IPAC2018 - List of Authors (Buechler, C.E.)

Paper	Title	Page
MOPML052	The Path to Compact, Efficient Solid-State Transistor-Driven Accelerators	520
	D.C. Nguyen, C.E. Buechler, G.E. Dale, R.L. Fleming, M.A. Holloway, J.W. Lewellen, D. Patrick LANL, Los Alamos, New Mexico, USA V.A. Dolgashev, E.N. Jongewaard, E.A. Nanni, J. Neilson, A.V. Sy, S.G. Tantawi SLAC, Menlo Park, California, USA
	Funding: Research presented in this work is supported by (LANL) Laboratory Directed Research and Development 20170521ER and by (SLAC) Department of Energy contract DE-AC02-76SF00515. Small, lightweight, few-MeV electron accelerators that can operate with low-voltage power sources, e.g., solid-state transistors running on 50 VDC, instead of high-voltage klystrons, will provide a new tool to enhance existing applications of accelerators as well as to initiate new ones. Recent advances in gallium nitride (GaN) semiconductor technologies * have resulted in a new class of high-power RF solid-state devices called high-electron mobility transistors (HEMTs). These HEMTs are capable of generating a few hundred watts at S-, C- and X-bands at 10% duty factor. We have characterized a number of GaN HEMTs and verified they have suitable RF characteristics to power accelerator cavities *. We have measured energy gain as a function of RF power in a single low-beta C-band cavity. The HEMT powered RF accelerators will be compact and efficient, and they can operate off the low-voltage DC power buses or batteries. These all-solid-state accelerators are also more robust, less likely to fail, and are easier to maintain and operate. In this poster, we present the design of a low-beta, 5.1-GHz cavity and beam dynamics simulations showing continuous energy gain in a ten-cavity C-band prototype. See for example, http://www.wolfspeed.com/downloads/dl/file/id/463/product/174/cghv59350.pdf ** J.W. Lewellen et al., Proceedings of LINAC2016, Paper MO3A03
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML052
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THPAL023	Assessing the Continued Suitability of an Existing Water System for an Accelerator Upgrade	3673
	W.C. Barkley, C.E. Buechler, E.N. Pulliam LANL, Los Alamos, New Mexico, USA
	This paper assesses the continued suitability of an existing Water Cooling System (WCS) for cooling intermediate and high-power RF power amplifiers at the Los Alamos Neutron Science Center (LANSCE). At LANSCE, the high-power and intermediate power amplifiers installed in the 70s were at end-of-life with obsolete parts and no suitable replacements available to extend their life. The LANSCE Refurbishment Project was initiated (now complete) to replace these amplifiers and to utilize already existing WCSs. Two existing WCSs were repurposed and one new WCS was designed and installed. Unscheduled, intermittent water system trips on one of the WCSs has prompted the engineering group to drill down into the original decision, build a flow model and assess some of the legacy components' suitability to solve the problem. This paper discusses the general approach, troubleshooting and solution recommendations to be made for resolution of the intermittent issues.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL023
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THPMF090	Linac Design Elements for Spaceborne Accelerators	4291
	J.W. Lewellen, C.E. Buechler, G.E. Dale, M.A. Holloway, D.C. Nguyen, D. Patrick LANL, Los Alamos, New Mexico, USA V.A. Dolgashev, E.N. Jongewaard, J. Neilson, S.G. Tantawi SLAC, Menlo Park, California, USA J-.M. Lauenstein NASA Goddard Space Flight Center, Greenbelt, USA
	Funding: Los Alamos National Laboratory LDRD and Program Development Los Alamos National Laboratory, in collaboration with SLAC and Goddard Space Flight Center, have begun developing a high-duty-factor, MeV-range linear accelerator intended for use on satellites, specifically to probe the magnetosphere-ionosphere linkage. The design makes use of low-beta C-band cavities operating at moderate gradients, individually powered by 500-W RF amplifier chips. We present the current state of the design, and technology maturation efforts including RF amplifier performance studies, cavity tuner design and an initial acceleration test using a DC beam source and single RF cavity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF090
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Paper

