LINAC2022 - Classification: Proton and Ion Accelerators and Applications / RFQs

Paper	Title	Page
TUPOPA03	Status and RF Devopments of ESS Bilbao RFQ	410
	N. Garmendia, I. Bustinduy, A. Conde, P.J. González, A. Kaftoosian, J. Martin, S. Masa, J.L. Muñoz, Á. Rodríguez Páramo ESS Bilbao, Zamudio, Spain
	Within the framework of the plans for study of a light-ion linear accelerator, ESS Bilbao is manufacturing a radio frequency quadrupole (RFQ) aimed at accelerating up to 3 MeV the protons generated in the ion source. The progress made and the difficulties encountered with the RFQ are discussed in this paper. A power coupler proto-type for the RFQ has been developed while several me-chanical constraints were also studied in the final cou-pler. This prototype operates at a lower power, then it can work using PEEK window for the vacuum interface and it does not require neither brazing nor cooling system. Also, a complete RF test stand is being implemented to perform the high-power conditioning in traveling and standing wave mode, to verify the power handling capa-bility of the coupler and its thermal behaviour. The RF test stand, based on EPICS environment, can provide up to 2 MW peak power at 352.2 MHz in a pulse operation of 14 Hz and a duty cycle of 4.9%.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA03
About •	Received ※ 09 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 02 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPA04	First Beam Matching and Transmission Studies on the ESS RFQ	414
	D. Noll, R.A. Baron, C.S. Derrez, E.M. Donegani, M. Eshraqi, F. Grespan, H. Hassanzadegan, B. Jones, Y. Levinsen, N. Milas, R. Miyamoto, D.C. Plostinar, A.G. Sosa, R. Zeng ESS, Lund, Sweden A.C. Chauveau, O. Piquet CEA-IRFU, Gif-sur-Yvette, France
	The European Spallation Source will be driven by a 5 MW linear accelerator, producing 2.86 ms long proton beam pulses with a peak current of 62.5 mA at 14 Hz. Following the source commissioning in 2018 and 2019, the RFQ was successfully conditioned and subsequently commissioned with beam in 2021. In this paper, we will present results of studies on beam matching to the RFQ, both for low and high current beam modes, and will compare these results to model predictions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA04
About •	Received ※ 26 August 2022 — Accepted ※ 05 September 2022 — Issue date ※ 05 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPA05	RFQ Performance During RF Conditioning and Beam Commissioning at ESS	418
	R. Zeng, G.S. Fedel, B. Jones, R. Miyamoto, D.J.P. Nicosia, D. Noll, A.G. Sosa, A.M. Svensson, E. Trachanas ESS, Lund, Sweden M. Baudrier CEA-DRF-IRFU, France A.C. Chauveau, M.J. Desmons, P. Hamel, O. Piquet CEA-IRFU, Gif-sur-Yvette, France F. Grespan INFN/LNL, Legnaro (PD), Italy
	RFQ at ESS has been successfully gone through RF conditioning, RF re-conditioning and low duty cycle beam commissioning. RFQ fulfills required functions and overall performance is satisfactory. RF conditioning, three RF re-conditionings after LEBT intervention and beam commissioning will be reported and RFQ performance during these periods will be described. RFQ performance in a large extent is reflected by dynamics and interactions between RF, cavity and beam. Thanks to advanced hardware capabilities and intelligent software intelligence, observation of those dynamics and interactions are done in detailed level. Analysis of those dynamics and interaction will be introduced. Some techniques to deal with challenges resulted from those dynamics and interactions will also be discussed.
	Poster TUPOPA05 [25.281 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA05
About •	Received ※ 18 August 2022 — Revised ※ 25 August 2022 — Accepted ※ 31 August 2022 — Issue date ※ 05 September 2022
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TUPOPA06	Microscopy Investigation on Different Materials After Pulsed High Field Conditioning and Low Energy H-Irradiation	422
SUPCJO06	use link to see paper's listing under its alternate paper code
	C.F. Da Palma Serafim, G. Bellodi, S. Calatroni, A. Grudiev, A.M. Lombardi, R.C. Peacock, A.T. Perez Fontenla, S. Ramberger, E. Sargsyan, S. Sgobba, W. Wuensch CERN, Meyrin, Switzerland F. Djurabekova HIP, University of Helsinki, Finland
	During operation the LINAC4 RFQ (Radio-Frequency-Quadrupole) is exposed to high electric fields which can lead to vacuum breakdown. It is also subject to beam loss that can cause surface modification, including blistering, which can result in reduced electric field handling and an increased breakdown rate. An experimental study has been made to identify materials with high electric field capability and robustness to low-energy irradiation. In this paper we briefly discuss the selection criteria and we analyze these materials investigating their metallurgical properties using advanced microscopic techniques such as Scanning Electron Microscope, Electron Back Scattered Diffraction, Energy-dispersive X-ray Spectroscopy and conventional optical microscopy. These allow to observe and characterize the different materials on aμand a nano-scale, allowing us to compare results before and after irradiation and breakdown testing.
