LINAC2022 - Classification: Proton and Ion Accelerators and Applications / Room temperature structures

Paper	Title	Page
MOPOGE11	Update on the First 3D Printed IH-Type Linac Structure - Proof-of-Concept for Additive Manufacturing of Linac RF Cavities	170
	H. Hähnel, A. Ateş, U. Ratzinger IAP, Frankfurt am Main, Germany
	Funding: This research was funded by BBMBF grant number 05P21RFRB2. Additive manufacturing ("AM" or "3D printing") has become a powerful tool for rapid prototyping and manufacturing of complex geometries. A 433 MHz IH-DTL cavity has been constructed to act as a proof of concept for additive manufacturing of linac components. In this case, the internal drift tube structure has been produced from 1.4404 stainless steel using AM. We present the concept of the cavity as well as first results of vacuum testing, materials testing and low level rf measurements. Vacuum levels sufficient for linac operation have been reached with the AM linac structure.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE11
About •	Received ※ 22 August 2022 — Accepted ※ 28 August 2022 — Issue date ※ 02 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOGE12	Cavity R&D for HBS Accelerator	174
SUPCPA03	use link to see paper's listing under its alternate paper code
	N.F. Petry, K. Kümpel, S. Lamprecht, O. Meusel, H. Podlech, M. Schwarz IAP, Frankfurt am Main, Germany
	The demand for neutrons of various types for research is growing day by day worldwide. To meet the growing demand the Jülich High Brilliance Neutron Source (HBS) is in development. It is based on a high power linear proton accelerator with an end energy of 70 MeV and a proton beam current of 100 mA. The main part of the accelerator consists of about 45 CH-type cavities. As the current beam dynamic layout is still work in progress the number of cavities can change for the final design. For this beam dynamic layout the design of the CH-type cavities was optimized to handle the high accelerating gradient. The results of the performance of the CH-type cavities will be presented in this paper.
	Poster MOPOGE12 [1.286 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE12
About •	Received ※ 17 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 15 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOGE13	Acceleration Efficiency of TE-Mode Structures for Proton Linacs	177
	J. Tamura, Y. Kondo, T. Morishita JAEA/J-PARC, Tokai-mura, Japan F. Naito, M. Otani KEK, Tokai, Ibaraki, Japan
	Various types of cavity structures are typically used in hadron linacs, depending on the energy range of the beam particle. This is especially the case in a normal-conducting linac, because the cavity’s acceleration efficiency varies with the velocity of the synchronous particle. For low-energy proton acceleration, while Alvarez drift-tube linacs (DTLs) are the most prevalent, TE-mode accelerating structures, which could also be called H-mode structures, are also widely used immediately after an initial radiofrequency quadrupole linac (RFQ). At present, the representative structures of TE modes are interdigital H-mode (IH) DTL and crossbar H-mode (CH) DTL, which are based on the TE11-mode pillbox cavity and TE21-mode pillbox cavity, respectively. In this presentation, acceleration efficiency of TE-mode structures including higher-order TE-modes such as TE31 and TE41 was comparatively reviewed with Alvarez DTL. This study shows that IH-DTL and CH-DTL have a larger shunt impedance than Alvarez DTL for proton acceleration below 10 MeV, and furthermore for the TEm1-mode structures, the rotational symmetry of the electric field improves with increasing angular index m.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE13
About •	Received ※ 30 August 2022 — Revised ※ 06 September 2022 — Accepted ※ 14 September 2022 — Issue date ※ 26 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOGE15	Operation of the H⁻ Linac at FNAL	184
	K. Seiya, T.A. Butler, A. Hartman, D.C. Jones, V.V. Kapin, S. Moua, J.-F. Ostiguy, R. Ridgway, R.V. Sharankova, B.S. Stanzil, C.-Y. Tan, M.E. Wesley Fermilab, Batavia, Illinois, USA M.W. Mwaniki IIT, Chicago, Illinois, USA
	The Fermi National Accelerator Laboratory (FNAL) Linac has been in operation for 52 years. the Linac delivers H⁻ ions at 400 MeV and injects protons by charge exchange into the Booster synchrotron. Despite its age, the Linac is the most stable accelerator in the FNAL complex, reliably sending 22 mA in daily operations. We will discuss the status of the operation, beam studies, and plans.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE15
About •	Received ※ 16 August 2022 — Revised ※ 19 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 11 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOGE16	Development of High-Gradient Accelerating Structures for Proton Radiography Booster at LANSCE	188
