NAPAC2019 - List of Keywords (site)

Paper	Title	Other Keywords	Page
MOYBB3	Progress in Nb₃Sn SRF Cavities at Cornell University	cavity, SRF, accelerating-gradient, superconductivity	37
	R.D. Porter, H. Hu, M. Liepe, N.A. Stilin, Z. Sun, M.J. Tao Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Niobium-3 Tin (NbSn) is the most promising alternative material for next-generation SRF cavities. The material can obtain high quality factors (> 10¹⁰) at 4.2 K and could theoretically support ~ 96 MV/m operation of a TESLA elliptical style cavity. Current Nb₃Sn cavities made at Cornell University achieve high quality factors but are limited to about 17 MV/m in CW operation due to the presence of a surface defect. Here we examine recent results on studying the quench mechanism and propose that surface roughness is a major limiter for accelerating gradients. Furthermore, we discuss recent work on reducing the surface roughness including chemical polishing, modification of material growth, and tin electroplating.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBB3
About •	paper received ※ 02 September 2019 paper accepted ※ 12 September 2019 issue date ※ 08 October 2019
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MOPLS06	Mu*STAR: An Accelerator-Driven Subcritical Modular Reactor	target, neutron, operation, SRF	163
	R.P. Johnson, R.J. Abrams, M.A. Cummings, T.J. Roberts Muons, Inc, Illinois, USA
	We present a conceptual design for a new modular, accelerator-driven subcritical reactor based on a molten salt. MuSTAR is a reactor, that without re-design, can burn a variety of nuclear fuels, with the beam tuned to that fuel. We will discuss the elements of this system: the accelerator, the reactor, the spallation target, and the fractional distillation to separate volatile fission products. Our GAIN project with ORNL is successfully completed, with a design of the Fuel Processing Plant that will convert spent nuclear fuel into the molten-salt fuel for MuSTAR.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLS06
About •	paper received ※ 01 September 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019
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WEPLM23	Updated Applications of Advanced Compact Accelerators	linac, electron, radiation, laser	694
	M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
	We are working for downsizing of RF accelerators from room-size to portable and table-top sizes and applying them to industril and social uses. We have developed portable 950 keV / 3.95 MeV X-band (9.3 GHz) electron linac based X-ray/neutron sources and successfully applied to on-site nondestructive inspection of industrial and social infrastructures such as chemical reaction chambers and bridges following the radiation safety law and regulation in Japan. By using the portable 950 keV / 3.95 MeV X-band electron linac based X-ray sources for on-site actual bridge inspection, we visualize inner reinforcement iron structure. The information of of the iron states is used for the structural analysis of the a bridge in order to evaluate its residual strength and sustainability. Table-topμelectron / ion beam sources using laser dielectric accelerating techniques are under development. The beam energy is ~ 1 MeV, the beam size is ~1 micron. We aim to apply them to 3D dynamic observation of radiation-induced DNA damage / repair for basic research of radiation therapy and low dose effect.
	Poster WEPLM23 [0.778 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM23
About •	paper received ※ 30 August 2019 paper accepted ※ 19 November 2019 issue date ※ 08 October 2019
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WEPLM50	Beam Driven Bimodal Cavity Structure for High Gradient Acceleration	cavity, simulation, bunching, acceleration	707
	X. Chang, Y. Jiang, S.V. Shchelkunov Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA J.L. Hirshfield Omega-P, Inc., New Haven, Connecticut, USA
	Funding: Supported by USA National Science Foundation, Award #1632588 Abstract: Research aiming to increase the RF breakdown threshold in electron/positron accelerators is being conducted at the Yale University Beam Physics Laboratory. Our two-beam accelerator approach employs a beam driven bimodal cavity structure. This cavity includes (i) two modes excited by the drive beam, with the higher mode frequency three times that of the fundamental TM010 mode; (ii) a low-current accelerated beam and high-current drive beam traversing the same cavity structure. This approach has the potential advantages of (a) operating at higher acceleration gradient with lower breakdown and pulsed heating rates than that of a single-mode cavity structure at the same acceleration gradient, due to the spatiotemporal field distribution properties in the bimodal cavities; and (b) obtaining high accelerating gradient with a low energy drive beam. Recent progress in simulations and work towards an experimental test stand is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM50
About •	paper received ※ 23 August 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOYBB3