Title

Page

The Path to Compact, Efficient Solid-State Transistor-Driven Accelerators

520

D.C. Nguyen, C.E. Buechler, G.E. Dale, R.L. Fleming, M.A. Holloway, J.W. Lewellen, D. Patrick
LANL, Los Alamos, New Mexico, USA
V.A. Dolgashev, E.N. Jongewaard, E.A. Nanni, J. Neilson, A.V. Sy, S.G. Tantawi
SLAC, Menlo Park, California, USA

Funding: Research presented in this work is supported by (LANL) Laboratory Directed Research and Development 20170521ER and by (SLAC) Department of Energy contract DE-AC02-76SF00515.
Small, lightweight, few-MeV electron accelerators that can operate with low-voltage power sources, e.g., solid-state transistors running on 50 VDC, instead of high-voltage klystrons, will provide a new tool to enhance existing applications of accelerators as well as to initiate new ones. Recent advances in gallium nitride (GaN) semiconductor technologies * have resulted in a new class of high-power RF solid-state devices called high-electron mobility transistors (HEMTs). These HEMTs are capable of generating a few hundred watts at S-, C- and X-bands at 10% duty factor. We have characterized a number of GaN HEMTs and verified they have suitable RF characteristics to power accelerator cavities **. We have measured energy gain as a function of RF power in a single low-beta C-band cavity. The HEMT powered RF accelerators will be compact and efficient, and they can operate off the low-voltage DC power buses or batteries. These all-solid-state accelerators are also more robust, less likely to fail, and are easier to maintain and operate. In this poster, we present the design of a low-beta, 5.1-GHz cavity and beam dynamics simulations showing continuous energy gain in a ten-cavity C-band prototype.
* See for example, http://www.wolfspeed.com/downloads/dl/file/id/463/product/174/cghv59350.pdf
** J.W. Lewellen et al., Proceedings of LINAC2016, Paper MO3A03

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML052

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAL023

Assessing the Continued Suitability of an Existing Water System for an Accelerator Upgrade

3673

W.C. Barkley, C.E. Buechler, E.N. Pulliam
LANL, Los Alamos, New Mexico, USA

This paper assesses the continued suitability of an existing Water Cooling System (WCS) for cooling intermediate and high-power RF power amplifiers at the Los Alamos Neutron Science Center (LANSCE). At LANSCE, the high-power and intermediate power amplifiers installed in the 70s were at end-of-life with obsolete parts and no suitable replacements available to extend their life. The LANSCE Refurbishment Project was initiated (now complete) to replace these amplifiers and to utilize already existing WCSs. Two existing WCSs were repurposed and one new WCS was designed and installed. Unscheduled, intermittent water system trips on one of the WCSs has prompted the engineering group to drill down into the original decision, build a flow model and assess some of the legacy components' suitability to solve the problem. This paper discusses the general approach, troubleshooting and solution recommendations to be made for resolution of the intermittent issues.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL023

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMF090

Linac Design Elements for Spaceborne Accelerators

4291

J.W. Lewellen, C.E. Buechler, G.E. Dale, M.A. Holloway, D.C. Nguyen, D. Patrick
LANL, Los Alamos, New Mexico, USA
V.A. Dolgashev, E.N. Jongewaard, J. Neilson, S.G. Tantawi
SLAC, Menlo Park, California, USA
J-.M. Lauenstein
NASA Goddard Space Flight Center, Greenbelt, USA

Funding: Los Alamos National Laboratory LDRD and Program Development
Los Alamos National Laboratory, in collaboration with SLAC and Goddard Space Flight Center, have begun developing a high-duty-factor, MeV-range linear accelerator intended for use on satellites, specifically to probe the magnetosphere-ionosphere linkage. The design makes use of low-beta C-band cavities operating at moderate gradients, individually powered by 500-W RF amplifier chips. We present the current state of the design, and technology maturation efforts including RF amplifier performance studies, cavity tuner design and an initial acceleration test using a DC beam source and single RF cavity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF090

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)