, S. Heinz, F. P. He▀berger, S. Hofmann, J. Maurer, K. Rykaczewski, and H. Tan
GSI Annual Report 2011, p. 220, PHN-NUSTAR-SHE-16

"High efficiency beta-decay spectroscopy using a planar germanium double-sided strip detector"
N. Larson et al
Nucl. Instrum. Meth. in Phys. Res. A, 727, 59 (2013)


Portable Gamma Spectroscopy

In recent decades, portable gamma spectroscopy has been come to supplement and even replace the traditional radiation monitor for many health physics and security applications. Knowledge of the isotopic composition of unknown radioactive material is key to identifying potential threats or hazards and distinguishing them from naturally occurring sources of radiation. Both semiconductor and scintillator detectors are used for this purpose. The versatile, low power and compact microDXP will work with essentially any type of preamplifier output signal, and is the natural solution for handheld and portable gamma detectors. Its low noise input and wide dynamic range gives state-of-the-art energy resolution even with HPGe detectors, (<0.14% at 1332 keV).

Click here for more information: microDXP Applications


XIA Home > Products > DGF Products > DGF_Applications

Back to top of this page | Back to XIA home page.

http://www.xia.com/DGF_Applications.html, last updated January 24, 2017
© XIA LLC 2016