	Poster TUPOPA06 [2.771 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA06
About •	Received ※ 14 August 2022 — Revised ※ 23 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 31 August 2022
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TUPOPA09	RF Measurements and Tuning of the CERN 750 MHz ELISA-RFQ for Public Exhibition	426
	M. Marchi, A. Grudiev, S.J. Mathot, H.W. Pommerenke CERN, Meyrin, Switzerland
	Over the last few years CERN has successfully designed, built and commissioned the smallest RFQ to date, the one meter long PIXE-RFQ operating at 750 MHz. Its compactness offers a unique opportunity for education and public presentation of the accelerator community: A duplicate machine called ELISA-RFQ (Experimental Linac for Surface Analysis) will be exhibited in the Science Gateway, CERN’s upcoming scientific education and outreach center. It will allow the public to approach within a few centimeters a live proton beam injected into air, which is visible to the naked eye. The construction of the ELISA-RFQ has been completed in 2022. In this paper, we present the results of low-power RF measurements as well as field and frequency tuning.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA09
About •	Received ※ 14 August 2022 — Revised ※ 18 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 01 September 2022
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TUPOPA10	Beam Dynamics and RF Design Studies for the New RFQ for CERN Linac4 Upgrade	430
	H.W. Pommerenke, G. Bellodi, A. Grudiev, S. Kumar, A.M. Lombardi CERN, Meyrin, Switzerland
	The 352 MHz Linac4-RFQ is the first rf accelerating structure of the CERN accelerator complex, accelerating an H⁻ beam to 3 MeV. After successful commissioning in 2013, superficial vane damage has been observed in 2020. In view that the RFQ is a single point of failure, in parallel to the production of a near identical spare (RFQ2), design studies on a longer-term upgrade have been launched: Linac4-RFQ3. Main goals are to achieve a design with higher beam acceptance, reduced beam losses, and reduced RF breakdown rate. Two versions of RFQ are under study: a conventional RFQ built by brazing copper, as well as an RFQ with titanium vane tips (brazed on copper). High-gradient experiments suggest that titanium vane tips support higher surface fields compared to copper, up to 40 MV/m, and are more resistant against beam irradiation. In this paper, we present beam dynamics and rfdesign of both variants of RFQ3.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA10
About •	Received ※ 12 August 2022 — Revised ※ 19 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 02 September 2022
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TUPOPA11	Compact Proton Accelerator in UHF Band At KAHVELab	434
SUPCGE07	use link to see paper's listing under its alternate paper code
	S. Esen, A. Adiguzel, O. Kocer, S. Oz Istanbul University, Istanbul, Turkey A. Caglar YTU, Istanbul, Turkey E. Celebi, E.V. Ozcan Bogazici University, Bebek / Istanbul, Turkey E. Celebi IBU, Istanbul, Turkey A.K. Karatay, F. Yaman, Ö.H. Yilmaz IZTECH, Izmir, Turkey U. Kaya Istinye University, Institute of Sciences, Istanbul, Turkey A. Kilicgedik Marmara University, Istanbul, Turkey G. Türemen Turkish Atomic Energy Authority, Ankara, Turkey G. Unel UCI, Irvine, California, USA
	Funding: This project are supported by TUBITAK Project no: 118E838 Proton Test Beam at KahveLAB (Kandilli Detector, Accelerator and Instrumentation Laboratory) project aims to design and produce a radio frequency quadrupole (RFQ) operating at 800 MHz in Istanbul, Turkey using the local resources. The beamline consists of a proton source, a low energy beam transport (LEBT) line including the beam diagnostic section, and the RFQ cavity itself. This RFQ is a 4-vane, 1-meter-long cavity to accelerate the 20 keV beam extracted from the plasma ion source to 2 MeV. Its engineering prototype is already produced and subjected to mechanical, low-power RF, and vacuum tests. In this poster, the results of the first test production, especially the bead-pull test setup will be discussed.
	Poster TUPOPA11 [16.128 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA11
About •	Received ※ 21 August 2022 — Revised ※ 22 August 2022 — Accepted ※ 12 September 2022 — Issue date ※ 26 September 2022
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TUPOPA12	RF Measurements and Tuning of the Test Module of 800 MHz Radio-Frequency Quadrupole	438
SUPCGE02	use link to see paper's listing under its alternate paper code