Progress in Nb₃Sn SRF Cavities at Cornell University

cavity, SRF, accelerating-gradient, superconductivity

37

R.D. Porter, H. Hu, M. Liepe, N.A. Stilin, Z. Sun, M.J. Tao
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Niobium-3 Tin (NbSn) is the most promising alternative material for next-generation SRF cavities. The material can obtain high quality factors (> 10¹⁰) at 4.2 K and could theoretically support ~ 96 MV/m operation of a TESLA elliptical style cavity. Current Nb₃Sn cavities made at Cornell University achieve high quality factors but are limited to about 17 MV/m in CW operation due to the presence of a surface defect. Here we examine recent results on studying the quench mechanism and propose that surface roughness is a major limiter for accelerating gradients. Furthermore, we discuss recent work on reducing the surface roughness including chemical polishing, modification of material growth, and tin electroplating.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBB3

About •

paper received ※ 02 September 2019 paper accepted ※ 12 September 2019 issue date ※ 08 October 2019

Export •

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

MOPLS06

Mu*STAR: An Accelerator-Driven Subcritical Modular Reactor

target, neutron, operation, SRF

163

R.P. Johnson, R.J. Abrams, M.A. Cummings, T.J. Roberts
Muons, Inc, Illinois, USA

We present a conceptual design for a new modular, accelerator-driven subcritical reactor based on a molten salt. Mu*STAR is a reactor, that without re-design, can burn a variety of nuclear fuels, with the beam tuned to that fuel. We will discuss the elements of this system: the accelerator, the reactor, the spallation target, and the fractional distillation to separate volatile fission products. Our GAIN project with ORNL is successfully completed, with a design of the Fuel Processing Plant that will convert spent nuclear fuel into the molten-salt fuel for Mu*STAR.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLS06

About •

paper received ※ 01 September 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019

Export •

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

WEPLM23

Updated Applications of Advanced Compact Accelerators

linac, electron, radiation, laser

694

M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan

We are working for downsizing of RF accelerators from room-size to portable and table-top sizes and applying them to industril and social uses. We have developed portable 950 keV / 3.95 MeV X-band (9.3 GHz) electron linac based X-ray/neutron sources and successfully applied to on-site nondestructive inspection of industrial and social infrastructures such as chemical reaction chambers and bridges following the radiation safety law and regulation in Japan. By using the portable 950 keV / 3.95 MeV X-band electron linac based X-ray sources for on-site actual bridge inspection, we visualize inner reinforcement iron structure. The information of of the iron states is used for the structural analysis of the a bridge in order to evaluate its residual strength and sustainability. Table-topμelectron / ion beam sources using laser dielectric accelerating techniques are under development. The beam energy is ~ 1 MeV, the beam size is ~1 micron. We aim to apply them to 3D dynamic observation of radiation-induced DNA damage / repair for basic research of radiation therapy and low dose effect.

Poster WEPLM23 [0.778 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM23

About •

paper received ※ 30 August 2019 paper accepted ※ 19 November 2019 issue date ※ 08 October 2019

Export •

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

WEPLM50

Beam Driven Bimodal Cavity Structure for High Gradient Acceleration

cavity, simulation, bunching, acceleration

707

X. Chang, Y. Jiang, S.V. Shchelkunov
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
J.L. Hirshfield
Omega-P, Inc., New Haven, Connecticut, USA

Funding: Supported by USA National Science Foundation, Award #1632588
Abstract: Research aiming to increase the RF breakdown threshold in electron/positron accelerators is being conducted at the Yale University Beam Physics Laboratory. Our two-beam accelerator approach employs a beam driven bimodal cavity structure. This cavity includes (i) two modes excited by the drive beam, with the higher mode frequency three times that of the fundamental TM010 mode; (ii) a low-current accelerated beam and high-current drive beam traversing the same cavity structure. This approach has the potential advantages of (a) operating at higher acceleration gradient with lower breakdown and pulsed heating rates than that of a single-mode cavity structure at the same acceleration gradient, due to the spatiotemporal field distribution properties in the bimodal cavities; and (b) obtaining high accelerating gradient with a low energy drive beam. Recent progress in simulations and work towards an experimental test stand is presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM50

About •

paper received ※ 23 August 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019

Export •

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