	S.S. Kurennoy, Y.K. Batygin, E.R. Olivas LANL, Los Alamos, New Mexico, USA
	Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV improves radiography resolution ~10 times. We propose accomplishing this energy boost with a compact cost-effective linac based on normal conducting high-gradient (HG) RF accelerating structures. Such an unusual proton linac is feasible for proton radiography (pRad), which operates with very short beam (and RF) pulses. For a compact pRad booster at LANSCE, we have developed a multi-stage design: a short L-band section to capture and compress the 800-MeV proton beam from the existing linac followed by the main HG linac based on S- and C-band cavities, and finally, by an L-band de-buncher. Here we present details of development, including EM and thermal-stress analysis, of proton HG structures with distributed RF coupling for the pRad booster. A short test structure is designed specifically for measurements at the LANL C-band RF Test Stand. S.S. Kurennoy, Y.K. Batygin. IPAC21, MOPAB210.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE16
About •	Received ※ 23 August 2022 — Accepted ※ 02 September 2022 — Issue date ※ 03 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOGE17	CST Modeling of the LANSCE Coupled-Cavity Linac	191
	S.S. Kurennoy, Y.K. Batygin LANL, Los Alamos, New Mexico, USA
	The 800-MeV proton linac at LANSCE consists of a drift-tube linac, which brings the beam to 100 MeV, followed by 44 modules of a coupled-cavity linac (CCL). Each CCL module contains multiple tanks, and it is fed by a single 805-MHz klystron. CCL tanks are multi-cell blocks of identical re-entrant side-coupled cavities, which are followed by drifts with magnetic quadrupole doublets. Bridge couplers - special cavities displaced from the beam axis - electromagnetically couple CCL tanks over such drifts within a module. We have developed 3D CST models of CCL tanks. The models are used to calculate electromagnetic fields in the tanks. Beam dynamics is modelled in CST for bunch trains with realistic beam distributions using the calculated RF fields and quadrupole magnetic fields. Beam dynamics results are crosschecked with other multi-particle codes and applied to evaluate effects of CCL misalignments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE17
About •	Received ※ 22 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 02 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOGE18	Design of IH-DTL to Accelerate Intense Lithium-Ion Beam for Compact Neutron Source	194
	S. Ikeda, T. Kanesue, M. Okamura BNL, Upton, New York, USA
	We are studying feasibility of a compact neutron source with a lithium-ion beam driver. The neutron source com-prises a laser ion source, an RFQ linac, and an IH-DTL. Recently, we demonstrated 35-mA 7Li³⁺ ion beam acceler-ation by an RFQ linac with a laser ion source. Based on the result, we performed beam dynamic design of an IH-DTL to accelerate the lithium-ion beam to the energy required for the neutron production, 14 MeV. To obtain a realistic field distribution, we made a rough model of the IH-DTL cavity with Microwave studio. It was confirmed with GPT 3D beam simulation that 1.7-m and 200-kW IH-DTL with two triplets can accelerate 30-mA 7Li³⁺ beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE18
About •	Received ※ 02 September 2022 — Revised ※ 05 September 2022 — Accepted ※ 09 September 2022 — Issue date ※ 13 October 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FR1AA01	Beam Commissioning and Operation Status of LEAF
	Y. Yang, L.T. Sun, H.W. Zhao IMP/CAS, Lanzhou, People’s Republic of China
	LEAF (Low Energy heavy ion Accelerator Facility) is a low energy high intensity heavy ion accelerator complex for multidiscipline researches that features a high performance superconducting ECR (Electron Cyclotron Resonance) ion source, and a high current heavy ion beam lianc. The facility has been put into commissioning since 2018. The RFQ has successfully accelerated the beams with M/q within 2~7 in the CW regime. High transmission efficiencies (typically higher than 97%) were relatively easy to achieve for beam currents of ~0.1 emA level. Experimental research such as C-C burning investigation in nuclear astrophysics needs intense heavy ion beam of a broad beam energy variation while maintaining very low energy spread. A setup of ion beam energy modulation system has been developed, which is mainly composed of a drift tube linac (DTL) for beam energy tuning and two quarter wave resonator (QWR) re-bunchers placed at upstream and downstream of the DTL respectively for beam quality control and longitudinal matching. More than 0.05 pmA carbon beam with an energy spread of <0.3% (FWHM) has been delivered to the experimental terminal.