	A. Kilicgedik Marmara University, Istanbul, Turkey A. Adiguzel, S. Esen Istanbul University, Istanbul, Turkey B. Baran Ankara University, Faculty of Sciences, Ankara, Turkey A. Caglar YTU, Istanbul, Turkey E. Celebi, E.V. Ozcan Bogazici University, Bebek / Istanbul, Turkey U. Kaya Istinye University, Institute of Sciences, Istanbul, Turkey G. Türemen TENMAK-NUKEN, Ankara, Turkey G. Unel UCI, Irvine, California, USA F. Yaman IZTECH, Izmir, Turkey
	Funding: This project are supported by The Scientific and Technological Research Council of Turkey (TUBITAK) Project no: 118E838 The 800 MHz RFQ (radio-frequency quadrupole), developed and built at KAHVElab (Kandilli Detector, Accelerator and Instrumentation Laboratory) at Bogazici University in Istanbul, Turkey, has been designed to provide protons that have an energy of 2 MeV within only 1 m length. The RFQ consists of two modules and the test module of RFQ was constructed. The algorithm developed by CERN, based on the measurements generated by the tuner settings estimated through the response matrix [1,2,3], has been optimized for a single module and 16 tuners. The desired field consistent with the simulation was obtained by bead pull measurements. In this study, we present low-power rf measurements and field tuning of the test module. [1] Koubek, B., et al., PHY. REV. ACC. AND BEAMS 20,08010(2017) [2] Koubek, B., et al., CERN-2017-0006,(2017) [3] Pommerenke, Hermann W., et al., Nuc. Inst. and Meth. in Phy. Res. Sec.A),165564(2021)
	Poster TUPOPA12 [1.699 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA12
About •	Received ※ 24 August 2022 — Revised ※ 27 August 2022 — Accepted ※ 31 August 2022 — Issue date ※ 02 September 2022
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TUPOPA13	Pulsed DC High Field Measurements of Irradiated and Non-Irradiated Electrodes of Different Materials	441
SUPCJO07	use link to see paper's listing under its alternate paper code
	R.C. Peacock, G. Burt Lancaster University, Lancaster, United Kingdom G. Bellodi, S. Calatroni, C.F. Da Palma Serafim, A. Grudiev, A.M. Lombardi, A.T. Perez Fontenla, S. Ramberger, E. Sargsyan, S. Sgobba, W. Wuensch CERN, Meyrin, Switzerland
	Beam loss occurs in Radio Frequency Quadrupoles (RFQ), and has been observed in the H⁻ linear accelerator Linac4 (L4) at CERN. To determine if beam loss can induce breakdowns, and to compare the robustness of different materials, tests have been done using pulsed high-voltage DC systems. Electrical breakdown phenomena and conditioning processes have been studied using these systems. Cathodes of different materials were irradiated with 1.2x10¹⁹ H⁻ p/cm², the estimated beam loss of the L4 RFQ over 10 days. The irradiated electrodes were installed in a system to observe if the irradiated area coincided with the breakdown locations, with pulsing parameters similar to the RFQ. Tests of irradiated and non-irradiated electrodes of the same material were done for comparison. The main difference observed was an increase in the number of breakdowns during the initial conditioning that returned to non-irradiated sample values with further running. Visual observations after irradiation show the beam centre and a halo the same diameter of the beam pipe. Breakdown clusters occur in the centre and halo regions, suggesting irradiation is not the only factor determining the breakdown probability.
	Poster TUPOPA13 [3.845 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA13
About •	Received ※ 23 August 2022 — Revised ※ 29 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 07 September 2022
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TUPORI28	Injector System Development for 1 MeV/n RFQ at KOMAC	615
	H.S. Kim KAERI, Daejon, Republic of Korea J.J. Dang, D.-H. Kim, H.-J. Kwon, S. Lee, S.P. Yun KOMAC, KAERI, Gyeongju, Republic of Korea
	Funding: This work has been supported through the KOMAC operation fund of KAERI by the Korean government (MSIT). A Radiofrequency quadrupole (RFQ) system with 200 MHz frequency and 1 MeV/n output energy is under development at KOMAC (Korea Multi-purpose Accelerator Complex) for multiple purposes such as a test-stand for an ion source and low energy beam transport study, ion beam implantation for semiconductors and polymers and neutron generation for material study. We developed an injector system for the RFQ, which is mainly composed of a 2.45 GHz microwave ion source, low energy beam transport with two solenoids, and a vacuum system with a diagnostic chamber. The RFQ was designed to be able to accelerate the beam with 2.5 mass-to-charge ratios (A/q) but we used the proton beam for an initial test to characterize the injector system. A Detailed describtion of the constructed injector system along with test results will be given in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI28
About •	Received ※ 22 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 15 September 2022
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Paper

