Post on 11-Jan-2016
Compact Neutron Generator Technology
Models: JNG-2-DD/DT &
JNG-3-DD/DT
---Robert Goldstein Technical Associates, North American Distributor
OVERHOFF TECHNOLOGY
A Brief Overview of
Neutron Sources
Naturally Occurring/EnvironmentalCosmic
The Solar Wind. High energy charged particles which hit nuclei
in the earth’s atmosphere creating secondary particles including neutrons. Intensity varies inversely with solar activity.
Terrestrial Spontaneous fission mostly U-238, less than 10% naturally
induced U-235 fission. 232 Cf
A Brief Overview of
Neutron Sources
Intentional Radioisotope sources Photoneutron Sources Accelerator sources Nuclear reactors Spallation sources Neutron generators
A Brief Overview of
Neutron Sources
Intentional Radioisotope sources
252 Cf SP ½ life 100yr, E(n) 2.3MeV
Table 1.1 Properties of commonly used (ũ,n) sources
Source Ea (MeV) T 1/2 Yield (n/a)
210Po+BE 5.30 138.4 days 0.7 x 10-4
226Ra+Be 4.78, 4.59 1.622 x 10 3 years 1.8 x 10-4
239Pu+Be 5.15 2.44 x 10 4 years 0.6 x 10-4
241Am+Be 5.48 4.60 x 10 2 years 0.7 x 10-4
242Cm+Be 6.11 163 days 1.1 x 10-4
241Am+B 5.48 2.44 x 10 4 years 1.0 x 10-5
241Am+F 5.48 2.44 x 10 4 years 4.0 x 10-6
A Brief Overview of
Neutron Sources
Intentional Photoneutron Sources
Table 1.2 Properties of commonly used photoneutron sources
Source E7 (MeV) T 1/2 Yield (n/β) cm 2 gm -1
24Na+Be 2.757 15.1 h 3.8 x 10-6
24Na+D2O 2.757 15.1 h 7.3 x 10-6
72Ga+D2O 2.51 14.3 h 1.9 x 10-6
124Sb+Be 1.691 60.9 days 5.1 x 10-6
140La+Be 2.51 40.2 h 0.08 x 10-6
Radioisotope decay with Gamma energy exceeding the neutron binding energy of a nucleus can eject a Be or D2 neutron, called a photo-neutron
A Brief Overview of
Neutron Sources
Intentional Accelerator Sources
The simplest way to use an accelerator to generate neutrons is to use the bremsstrahlung from electron accelerators such as synchrotron or beta tron to produce photoneutrons. This gives a continuous energy distribution which is not very useful.
Pulsed electron linacs can also be used, for example electron bombardment of Uranium can produce 30MeV neutrons.
A Brief Overview of
Neutron Sources
Intentional Nuclear reactors and Spallation sources
Are beyond the scope of this presentation.
A Brief Overview of
Neutron Sources
Intentional Neutron Generators
A subset of the accelerator category which are also fusion devices.
First used in 1933. These small electrostatic accelerators use one of two
exothermic reactions (produces energy): D + 2H --> 3He3 + n 3.26 MeV D + 3H --> 4He3 + n 17.6 MeV
A Brief Overview of
Neutron Sources
IntentionalNeutron Generators A Metal Hydride Target is UtilizedAfter the Reaction: The He and n travel in opposite directions producing high neutron yields. Energy at different angles is given by:
4En = En d +2(2 En Ed )1/2cos Θ = 3Q
JNG-2 – Neutron GeneratorBenefits:
Portability Reduced Power Input Requirements Increased Neutron Output Adaptable for Tailoring to Specific
Customer Needs. Reduced Manufacturing Costs High Reliability and Long Operating Life
Applications: Non-Destructive Testing
Homeland Security / Military Nuclear Industry Mining and Drilling Medicine Civil, Aeronautical, & Nautical Engineering Research Laboratories
Typical Target Based Neutron Generators versus JNG-2
Typical Neutron Generators JNG-2
Design Complicated with Many Electronic and Physical Components
Simple, mechanically based
Power Consumption Tens of Kilowatts 90 Watts
Neutron Output 10*6 n/s to 10*8 n/s at applied voltages in the range of hundred kV+
DD – 1*105 n/s
DT – 1*107 n/s
Case Diameter Varies 13 cm
Case Length Varies 65 cm
Weight 33 lbs – 362 lbs 28 lbs
Operation Deuterium – Deuterium – DD
Deuterium – Tritium - DT
Deuterium – Deuterium – DD
Deuterium – Tritium - DT
Projected Lifetime 1,200 hours – 4,000 hours 3-5 Years with Option to Refuel and Service at End Time
Neutron Generator – Basic Process
Homeland Security / Military
Detection of Explosives & Fissile Material in Cargo or Luggage
Chemical Analysis of Questionable Contents
Land Mine Detection Shipping Container Evaluation Narcotics Detection
Nuclear Industry
Compliance with the GALL Report
NUREG-1801 (2010)
Measuring Radiation Structural Damage
Containment Vessels
Cooling Pools
Pipes
Nuclear Industry
Generic Aging Lessons Learned (GALL)The GALL report evaluates existing programs for providing structural and component safety in Nuclear Power Plants. As these plants age and come up for renewal the GALL report facilitates the renewal process.
Its focus is on the staff review on the augmented existing programs for license renewal. Incorporation of the GALL report into NUREG-1800 and 1801 improves efficiency of the license renewal process.
Mining & Drilling
Oil Well Logging On-Line Assaying
of Materials i.e. Coal, Cement, etc
Borehole Logging Fuel Reprocessing Mining of a Wide
Variety of Minerals
Medicine Neutron
Radiography Neutron
Spectroscopy Neutron
Brachytherapy Boron Neutron
Capture Therapy (BNCT)
Civil, Aeronautical, & Nautical Engineering
Structural Inspection Gas & Oil Tank
Walls Bridge Integrity Airplane/Ship
Components Piping
Research Laboratories
Material Science
Nano Technology
Non-Invasive Analysis
Specifications for JNG-2 & JNG-3
JNG-2 DD & DT JNG-3 DD & DT
Neutron Output: 105 n/s using D-D
107 n/s using D-T
106 n/s using D-D
108 n/s using D-T
Neutron Energy 2.45 Mev using D-D
14 MeV using D-T
2.45 Mev using D-D
14 MeV using D-T
Cooling System Air Convection Air Convection
Voltage 45kV 65kV
Current 2mA 5mA
Power Consumption 90 W 325 W
Maximum Input Power 250 W 250 W
Length 65 cm 65 cm
Diameter 13 cm 13 cm
Total Weight 13 kg 13 kg
Projected Lifetime 3-5 Years with Option to Refuel and Service at End Time
3-5 Years with Option to Refuel and Service at End Time
Replaces Need for 252Cf Sources & Other Radioisotpe Sources
Safer to Operator Safer to the Public Eliminates Storage Issues of Source
Material No risk of theft of radioactive material
Additional Benefits of the
JNG-2 and JNG-3
Ideal for Calibrating Neutron Detectors for Spontaneous Fission Neutrons
Calibrate Neutron Detectors for Higher Energies Including AmBe when Energy Correction Factor is established
JNG-2-DT Produces 14.1 MeV Neutrons and is available as a Neutron Interrogator
Certification
This instrument has been tested and certified by independent university tests at
the University of Sydney, Australia
Neutron Generators
Table 1.1 and 1.2Neutrons, Nuclei and Matter; An Exploration of
the physics of Slow NeutronsBy James Byrne (1994)