F. E. Coffield

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The ETA-II linear induction accelerator is used to drive a microwave free-electron laser (FEL). Corkscrew motion, which previously limited performance, has been reduced by: (1) an improved pulse distribution system which reduces energy sweep, (2) improved magnetic alignment achieved with a stretched wire alignment technique (SWAT), and (3) a unique magnetic(More)
We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter(More)
Conclusions This study has sharpened the focus for future recirculator studies. Future system studies should include end-to-end optimization, including the performance of the target, so that the beam energy and the ion mass, charge state, and final velocity all become optimization variables. Collision cross-sections and sputtering rates were estimated here(More)
A digital phase comparator has been developed that is especially well suited to making precision phase measurements at high frequency. The circuit consists of two standard phase comparators that are interconnected so that their outputs are averaged to give the desired phase measurement. A clipping circuit consisting of back-to-back Schottky diodes is used(More)
A novel technique for the fabrication of binary-phase computer-generated reflection holograms is described. By use of integrated circuit technology, the holographic pattern is etched into a silicon wafer and then aluminum coated to make a reflection hologram. Because these holograms reflect virtually all the incident radiation, they may find application in(More)
Computer-generated, reflection holograms hold substantial promise as a means for performing complex machining, marking, scribing, welding, soldering, heat treating and other materials processing operations simultaneously and without motion of workpiece or laser beam. The use of holography for machining was first discussed by Moran. Computergenerated(More)
A flexible linear induction accelerator model (LIAM) was developed to predict both beam centroid position and the beam envelope. LIAM requires on-axis magnetic profiles and is designed to easily handle overlapping fields from multiple elements. Currently, LIAM includes solenoids, dipole steering magnets, and accelerating gaps. Other magnetic elements can be(More)
An expert system has been developed that acts as an intelligent assistant for tuning particle beam accelerators. This system is called MAESTRO-Model and Expert System Tuning Resource for Operators. MAESTRO maintains a knowledge base of the accelerator containing not only the interconnections of the beamline components, but also their physical attributes(More)
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