Technology demonstration for the DARHT Linear Induction Accelerators
The Dual-Axis Radiographic Hydrodynamics Test (DARHT) facility will employ two 16-MeV, 3-kA Linear Induction Accelerators to produce intense, bremsstrahlung x-ray pulses for flash radiography. Technology demonstration of the key accelerator sub-systems is underway at the DARHT Integrated Test Stand (ITS), which will produce a 6-MeV, 3-kA, 60-ns flattop electron beam. We will summarize measurements of ITS injector, pulsed-power, and accelerator cell performance. Time-resolved measurements of the electron beam parameters will also be presented. These measurements indicate that the DARHT accelerator design is sufficiently advanced to provide the high quality electron beams required for radiography with sub-millimeter spatial resolution.
10-MeV linear induction accelerator for flash radiography
A 10 MeV linear induction accelerator has been built for use in flash radiography. This machine consists of a 1 MeV injector followed by 28 accelerating induction cells. Each accelerating cell adds 320 kV to the electron beam. An electron beam of 2 kA with focal spot diameter < 4 mm on the target has been obtained. Exposure dose at a distance of 1 meter is 90 R, and the pulse length is 90 ns. In this paper the construction of the accelerator and its operation characteristics are presented.
Electron-beam generation, transport, and transverse oscillation experiments using the REX injector
The REX machine at LANL (Los Alamos National Laboratory) is being used as a prototype to generate a 4-MV, 4.5-kA, 55-ns flat-top electron beam as a source for injection into a linear induction accelerator of the 16-MeV dual-axis radiographic hydrotest facility. The pulsed-power source drives a planar velvet cathode producing a beam that is accelerated through a foilless anode aperture and transported by an air core magnetic lens for injection into the first of 48 linear induction cells. Extensive measurements of the time-resolved (<1-ns) properties of the beam using a streak camera and high-speed electronic diagnostics have been made. These parameters include beam current, voltage, current density, emittance, and transverse beam motion. The effective cathode temperature is 117 eV, corresponding to a Lapostolle emittance of 0.96 mm-rad.<<ETX>>