Title

Page

Status and RF Devopments of ESS Bilbao RFQ

410

N. Garmendia, I. Bustinduy, A. Conde, P.J. González, A. Kaftoosian, J. Martin, S. Masa, J.L. Muñoz, Á. Rodríguez Páramo
ESS Bilbao, Zamudio, Spain

Within the framework of the plans for study of a light-ion linear accelerator, ESS Bilbao is manufacturing a radio frequency quadrupole (RFQ) aimed at accelerating up to 3 MeV the protons generated in the ion source. The progress made and the difficulties encountered with the RFQ are discussed in this paper. A power coupler proto-type for the RFQ has been developed while several me-chanical constraints were also studied in the final cou-pler. This prototype operates at a lower power, then it can work using PEEK window for the vacuum interface and it does not require neither brazing nor cooling system. Also, a complete RF test stand is being implemented to perform the high-power conditioning in traveling and standing wave mode, to verify the power handling capa-bility of the coupler and its thermal behaviour. The RF test stand, based on EPICS environment, can provide up to 2 MW peak power at 352.2 MHz in a pulse operation of 14 Hz and a duty cycle of 4.9%.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA03

About •

Received ※ 09 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 02 September 2022

Cite •

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

TUPOPA04

First Beam Matching and Transmission Studies on the ESS RFQ

414

D. Noll, R.A. Baron, C.S. Derrez, E.M. Donegani, M. Eshraqi, F. Grespan, H. Hassanzadegan, B. Jones, Y. Levinsen, N. Milas, R. Miyamoto, D.C. Plostinar, A.G. Sosa, R. Zeng
ESS, Lund, Sweden
A.C. Chauveau, O. Piquet
CEA-IRFU, Gif-sur-Yvette, France