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	Slides FR1AA01 [4.344 MB]
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Paper

Title

Page

Update on the First 3D Printed IH-Type Linac Structure - Proof-of-Concept for Additive Manufacturing of Linac RF Cavities

170

H. Hähnel, A. Ateş, U. Ratzinger
IAP, Frankfurt am Main, Germany

Funding: This research was funded by BBMBF grant number 05P21RFRB2.
Additive manufacturing ("AM" or "3D printing") has become a powerful tool for rapid prototyping and manufacturing of complex geometries. A 433 MHz IH-DTL cavity has been constructed to act as a proof of concept for additive manufacturing of linac components. In this case, the internal drift tube structure has been produced from 1.4404 stainless steel using AM. We present the concept of the cavity as well as first results of vacuum testing, materials testing and low level rf measurements. Vacuum levels sufficient for linac operation have been reached with the AM linac structure.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE11

About •

Received ※ 22 August 2022 — Accepted ※ 28 August 2022 — Issue date ※ 02 September 2022

Cite •

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

MOPOGE12

Cavity R&D for HBS Accelerator

174

SUPCPA03

use link to see paper's listing under its alternate paper code

N.F. Petry, K. Kümpel, S. Lamprecht, O. Meusel, H. Podlech, M. Schwarz
IAP, Frankfurt am Main, Germany

The demand for neutrons of various types for research is growing day by day worldwide. To meet the growing demand the Jülich High Brilliance Neutron Source (HBS) is in development. It is based on a high power linear proton accelerator with an end energy of 70 MeV and a proton beam current of 100 mA. The main part of the accelerator consists of about 45 CH-type cavities. As the current beam dynamic layout is still work in progress the number of cavities can change for the final design. For this beam dynamic layout the design of the CH-type cavities was optimized to handle the high accelerating gradient. The results of the performance of the CH-type cavities will be presented in this paper.

Poster MOPOGE12 [1.286 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE12

About •

Received ※ 17 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 15 September 2022

Cite •

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

MOPOGE13

Acceleration Efficiency of TE-Mode Structures for Proton Linacs

177

J. Tamura, Y. Kondo, T. Morishita
JAEA/J-PARC, Tokai-mura, Japan
F. Naito, M. Otani
KEK, Tokai, Ibaraki, Japan

Various types of cavity structures are typically used in hadron linacs, depending on the energy range of the beam particle. This is especially the case in a normal-conducting linac, because the cavity’s acceleration efficiency varies with the velocity of the synchronous particle. For low-energy proton acceleration, while Alvarez drift-tube linacs (DTLs) are the most prevalent, TE-mode accelerating structures, which could also be called H-mode structures, are also widely used immediately after an initial radiofrequency quadrupole linac (RFQ). At present, the representative structures of TE modes are interdigital H-mode (IH) DTL and crossbar H-mode (CH) DTL, which are based on the TE11-mode pillbox cavity and TE21-mode pillbox cavity, respectively. In this presentation, acceleration efficiency of TE-mode structures including higher-order TE-modes such as TE31 and TE41 was comparatively reviewed with Alvarez DTL. This study shows that IH-DTL and CH-DTL have a larger shunt impedance than Alvarez DTL for proton acceleration below 10 MeV, and furthermore for the TEm1-mode structures, the rotational symmetry of the electric field improves with increasing angular index m.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE13

About •

Received ※ 30 August 2022 — Revised ※ 06 September 2022 — Accepted ※ 14 September 2022 — Issue date ※ 26 September 2022

Cite •

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

MOPOGE15

Operation of the H⁻ Linac at FNAL

184

K. Seiya, T.A. Butler, A. Hartman, D.C. Jones, V.V. Kapin, S. Moua, J.-F. Ostiguy, R. Ridgway, R.V. Sharankova, B.S. Stanzil, C.-Y. Tan, M.E. Wesley
Fermilab, Batavia, Illinois, USA
M.W. Mwaniki
IIT, Chicago, Illinois, USA

The Fermi National Accelerator Laboratory (FNAL) Linac has been in operation for 52 years. the Linac delivers H⁻ ions at 400 MeV and injects protons by charge exchange into the Booster synchrotron. Despite its age, the Linac is the most stable accelerator in the FNAL complex, reliably sending 22 mA in daily operations. We will discuss the status of the operation, beam studies, and plans.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE15

About •

Received ※ 16 August 2022 — Revised ※ 19 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 11 September 2022

Cite •

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

MOPOGE16

Development of High-Gradient Accelerating Structures for Proton Radiography Booster at LANSCE

