IPAC2015 - List of Keywords (accelerating-gradient)

Paper	Title	Other Keywords	Page
MOPJE081	Longitudinal Stability in Multi-Harmonic Accelerating Cavities	cavity, acceleration, cathode, controls	506
	R.M. Jones, L.R. Carver UMAN, Manchester, United Kingdom J.L. Hirshfield Yale University, Physics Department, New Haven, CT, USA Y. Jiang Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
	Accelerating cavities that excite multiple modes at integer harmonics of the fundamental frequency can potentially be used to limit the effects of rf breakdown and pulsed surface heating at high accelerating gradients. Understanding the longitudinal stability and the acceptance of such a cavity is important to their development and use. The general Hamiltonian for longitudinal stability in multi harmonic cavities is derived and the particle dynamics are explored.
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MOPMA016	Coupler RF Kick in the Input 1.3 GHz Accelerating Cavity of the LCLS-II Linac	cavity, focusing, HOM, emittance	571
	A. Lunin, N. Solyak, A.I. Sukhanov, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	Main and HOM couplers break the cavity axial symmetry, distort RF field and, thus, create a transverse kick, even for a particle moving along the cavity axes. Dependence of a kick on the RF phase causes a beam emittance dilution and degrade the FEL radiation quality. The transverse kick is most dangerous for a beam passing through the first accelerating structure of a linac, where particles energy and their relativistic mass are low. In the paper we analyze the coupler RF kick in the first accelerating structure of the LCSL-II linac.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMA016
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TUPJE080	First Beam and High-Gradient Cryomodule Commissioning Results of the Advanced Superconducting Test Accelerator at Fermilab	cavity, cryomodule, dipole, diagnostics	1831
	D.J. Crawford, C.M. Baffes, D.R. Broemmelsiek, K. Carlson, B.E. Chase, E. Cullerton, J.S. Diamond, N. Eddy, D.R. Edstrom, E.R. Harms, A. Hocker, C.D. Joe, A.L. Klebaner, M.J. Kucera, J.R. Leibfritz, A.H. Lumpkin, J.N. Makara, S. Nagaitsev, O.A. Nezhevenko, D.J. Nicklaus, L.E. Nobrega, P. Piot, P.S. Prieto, J. Reid, J. Ruan, J.K. Santucci, W.M. Soyars, G. Stancari, D. Sun, R.M. Thurman-Keup, A. Valishev, A. Warner, S.J. Wesseln Fermilab, Batavia, Illinois, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The advanced superconducting test accelerator at Fermilab has accelerated electrons to 20 MeV and, separately, the International Linear Collider (ILC) style 8-cavity cryomodule has achieved the ILC performance milestone of 31.5 MV/m per cavity. When fully completed, the accelerator will consist of a photoinjector, one ILC-type cryomodule, multiple accelerator R&D beamlines, and a downstream beamline to inject 300 MeV electrons into the Integrable Optics Test Accelerator (IOTA). We report on the results of first beam, the achievement of our cryomodule to ILC gradient specifications, and near-term future plans for the facility.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE080
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WEPWA046	Time Domain Simulations of Detuned Accelerating Cavities for Two Beam Applications	cavity, simulation, impedance, cathode	2605
	R.M. Jones, L.R. Carver UMAN, Manchester, United Kingdom
	A multi-harmonic accelerating cavity that has its fundamental and harmonic mode frequency detuned away from the bunch repetition frequency could provide the basis for a beam driven wakefield accelerator with high transformer ratios. The excitation of multiple harmonic eigenmodes will allow high gradients to be achieved without encouraging the onset of rf breakdown or pulsed surface heating. This accelerating cavity will be introduced, and time domain simulations verifying the theory will be shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA046
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WEPMA008	RF Design of a High Gradient S-Band Travelling Wave Accelerating Structure for Thomx Linac	impedance, linac, simulation, vacuum	2757
	M. El Khaldi, L. Garolfi LAL, Orsay, France