The European Spallation Source will be driven by a 5 MW linear accelerator, producing 2.86 ms long proton beam pulses with a peak current of 62.5 mA at 14 Hz. Following the source commissioning in 2018 and 2019, the RFQ was successfully conditioned and subsequently commissioned with beam in 2021. In this paper, we will present results of studies on beam matching to the RFQ, both for low and high current beam modes, and will compare these results to model predictions.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA04

About •

Received ※ 26 August 2022 — Accepted ※ 05 September 2022 — Issue date ※ 05 September 2022

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

TUPOPA05

RFQ Performance During RF Conditioning and Beam Commissioning at ESS

418

R. Zeng, G.S. Fedel, B. Jones, R. Miyamoto, D.J.P. Nicosia, D. Noll, A.G. Sosa, A.M. Svensson, E. Trachanas
ESS, Lund, Sweden
M. Baudrier
CEA-DRF-IRFU, France
A.C. Chauveau, M.J. Desmons, P. Hamel, O. Piquet
CEA-IRFU, Gif-sur-Yvette, France
F. Grespan
INFN/LNL, Legnaro (PD), Italy

RFQ at ESS has been successfully gone through RF conditioning, RF re-conditioning and low duty cycle beam commissioning. RFQ fulfills required functions and overall performance is satisfactory. RF conditioning, three RF re-conditionings after LEBT intervention and beam commissioning will be reported and RFQ performance during these periods will be described. RFQ performance in a large extent is reflected by dynamics and interactions between RF, cavity and beam. Thanks to advanced hardware capabilities and intelligent software intelligence, observation of those dynamics and interactions are done in detailed level. Analysis of those dynamics and interaction will be introduced. Some techniques to deal with challenges resulted from those dynamics and interactions will also be discussed.

Poster TUPOPA05 [25.281 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA05

About •

Received ※ 18 August 2022 — Revised ※ 25 August 2022 — Accepted ※ 31 August 2022 — Issue date ※ 05 September 2022

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TUPOPA06

Microscopy Investigation on Different Materials After Pulsed High Field Conditioning and Low Energy H-Irradiation

422

SUPCJO06

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

C.F. Da Palma Serafim, G. Bellodi, S. Calatroni, A. Grudiev, A.M. Lombardi, R.C. Peacock, A.T. Perez Fontenla, S. Ramberger, E. Sargsyan, S. Sgobba, W. Wuensch
CERN, Meyrin, Switzerland
F. Djurabekova
HIP, University of Helsinki, Finland

During operation the LINAC4 RFQ (Radio-Frequency-Quadrupole) is exposed to high electric fields which can lead to vacuum breakdown. It is also subject to beam loss that can cause surface modification, including blistering, which can result in reduced electric field handling and an increased breakdown rate. An experimental study has been made to identify materials with high electric field capability and robustness to low-energy irradiation. In this paper we briefly discuss the selection criteria and we analyze these materials investigating their metallurgical properties using advanced microscopic techniques such as Scanning Electron Microscope, Electron Back Scattered Diffraction, Energy-dispersive X-ray Spectroscopy and conventional optical microscopy. These allow to observe and characterize the different materials on aμand a nano-scale, allowing us to compare results before and after irradiation and breakdown testing.

Poster TUPOPA06 [2.771 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA06

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Received ※ 14 August 2022 — Revised ※ 23 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 31 August 2022

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TUPOPA09

RF Measurements and Tuning of the CERN 750 MHz ELISA-RFQ for Public Exhibition

426

M. Marchi, A. Grudiev, S.J. Mathot, H.W. Pommerenke
CERN, Meyrin, Switzerland

Over the last few years CERN has successfully designed, built and commissioned the smallest RFQ to date, the one meter long PIXE-RFQ operating at 750 MHz. Its compactness offers a unique opportunity for education and public presentation of the accelerator community: A duplicate machine called ELISA-RFQ (Experimental Linac for Surface Analysis) will be exhibited in the Science Gateway, CERN’s upcoming scientific education and outreach center. It will allow the public to approach within a few centimeters a live proton beam injected into air, which is visible to the naked eye. The construction of the ELISA-RFQ has been completed in 2022. In this paper, we present the results of low-power RF measurements as well as field and frequency tuning.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA09

