skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Enhanced neutron production from pyroelectric fusion

Abstract

The pyroelectric effect has been utilized as a means of producing x rays, electrons, positive ions, and neutrons. Pyroelectric sources have advantages over conventional sources, in that they are low cost, only consume a few watts of power, and are smaller than most sources. While pyroelectric x ray sources are already mature enough to be sold as commercial devices, the current generation of pyroelectric neutron sources is too low in intensity to be useful for commercial applications. This report demonstrates techniques which increase neutron production by a factor of 5.6 over previously published data.

Authors:
;  [1]
  1. Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)
Publication Date:
OSTI Identifier:
20971886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 90; Journal Issue: 17; Other Information: DOI: 10.1063/1.2731310; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CATIONS; ELECTRONS; NEUTRON SOURCES; NEUTRONS; PYROELECTRIC EFFECT; X RADIATION; X-RAY SOURCES

Citation Formats

Geuther, Jeffrey A., and Danon, Yaron. Enhanced neutron production from pyroelectric fusion. United States: N. p., 2007. Web. doi:10.1063/1.2731310.
Geuther, Jeffrey A., & Danon, Yaron. Enhanced neutron production from pyroelectric fusion. United States. doi:10.1063/1.2731310.
Geuther, Jeffrey A., and Danon, Yaron. Mon . "Enhanced neutron production from pyroelectric fusion". United States. doi:10.1063/1.2731310.
@article{osti_20971886,
title = {Enhanced neutron production from pyroelectric fusion},
author = {Geuther, Jeffrey A. and Danon, Yaron},
abstractNote = {The pyroelectric effect has been utilized as a means of producing x rays, electrons, positive ions, and neutrons. Pyroelectric sources have advantages over conventional sources, in that they are low cost, only consume a few watts of power, and are smaller than most sources. While pyroelectric x ray sources are already mature enough to be sold as commercial devices, the current generation of pyroelectric neutron sources is too low in intensity to be useful for commercial applications. This report demonstrates techniques which increase neutron production by a factor of 5.6 over previously published data.},
doi = {10.1063/1.2731310},
journal = {Applied Physics Letters},
number = 17,
volume = 90,
place = {United States},
year = {Mon Apr 23 00:00:00 EDT 2007},
month = {Mon Apr 23 00:00:00 EDT 2007}
}
  • The LLNL Crystal Driven Neutron Source is operational and has produced record ion currents of {approx}10 nA and neutron output of 1.9 ({+-}0.3) x 10{sup 5} per thermal cycle using a crystal heating rate of 0.2 C/s from 10 C to 110 C. A 3 cm diameter by 1 cm thick LiTaO{sub 3} crystal with a socket secured field emitter tip is thermally cycled with feedback control for ionization and acceleration of deuterons onto a deuterated target to produce D-D fusion neutrons. The entire crystal and temperature system is mounted on a bellows which allows movement of the crystal alongmore » the beam axis and is completely contained on a single small vacuum flange. The modular crystal assembly permitted experimental flexibility. Operationally, flashover breakdowns along the side of the crystal and poor emitter tip characteristics can limit the neutron source. The experimental neutron results extend earlier published work by increasing the ion current and pulse length significantly to achieve a factor-of-two higher neutron output per thermal cycle. These findings are reviewed along with details of the instrument.« less
  • The LLNL Crystal Driven Neutron Source is operational and has produced record ion currents of {approx}10 nA and neutron output of 1.9({+-}0.3)x10{sup 5} per thermal cycle using a crystal heating rate of 0.2 deg. C/s from 10 to 110 deg. C. A 3 cm diameter by 1 cm thick LiTaO{sub 3} crystal with a socket secured field emitter tip is thermally cycled with feedback control for ionization and acceleration of deuterons onto a deuterated target to produce D-D fusion neutrons. The entire crystal and temperature system is mounted on a bellows which allows movement of the crystal along the beammore » axis and is completely contained on a single small vacuum flange. The modular crystal assembly permitted experimental flexibility. Operationally, flashover breakdowns along the side of the crystal and poor emitter tip characteristics can limit the neutron source. The experimental neutron results extend earlier published work by increasing the ion current and pulse length significantly to achieve a factor-of-two higher neutron output per thermal cycle. These findings are reviewed along with details of the instrument.« less
  • We present evidence for the production of {sup 2}H(d,n){sup 3}He neutrons in gaseous deuterium by using a pyroelectric crystal as positive ion accelerator. In contrast to previous studies, neutrons were generated without a tip attached to the crystal and without using a solid deuterated target. The deuterium gas provided both the projectile and target nuclei. On the average, 1 neutron/s was obtained in our 'hot fusion' experimental setup. No neutrons were detected when a tip was used.
  • A palm sized, portable neutron source would be useful for widespread implementation of detection systems for shielded, special nuclear material. We present progress towards the development of the components for an ultracompact neutron generator using a pulsed, meso-scale field ionization source, a deuterated (or tritiated) titanium target driven by a negative high voltage lithium tantalate crystal. Neutron production from integrated tests using an ion source with a single, biased tungsten tip and a 3 Multiplication-Sign 1 cm, vacuum insulated crystal with a plastic deuterated target are presented. Component testing of the ion source with a single tip produces up tomore » 3 nA of current. Dielectric insulation of the lithium tantalate crystals appears to reduce flashover, which should improve the robustness. The field emission losses from a 3 cm diameter crystal with a plastic target and 6 cm diameter crystal with a metal target are compared.« less
  • Intense pulsed D-D neutron emission with rates >10{sup 10} n/s during the pulse, pulse widths of {approx}100's ns, and neutron yields >10 k per pulse are demonstrated in a compact pyroelectric accelerator. The accelerator consists of a small pyroelectric LiTaO{sub 3} crystal which provides the accelerating voltage and an independent compact spark plasma ion source. The crystal voltage versus temperature is characterized and compare well with theory. Results show neutron output per pulse that scales with voltage as V{approx}1.7. These neutron yields match a simple model of the system at low voltages but are lower than predicted at higher voltagesmore » due to charge losses not accounted for in the model. Interpretation of the data against modeling provides understanding of the accelerator and in general pyroelectric LiTaO{sub 3} crystals operated as charge limited negative high voltage targets. The findings overall serve as the proof-of-principle and basis for pyroelectric neutron generators that can be pulsed, giving peak neutron rates orders of magnitude greater than previous work, and notably increase the potential applications of pyroelectric based neutron generators.« less