Development of a Permanent-Magnet Microwave Ion Source for a Sealed-Tube Neutron Generator

Conference · Thu Mar 31 04:00:00 EDT 2011

OSTI ID:1022723

Waldmann, Ole; Ludewigt, Bernhard

A microwave ion source has been designed and constructed for use with a sealed-tube, high-yield neutron generator. When operated with a tritium-deuterium gas mixture the generator will be capable of producing 5*1011 n/s in non-proliferation applications. Microwave ion sources are well suited for such a device because they can produce high extracted beam currents with a high atomic fraction at low gas pressures of 0.2-0.3 Pa required for sealed tube operation. The magnetic field strength for achieving electron cyclotron resonance (ECR) condition, 87.5 mT at 2.45 GHz microwave frequency, was generated and shaped with permanent magnets surrounding the plasma chamber and a ferromagnetic plasma electrode. This approach resulted in a compact ion source that matches the neutron generator requirements. The needed proton-equivalent extracted beam current density of 40 mA/cm^2 was obtained at moderate microwave power levels of 400 W. Results on magnetic field design, pressure dependency and atomic fraction measured for different wall materials are presented.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Accelerator& Fusion Research Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1022723
• Report Number(s): LBNL-4641E
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
ACCELERATORS
BEAM CURRENTS
DESIGN
ELECTRON CYCLOTRON-RESONANCE
ION SOURCES
MAGNETIC FIELDS
MICROWAVE RADIATION
MIXTURES
NEUTRON GENERATORS
Neutron generator
Microwave ion source
Active interrogation
PERMANENT MAGNETS