	There is growing demand from the industrial and research communities for high gradient, compact RF accelerating structures. The Thomx high gradient structure (HGS) is travelling wave (TW), quasi constant gradient section and will operate at 2998.55 MHz (30°C in vacuum) in the 2π/3 mode. The optimization of the cell shape (Electromagnetic design) has been carried out with the codes HFSS and CST MWS, in order to improve the main RF characteristics of the cavity such as shunt impedance, accelerating gradient, group velocity, modified Poynting vector, surface fields, etc. Prototypes with a reduced number of cells have been designed. For an input power of about 20 MW, EM simulation results show that an average accelerating gradient of 28 MV/m is achieved which corresponds to a peak accelerating gradient of 35 MV/m, a peak surface gradient of 44 MV/m and peak modified Poynting vector S_cmax of 0.24 MW/mm².
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA008
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WEPMA009	3 GHz Single Cell Cavity Optimization Design	linac, simulation, cavity, electron	2761
	L. Garolfi, M. El Khaldi LAL, Orsay, France N. Faure PMB-ALCEN, PEYNIER, France
	In order to develop a high gradient S-band electron accelerating structure, an optimized travelling wave (TW) single-cell cavity operating at the frequency of 3 GHz with 2π/3 phase advance, is proposed. Starting from the well-known accelerating cells design developed by the Laboratoire de l'Accélérateur Linéaire (LAL) and the Stanford Linear Accelerator Centre (SLAC), for linear accelerators; it is possible to improve the main RF parameters, such as quality factor, shunt impedance, enhancement factor and group velocity, by choosing a suitable shape of the inner surface. Even though surface electric field is being considered as the only main quantity limiting the accelerating gradient; the importance of power flow and the modified Poynting vector, has been highlighted from high-gradient experimental data. In this context, the new field quantity (Sc) is derived from a model describing the RF breakdown trigger phenomenon wherein field emission currents from potential breakdown sites produce local pulsed heating. In particular, the modified Poynting vector takes into account both active and reactive power flow travelling along the structure. The main results presented in this paper have been carried out with the 3D electromagnetic simulation codes: High Frequency Structural Simulator solver (HFSS) and CST MICROWAVE STUDIO (CST MWS). A. Grudiev et al., "New local field quantity describing the high gradient limit of accelerating structures", PRST:AB 12, 102001 (2009).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA009
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WEPHA058	Superconducting Coatings Synthesized by CVD/PECVD for SRF Cavities	niobium, superconductivity, SRF, plasma	3246
	P. Pizzol, P. Chalker, T. Heil The University of Liverpool, Liverpool, United Kingdom A.N. Hannah, O.B. Malyshev, S.M. Pattalwar, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G.B.G. Stenning STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Funding: STFC Bulk niobium cavities are widely employed in particle accelerators to create high accelerating gradient despite their high material and operation cost. In order to reduce this cost, thin layer of niobium are deposited on a copper cavity, which has lower material cost with higher availability and more importantly higher thermal conductivity. The coating of superconducting cavities currently is synthesized by physical vapour deposition (PVD) method which suffers from lack of conformity. By using chemical vapour deposition (CVD) and plasma enhanced chemical vapour deposition (PECVD) it is possible to deposit thin Nb layers uniformly with density very close to bulk material. This project explores the use of PECVD / CVD techniques to deposit metallic niobium on copper using NbCl5 as precursor and hydrogen as a coreagent. The samples obtained were then characterized via SEM, TEM, SAD, XRD, XPS, and EDX as well as assessing their superconductivity characteristics (RRR and Tc) All the samples deposited are superconductive and polycrystalline; the sample obtained with CVD measured RRR=31 and Tc=7.9 K, while the sample obtained with PECVD exhibited RRR=9 and Tc= 9.4 K. In both cases the films grew in a (100) preferred orientation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA058
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WEPTY074	Recent Studies on the Current Limitations of State-of-the-Art Nb3Sn Cavities	cavity, niobium, cryomodule, controls	3454
	D.L. Hall, M. Liepe, J.T. Maniscalco, S. Posen Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA Th. Proslier ANL, Argonne, Illinois, USA