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Received ※ 14 August 2022 — Revised ※ 18 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 01 September 2022

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TUPOPA10

Beam Dynamics and RF Design Studies for the New RFQ for CERN Linac4 Upgrade

430

H.W. Pommerenke, G. Bellodi, A. Grudiev, S. Kumar, A.M. Lombardi
CERN, Meyrin, Switzerland

The 352 MHz Linac4-RFQ is the first rf accelerating structure of the CERN accelerator complex, accelerating an H⁻ beam to 3 MeV. After successful commissioning in 2013, superficial vane damage has been observed in 2020. In view that the RFQ is a single point of failure, in parallel to the production of a near identical spare (RFQ2), design studies on a longer-term upgrade have been launched: Linac4-RFQ3. Main goals are to achieve a design with higher beam acceptance, reduced beam losses, and reduced RF breakdown rate. Two versions of RFQ are under study: a conventional RFQ built by brazing copper, as well as an RFQ with titanium vane tips (brazed on copper). High-gradient experiments suggest that titanium vane tips support higher surface fields compared to copper, up to 40 MV/m, and are more resistant against beam irradiation. In this paper, we present beam dynamics and rfdesign of both variants of RFQ3.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA10

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Received ※ 12 August 2022 — Revised ※ 19 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 02 September 2022

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TUPOPA11

Compact Proton Accelerator in UHF Band At KAHVELab

434

SUPCGE07

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

S. Esen, A. Adiguzel, O. Kocer, S. Oz
Istanbul University, Istanbul, Turkey
A. Caglar
YTU, Istanbul, Turkey
E. Celebi, E.V. Ozcan
Bogazici University, Bebek / Istanbul, Turkey
E. Celebi
IBU, Istanbul, Turkey
A.K. Karatay, F. Yaman, Ö.H. Yilmaz
IZTECH, Izmir, Turkey
U. Kaya
Istinye University, Institute of Sciences, Istanbul, Turkey
A. Kilicgedik
Marmara University, Istanbul, Turkey
G. Türemen
Turkish Atomic Energy Authority, Ankara, Turkey
G. Unel
UCI, Irvine, California, USA

Funding: This project are supported by TUBITAK Project no: 118E838
Proton Test Beam at KahveLAB (Kandilli Detector, Accelerator and Instrumentation Laboratory) project aims to design and produce a radio frequency quadrupole (RFQ) operating at 800 MHz in Istanbul, Turkey using the local resources. The beamline consists of a proton source, a low energy beam transport (LEBT) line including the beam diagnostic section, and the RFQ cavity itself. This RFQ is a 4-vane, 1-meter-long cavity to accelerate the 20 keV beam extracted from the plasma ion source to 2 MeV. Its engineering prototype is already produced and subjected to mechanical, low-power RF, and vacuum tests. In this poster, the results of the first test production, especially the bead-pull test setup will be discussed.

Poster TUPOPA11 [16.128 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA11

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Received ※ 21 August 2022 — Revised ※ 22 August 2022 — Accepted ※ 12 September 2022 — Issue date ※ 26 September 2022

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TUPOPA12

RF Measurements and Tuning of the Test Module of 800 MHz Radio-Frequency Quadrupole

438

SUPCGE02

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

A. Kilicgedik
Marmara University, Istanbul, Turkey
A. Adiguzel, S. Esen
Istanbul University, Istanbul, Turkey
B. Baran
Ankara University, Faculty of Sciences, Ankara, Turkey
A. Caglar
YTU, Istanbul, Turkey
E. Celebi, E.V. Ozcan
Bogazici University, Bebek / Istanbul, Turkey
U. Kaya
Istinye University, Institute of Sciences, Istanbul, Turkey
G. Türemen
TENMAK-NUKEN, Ankara, Turkey
G. Unel
UCI, Irvine, California, USA
F. Yaman
IZTECH, Izmir, Turkey