188

S.S. Kurennoy, Y.K. Batygin, E.R. Olivas
LANL, Los Alamos, New Mexico, USA

Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV improves radiography resolution ~10 times. We propose accomplishing this energy boost with a compact cost-effective linac based on normal conducting high-gradient (HG) RF accelerating structures. Such an unusual proton linac is feasible for proton radiography (pRad), which operates with very short beam (and RF) pulses. For a compact pRad booster at LANSCE, we have developed a multi-stage design: a short L-band section to capture and compress the 800-MeV proton beam from the existing linac followed by the main HG linac based on S- and C-band cavities, and finally, by an L-band de-buncher*. Here we present details of development, including EM and thermal-stress analysis, of proton HG structures with distributed RF coupling for the pRad booster. A short test structure is designed specifically for measurements at the LANL C-band RF Test Stand.
* S.S. Kurennoy, Y.K. Batygin. IPAC21, MOPAB210.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE16

About •

Received ※ 23 August 2022 — Accepted ※ 02 September 2022 — Issue date ※ 03 September 2022

Cite •

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

MOPOGE17

CST Modeling of the LANSCE Coupled-Cavity Linac

191

S.S. Kurennoy, Y.K. Batygin
LANL, Los Alamos, New Mexico, USA

The 800-MeV proton linac at LANSCE consists of a drift-tube linac, which brings the beam to 100 MeV, followed by 44 modules of a coupled-cavity linac (CCL). Each CCL module contains multiple tanks, and it is fed by a single 805-MHz klystron. CCL tanks are multi-cell blocks of identical re-entrant side-coupled cavities, which are followed by drifts with magnetic quadrupole doublets. Bridge couplers - special cavities displaced from the beam axis - electromagnetically couple CCL tanks over such drifts within a module. We have developed 3D CST models of CCL tanks. The models are used to calculate electromagnetic fields in the tanks. Beam dynamics is modelled in CST for bunch trains with realistic beam distributions using the calculated RF fields and quadrupole magnetic fields. Beam dynamics results are crosschecked with other multi-particle codes and applied to evaluate effects of CCL misalignments.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE17

About •

Received ※ 22 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 02 September 2022

Cite •

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

MOPOGE18

Design of IH-DTL to Accelerate Intense Lithium-Ion Beam for Compact Neutron Source

194

S. Ikeda, T. Kanesue, M. Okamura
BNL, Upton, New York, USA

We are studying feasibility of a compact neutron source with a lithium-ion beam driver. The neutron source com-prises a laser ion source, an RFQ linac, and an IH-DTL. Recently, we demonstrated 35-mA 7Li³⁺ ion beam acceler-ation by an RFQ linac with a laser ion source. Based on the result, we performed beam dynamic design of an IH-DTL to accelerate the lithium-ion beam to the energy required for the neutron production, 14 MeV. To obtain a realistic field distribution, we made a rough model of the IH-DTL cavity with Microwave studio. It was confirmed with GPT 3D beam simulation that 1.7-m and 200-kW IH-DTL with two triplets can accelerate 30-mA 7Li³⁺ beam.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE18

About •

Received ※ 02 September 2022 — Revised ※ 05 September 2022 — Accepted ※ 09 September 2022 — Issue date ※ 13 October 2022

Cite •

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

FR1AA01

Beam Commissioning and Operation Status of LEAF

Y. Yang, L.T. Sun, H.W. Zhao
IMP/CAS, Lanzhou, People’s Republic of China

LEAF (Low Energy heavy ion Accelerator Facility) is a low energy high intensity heavy ion accelerator complex for multidiscipline researches that features a high performance superconducting ECR (Electron Cyclotron Resonance) ion source, and a high current heavy ion beam lianc. The facility has been put into commissioning since 2018. The RFQ has successfully accelerated the beams with M/q within 2~7 in the CW regime. High transmission efficiencies (typically higher than 97%) were relatively easy to achieve for beam currents of ~0.1 emA level. Experimental research such as C-C burning investigation in nuclear astrophysics needs intense heavy ion beam of a broad beam energy variation while maintaining very low energy spread. A setup of ion beam energy modulation system has been developed, which is mainly composed of a drift tube linac (DTL) for beam energy tuning and two quarter wave resonator (QWR) re-bunchers placed at upstream and downstream of the DTL respectively for beam quality control and longitudinal matching. More than 0.05 pmA carbon beam with an energy spread of <0.3% (FWHM) has been delivered to the experimental terminal.

please see instructions how to view/control embeded videos

Slides FR1AA01 [4.344 MB]

Cite •

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