	Funding: NSF PHY-1305500 PHY-14116318 DOE ER41802 Recent advances in the study of Nb3Sn at Cornell University have yielded single-cell cavities that show excellent performance without the limiting Q-slope seen in previous work. This performance has been shown to be repeatable across multiple cavities. However, they are still limited by a quench field of approximately 16 MV/m, as well as residual resistance. In this work we present results quantifying the impact of ambient magnetic fields on Nb3Sn cavities, as well as discuss the impact of cavity cooldown procedures on cavity performance. Finally, we will briefly discuss XRD results that shed light on the composition of the Nb3Sn layer and how this relates to the current limits of these cavities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY074
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WEPWI009	Nitrogen Doping Study in Ingot Niobium Cavities	cavity, niobium, SRF, radio-frequency	3506
	P. Dhakal, G. Ciovati, P. Kneisel, G.R. Myneni JLab, Newport News, Virginia, USA J. Makita ODU, Norfolk, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 Thermal diffusion of nitrogen in superconducting radio frequency cavities at temperatures around 800C has resulted in the increase in quality factor with a low-field Q-rise. However, the maximum accelerating gradients of these doped cavities often reduces below the values achieved by standard treatments. In this contribution, we present the results of the nitrogen diffusion into ingot niobium cavities subjected to successive material removal from the inner cavity surface by electropolishing in an effort to explore the underlying cause for the gradient degradation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI009
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WEPWI010	Results from the First Single Cell Nb3Sn Cavity Coatings at JLab	cavity, niobium, network, resonance	3509
	G.V. Eremeev JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Nb3Sn is a promising superconducting material for SRF applications and has the potential to exceed the limitations of niobium. We have used the recently commissioned Nb3Sn coating system to investigate Nb3Sn coatings on several single cell cavities by applying the same coating procedure on several different single cells with different history and pre-coating surface preparation. We report on our findings with four 1.5 GHz CEBAF-shape single cell and one 1.3 GHz ILC-shape single cavities that were coated, inspected, and tested.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI010
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WEPWI045	Status of Superconducting Traveling Wave Cavity for High Gradient Linac	cavity, vacuum, cryogenics, feedback	3591
	R.A. Kostin, P.V. Avrakhov, A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA T.N. Khabiboulline, Y.M. Pischalnikov, N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	The use of a travelling wave (TW) accelerating structure with a small phase advance per cell instead of standing wave may provide a significant increase of accelerating gradient in a superconducting linear accelerator. The TW section achieves an accelerating gradient 1.2-1.4 times larger than TESLA-shaped standing wave cavities for the same surface electric and magnetic fields. The final stage of a 3-cell superconducting travelling wave cavity development is presented. This cavity will be tested in travelling wave regime at cryogenic temperature.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI045
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THPF084	ProTec - A Normal-conducting Cyclinac for Proton Therapy Research and Radioisotope Production	cyclotron, proton, linac, cavity	3883
	R. Apsimon, G. Burt, S. Pitman Cockcroft Institute, Lancaster University, Lancaster, United Kingdom A. Degiovanni CERN, Geneva, Switzerland J.A. Mitchell Lancaster University, Lancaster, United Kingdom H.L. Owen UMAN, Manchester, United Kingdom
	The ProTec cyclinac proposes the use of a 24 MeV high-current cyclotron to inject protons into a normal-conducting linac pulsed at up to 1 kHz to give energies up to 150 MeV. As well as being able to produce radioisotopes such as 99mTc, the cyclinac can also provide protons at higher energy with beam properties relevant for proton therapy research. In this paper we present a comparison of linac designs in which S-band structures are used at lower energies, prior to injection into a high-gradient X-band structure; issues such as beam capture and transmission are evaluated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF084
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Paper

