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/Environmental Cosmic

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.

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 En (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 En (MeV) T 1/2 Yield (n/s)/ 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

Nuclear reactor neutrons are ~ 2 MeV plus thermal neutrons plus

moderated higher energy neutrons

Cf-252 has an energy similar to this at 2.35 MeV

The Jiddtek D-D Neutron Generator emits neutrons with similar

energies at ~ 2.45 MeV.

A Brief Overview

of

Neutron Sources

Intentional 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 2.35 MeV

D + 3H --> 4He3 + n 14.1 MeV

A Brief Overview

of

Neutron Sources

Intentional Neutron Generators A Metal Hydride Target is Utilized

After 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 Generator

Benefits:

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

Further Testing

A Jiddtek D-D neutron generator will be

evaluated at CSU, Fort Collins beginning

this December.

A team from LANL RP-SVS will

participate in that evaluation.

Further Testing

When the higher output D-D generator

becomes available that will be evaluated at

LANL RP-SVS.

The Jiddtek D-D generator will be used

along with RP-SVS’s AmBe and Cf-252

neutron sources to compare neutron energy

responses of a wide range of neutron

detectors

Neutron Generators

Credit for Table 1.1 and 1.2

Neutrons, Nuclei and Matter; An Exploration of

the physics of Slow Neutrons By James Byrne (1994)

Questions and Comments ?

Bob Goldstein, Technical Associates

tagold@nwc.net

WWW.TECH-ASSOCIATES.COM

818-883-7043