Funding: This project are supported by The Scientific and Technological Research Council of Turkey (TUBITAK) Project no: 118E838
The 800 MHz RFQ (radio-frequency quadrupole), developed and built at KAHVElab (Kandilli Detector, Accelerator and Instrumentation Laboratory) at Bogazici University in Istanbul, Turkey, has been designed to provide protons that have an energy of 2 MeV within only 1 m length. The RFQ consists of two modules and the test module of RFQ was constructed. The algorithm developed by CERN, based on the measurements generated by the tuner settings estimated through the response matrix [1,2,3], has been optimized for a single module and 16 tuners. The desired field consistent with the simulation was obtained by bead pull measurements. In this study, we present low-power rf measurements and field tuning of the test module.
[1] Koubek, B., et al., PHY. REV. ACC. AND BEAMS 20,08010(2017)
[2] Koubek, B., et al., CERN-2017-0006,(2017)
[3] Pommerenke, Hermann W., et al., Nuc. Inst. and Meth. in Phy. Res. Sec.A),165564(2021)

Poster TUPOPA12 [1.699 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA12

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Received ※ 24 August 2022 — Revised ※ 27 August 2022 — Accepted ※ 31 August 2022 — Issue date ※ 02 September 2022

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TUPOPA13

Pulsed DC High Field Measurements of Irradiated and Non-Irradiated Electrodes of Different Materials

441

SUPCJO07

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R.C. Peacock, G. Burt
Lancaster University, Lancaster, United Kingdom
G. Bellodi, S. Calatroni, C.F. Da Palma Serafim, A. Grudiev, A.M. Lombardi, A.T. Perez Fontenla, S. Ramberger, E. Sargsyan, S. Sgobba, W. Wuensch
CERN, Meyrin, Switzerland

Beam loss occurs in Radio Frequency Quadrupoles (RFQ), and has been observed in the H⁻ linear accelerator Linac4 (L4) at CERN. To determine if beam loss can induce breakdowns, and to compare the robustness of different materials, tests have been done using pulsed high-voltage DC systems. Electrical breakdown phenomena and conditioning processes have been studied using these systems. Cathodes of different materials were irradiated with 1.2x10¹⁹ H⁻ p/cm², the estimated beam loss of the L4 RFQ over 10 days. The irradiated electrodes were installed in a system to observe if the irradiated area coincided with the breakdown locations, with pulsing parameters similar to the RFQ. Tests of irradiated and non-irradiated electrodes of the same material were done for comparison. The main difference observed was an increase in the number of breakdowns during the initial conditioning that returned to non-irradiated sample values with further running. Visual observations after irradiation show the beam centre and a halo the same diameter of the beam pipe. Breakdown clusters occur in the centre and halo regions, suggesting irradiation is not the only factor determining the breakdown probability.

Poster TUPOPA13 [3.845 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA13

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Received ※ 23 August 2022 — Revised ※ 29 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 07 September 2022

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TUPORI28

Injector System Development for 1 MeV/n RFQ at KOMAC

615

H.S. Kim
KAERI, Daejon, Republic of Korea
J.J. Dang, D.-H. Kim, H.-J. Kwon, S. Lee, S.P. Yun
KOMAC, KAERI, Gyeongju, Republic of Korea

Funding: This work has been supported through the KOMAC operation fund of KAERI by the Korean government (MSIT).
A Radiofrequency quadrupole (RFQ) system with 200 MHz frequency and 1 MeV/n output energy is under development at KOMAC (Korea Multi-purpose Accelerator Complex) for multiple purposes such as a test-stand for an ion source and low energy beam transport study, ion beam implantation for semiconductors and polymers and neutron generation for material study. We developed an injector system for the RFQ, which is mainly composed of a 2.45 GHz microwave ion source, low energy beam transport with two solenoids, and a vacuum system with a diagnostic chamber. The RFQ was designed to be able to accelerate the beam with 2.5 mass-to-charge ratios (A/q) but we used the proton beam for an initial test to characterize the injector system. A Detailed describtion of the constructed injector system along with test results will be given in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI28

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Received ※ 22 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 15 September 2022

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