Title

Other Keywords

Page

MOPJE081

Longitudinal Stability in Multi-Harmonic Accelerating Cavities

cavity, acceleration, cathode, controls

506

R.M. Jones, L.R. Carver
UMAN, Manchester, United Kingdom
J.L. Hirshfield
Yale University, Physics Department, New Haven, CT, USA
Y. Jiang
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA

Accelerating cavities that excite multiple modes at integer harmonics of the fundamental frequency can potentially be used to limit the effects of rf breakdown and pulsed surface heating at high accelerating gradients. Understanding the longitudinal stability and the acceptance of such a cavity is important to their development and use. The general Hamiltonian for longitudinal stability in multi harmonic cavities is derived and the particle dynamics are explored.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE081

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MOPMA016

Coupler RF Kick in the Input 1.3 GHz Accelerating Cavity of the LCLS-II Linac

cavity, focusing, HOM, emittance

571

A. Lunin, N. Solyak, A.I. Sukhanov, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Main and HOM couplers break the cavity axial symmetry, distort RF field and, thus, create a transverse kick, even for a particle moving along the cavity axes. Dependence of a kick on the RF phase causes a beam emittance dilution and degrade the FEL radiation quality. The transverse kick is most dangerous for a beam passing through the first accelerating structure of a linac, where particles energy and their relativistic mass are low. In the paper we analyze the coupler RF kick in the first accelerating structure of the LCSL-II linac.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMA016

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TUPJE080

First Beam and High-Gradient Cryomodule Commissioning Results of the Advanced Superconducting Test Accelerator at Fermilab

cavity, cryomodule, dipole, diagnostics

1831

D.J. Crawford, C.M. Baffes, D.R. Broemmelsiek, K. Carlson, B.E. Chase, E. Cullerton, J.S. Diamond, N. Eddy, D.R. Edstrom, E.R. Harms, A. Hocker, C.D. Joe, A.L. Klebaner, M.J. Kucera, J.R. Leibfritz, A.H. Lumpkin, J.N. Makara, S. Nagaitsev, O.A. Nezhevenko, D.J. Nicklaus, L.E. Nobrega, P. Piot, P.S. Prieto, J. Reid, J. Ruan, J.K. Santucci, W.M. Soyars, G. Stancari, D. Sun, R.M. Thurman-Keup, A. Valishev, A. Warner, S.J. Wesseln
Fermilab, Batavia, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The advanced superconducting test accelerator at Fermilab has accelerated electrons to 20 MeV and, separately, the International Linear Collider (ILC) style 8-cavity cryomodule has achieved the ILC performance milestone of 31.5 MV/m per cavity. When fully completed, the accelerator will consist of a photoinjector, one ILC-type cryomodule, multiple accelerator R&D beamlines, and a downstream beamline to inject 300 MeV electrons into the Integrable Optics Test Accelerator (IOTA). We report on the results of first beam, the achievement of our cryomodule to ILC gradient specifications, and near-term future plans for the facility.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE080

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WEPWA046

Time Domain Simulations of Detuned Accelerating Cavities for Two Beam Applications

cavity, simulation, impedance, cathode

2605

R.M. Jones, L.R. Carver
UMAN, Manchester, United Kingdom

A multi-harmonic accelerating cavity that has its fundamental and harmonic mode frequency detuned away from the bunch repetition frequency could provide the basis for a beam driven wakefield accelerator with high transformer ratios. The excitation of multiple harmonic eigenmodes will allow high gradients to be achieved without encouraging the onset of rf breakdown or pulsed surface heating. This accelerating cavity will be introduced, and time domain simulations verifying the theory will be shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA046

