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M. J. Burns - IEEE Xplore Author Profile

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Until 2003, the existing configuration of the Los Alamos Neutron Scattering Center (LANSCE) switchyard did not allow simultaneous delivery of the H−beam to Lines D and X. In the late 1990’ s, with increased activities in Areas B and C, which serve the ultracold neutron experiments (UCN) and proton radiography (pRad), respectively, planning began to increase beam availability to all areas by instal...Show More
The LANSCE (Los Alamos Neutron Science Center) control system upgrade program continues with the impending replacement of the RICE (Remote Instrumentation and Control Equipment) subsystem. The RICE subsystem upgrade is a challenge because of its technology (late 1960's), number of channels (>10,000), and unique characteristics (all-modules data takes, timed/flavored data takes). The plan is to rep...Show More
The Dual-Axis Radiographic Hydrodynamics Test (DARHT) facility will employ two perpendicular electron linear induction accelerators to produce intense, bremsstrahlung X-ray pulses for flash radiography. The first DARHT accelerator became operational in July 1999 producing a single electron beam pulse at 20 MeV, 2 kA, and 60 ns pulse. The second DARHT accelerator consists of a 18.4 MeV, 2 kA, 2 mic...Show More
The Dual-Axis Radiographic Hydrodynamics Test (DARHT) facility will employ two perpendicular electron linear induction accelerators to produce intense, bremsstrahlung X-ray pulses for flash radiography. We intend to produce measurements containing three-dimensional information with sub-millimeter spatial resolution of the interior features of very dense, explosively driven objects. The facility wi...Show More
The Dual-Axis Radiographic Hydrodynamics Test (DARHT) facility will use two perpendicular electron linear induction accelerators to produce intense, bremsstrahlung X-ray pulses for flash radiography. We intend to produce measurements containing 3D information with sub-millimeter spatial of the interior features of very dense explosively driven objects. The facility will be completed in two phases ...Show More
The PHERMEX (Pulsed High-Energy Radiographic Machine Emitting X-rays) standing-wave linear accelerator is a high- current electron beam generator used for flash-radiography. An improved electron gun has been designed employing a flat-thermionic cathode to replace the existing Pierce-geometry gun. The flat cathode yields increased current with the same applied voltage and cathode area as the Pierce...Show More
The mechanical and magnetic alignment of the first eight induction-cell, solenoid magnets of the Integrated Test Stand (ITS) for the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility were measured by observing the deflection of a fine, taut wire carrying a pulsed current. To achieve the required alignment (less than 0.25 mm offset and less than 5 mrad tilt), the magnet design uses quadrufi...Show More
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...Show More
The dual-axis radiographic hydrotest facility at Los Alamos National Laboratory will employ two linear induction accelerators to produce intense, bremsstrahlung X-ray pulses for flash radiography. The accelerator cell design for a 3-kA, 16-20-MeV, 60-ns flattop, high-brightness electron beam is presented. The cell is optimized for high-voltage stand-off while also minimizing the transverse impedan...Show More
The authors describe the results of wire measurements of several prototype DARHT cavities. The measurements reported cover MOD0 with ferrites removed, measurements with drive rods in place with various terminations, and measurements with compensation cans. Measured impedances are compared with AMDS code predictions. The effects of various rod terminations and compensation resistors on cavity imped...Show More
The linear induction accelerator focus magnet design for the Dual-Axis Radiographic Hydrotest (DARHT) facility is presented. Prototype solenoid magnets have demonstrated less than 1-mrad peak transverse error field while using large copper conductors. The design features multi-filar winding to reduce field errors due to winding geometry, iron rings within the solenoid to greatly reduce the effects...Show More
An induction line that will accelerate a 4-MeV, 3-kA beam of electrons to 16- to 20-MeV in 64 gaps is modeled. To suppress beam-breakup (BBU) instabilities induced by excitation of RF deflecting modes, the growth factor Gamma must be kept sufficiently small (e.g. <3). On prototype DARHT cavities, RF measurements have shown that the normally degenerate TM modes are split in frequency by the asymmet...Show More
An algorithm is described which rapidly finds a catalog of approximate transverse beam matching solutions. For a given initial beam, the algorithm finds the gradients of four quadrupole magnets so as to get four Twiss parameters (alpha and beta for horizontal and vertical planes) which are close to a set of desired values at the exit of a constant-energy beam line with no horizontal-vertical cross...
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As a part of the program in induction-linac free-electron laser research, the authors summarize the Laboratory's work in a variety of activities addressing the requirements imposed on wiggler systems. The development of improved designs is reported for DC iron-core electromagnetic wigglers to attain higher peak fields, greater tunability, and lower random-error levels. Specialized control systems ...Show More
The construction of a one-period wiggler system called a laced wiggler is presented along with test results from a prototype design. The laced electromagnetic wiggler is being developed to attain higher magnetic fields, shorter wavelengths, and larger gaps for the induction-linear accelerator, free-electron-laser (FEL) program. In the laced wiggler design, permanent magnets are located (laced) bet...
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A description is given of the design approach used for a permanent magnet-assisted electromagnet under development as part of the Induction Linac Free-Electron-Laser program. A single-period schematic of the wiggler is described. This device is an iron-core, DC electromagnet in which poles of identical magnetic scalar potential are attached to large iron plates. These scalar potential busses are b...Show More
Test Laboratory supports the ongoing development of the Induction Linac Free-Electron Laser and uses magnetic-field measurement systems that are useful in the testing of long-period magnetic structures, electron-beam transport magnets, and spectrometer magnets. The major systems are described which include two three-axis Hall probe-and-search coil transports with computer-controlled data acquisiti...Show More