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WEPMA008

RF Design of a High Gradient S-Band Travelling Wave Accelerating Structure for Thomx Linac

impedance, linac, simulation, vacuum

2757

M. El Khaldi, L. Garolfi
LAL, Orsay, France

There is growing demand from the industrial and research communities for high gradient, compact RF accelerating structures. The Thomx high gradient structure (HGS) is travelling wave (TW), quasi constant gradient section and will operate at 2998.55 MHz (30°C in vacuum) in the 2π/3 mode. The optimization of the cell shape (Electromagnetic design) has been carried out with the codes HFSS and CST MWS, in order to improve the main RF characteristics of the cavity such as shunt impedance, accelerating gradient, group velocity, modified Poynting vector, surface fields, etc. Prototypes with a reduced number of cells have been designed. For an input power of about 20 MW, EM simulation results show that an average accelerating gradient of 28 MV/m is achieved which corresponds to a peak accelerating gradient of 35 MV/m, a peak surface gradient of 44 MV/m and peak modified Poynting vector S_cmax of 0.24 MW/mm².

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA008

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WEPMA009

3 GHz Single Cell Cavity Optimization Design

linac, simulation, cavity, electron

2761

L. Garolfi, M. El Khaldi
LAL, Orsay, France
N. Faure
PMB-ALCEN, PEYNIER, France

In order to develop a high gradient S-band electron accelerating structure, an optimized travelling wave (TW) single-cell cavity operating at the frequency of 3 GHz with 2π/3 phase advance, is proposed. Starting from the well-known accelerating cells design developed by the Laboratoire de l'Accélérateur Linéaire (LAL) and the Stanford Linear Accelerator Centre (SLAC), for linear accelerators; it is possible to improve the main RF parameters, such as quality factor, shunt impedance, enhancement factor and group velocity, by choosing a suitable shape of the inner surface. Even though surface electric field is being considered as the only main quantity limiting the accelerating gradient; the importance of power flow and the modified Poynting vector*, has been highlighted from high-gradient experimental data. In this context, the new field quantity (Sc) is derived from a model describing the RF breakdown trigger phenomenon wherein field emission currents from potential breakdown sites produce local pulsed heating. In particular, the modified Poynting vector takes into account both active and reactive power flow travelling along the structure. The main results presented in this paper have been carried out with the 3D electromagnetic simulation codes: High Frequency Structural Simulator solver (HFSS) and CST MICROWAVE STUDIO (CST MWS).
* A. Grudiev et al., "New local field quantity describing the high gradient limit of accelerating structures", PRST:AB 12, 102001 (2009).

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WEPHA058

Superconducting Coatings Synthesized by CVD/PECVD for SRF Cavities

niobium, superconductivity, SRF, plasma

3246

P. Pizzol, P. Chalker, T. Heil
The University of Liverpool, Liverpool, United Kingdom
A.N. Hannah, O.B. Malyshev, S.M. Pattalwar, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G.B.G. Stenning
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Funding: STFC
Bulk niobium cavities are widely employed in particle accelerators to create high accelerating gradient despite their high material and operation cost. In order to reduce this cost, thin layer of niobium are deposited on a copper cavity, which has lower material cost with higher availability and more importantly higher thermal conductivity. The coating of superconducting cavities currently is synthesized by physical vapour deposition (PVD) method which suffers from lack of conformity. By using chemical vapour deposition (CVD) and plasma enhanced chemical vapour deposition (PECVD) it is possible to deposit thin Nb layers uniformly with density very close to bulk material. This project explores the use of PECVD / CVD techniques to deposit metallic niobium on copper using NbCl5 as precursor and hydrogen as a coreagent. The samples obtained were then characterized via SEM, TEM, SAD, XRD, XPS, and EDX as well as assessing their superconductivity characteristics (RRR and Tc) All the samples deposited are superconductive and polycrystalline; the sample obtained with CVD measured RRR=31 and Tc=7.9 K, while the sample obtained with PECVD exhibited RRR=9 and Tc= 9.4 K. In both cases the films grew in a (100) preferred orientation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA058

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WEPTY074

Recent Studies on the Current Limitations of State-of-the-Art Nb3Sn Cavities

cavity, niobium, cryomodule, controls

3454

D.L. Hall, M. Liepe, J.T. Maniscalco, S. Posen
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
Th. Proslier
ANL, Argonne, Illinois, USA

Funding: NSF PHY-1305500 PHY-14116318 DOE ER41802
Recent advances in the study of Nb3Sn at Cornell University have yielded single-cell cavities that show excellent performance without the limiting Q-slope seen in previous work. This performance has been shown to be repeatable across multiple cavities. However, they are still limited by a quench field of approximately 16 MV/m, as well as residual resistance. In this work we present results quantifying the impact of ambient magnetic fields on Nb3Sn cavities, as well as discuss the impact of cavity cooldown procedures on cavity performance. Finally, we will briefly discuss XRD results that shed light on the composition of the Nb3Sn layer and how this relates to the current limits of these cavities.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY074

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WEPWI009

Nitrogen Doping Study in Ingot Niobium Cavities

cavity, niobium, SRF, radio-frequency

3506

P. Dhakal, G. Ciovati, P. Kneisel, G.R. Myneni
JLab, Newport News, Virginia, USA
J. Makita
ODU, Norfolk, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177
Thermal diffusion of nitrogen in superconducting radio frequency cavities at temperatures around 800C has resulted in the increase in quality factor with a low-field Q-rise. However, the maximum accelerating gradients of these doped cavities often reduces below the values achieved by standard treatments. In this contribution, we present the results of the nitrogen diffusion into ingot niobium cavities subjected to successive material removal from the inner cavity surface by electropolishing in an effort to explore the underlying cause for the gradient degradation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI009

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WEPWI010

Results from the First Single Cell Nb3Sn Cavity Coatings at JLab

cavity, niobium, network, resonance

3509

G.V. Eremeev
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Nb3Sn is a promising superconducting material for SRF applications and has the potential to exceed the limitations of niobium. We have used the recently commissioned Nb3Sn coating system to investigate Nb3Sn coatings on several single cell cavities by applying the same coating procedure on several different single cells with different history and pre-coating surface preparation. We report on our findings with four 1.5 GHz CEBAF-shape single cell and one 1.3 GHz ILC-shape single cavities that were coated, inspected, and tested.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI010

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WEPWI045

Status of Superconducting Traveling Wave Cavity for High Gradient Linac

cavity, vacuum, cryogenics, feedback

3591

R.A. Kostin, P.V. Avrakhov, A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
T.N. Khabiboulline, Y.M. Pischalnikov, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

The use of a travelling wave (TW) accelerating structure with a small phase advance per cell instead of standing wave may provide a significant increase of accelerating gradient in a superconducting linear accelerator. The TW section achieves an accelerating gradient 1.2-1.4 times larger than TESLA-shaped standing wave cavities for the same surface electric and magnetic fields. The final stage of a 3-cell superconducting travelling wave cavity development is presented. This cavity will be tested in travelling wave regime at cryogenic temperature.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI045

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THPF084

ProTec - A Normal-conducting Cyclinac for Proton Therapy Research and Radioisotope Production

cyclotron, proton, linac, cavity

3883

R. Apsimon, G. Burt, S. Pitman
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
A. Degiovanni
CERN, Geneva, Switzerland
J.A. Mitchell
Lancaster University, Lancaster, United Kingdom
H.L. Owen
UMAN, Manchester, United Kingdom

The ProTec cyclinac proposes the use of a 24 MeV high-current cyclotron to inject protons into a normal-conducting linac pulsed at up to 1 kHz to give energies up to 150 MeV. As well as being able to produce radioisotopes such as 99mTc, the cyclinac can also provide protons at higher energy with beam properties relevant for proton therapy research. In this paper we present a comparison of linac designs in which S-band structures are used at lower energies, prior to injection into a high-gradient X-band structure; issues such as beam capture and transmission are evaluated.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF084

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