HB2018 - List of Keywords (neutron)

Paper	Title	Other Keywords	Page
MOP1WB02	Understanding the Source and Impact of Errant Beam Loss in the Spallation Neutron Source (SNS) Super Conducting Linac (SCL)	cavity, linac, ion-source, vacuum	48
	C.C. Peters, D. Curry, G.D. Johns, T.B. Southern ORNL RAD, Oak Ridge, Tennessee, USA A.V. Aleksandrov, W. Blokland, B. Han, T.A. Justice, S.-H. Kim, M.A. Plum, A.P. Shishlo, M.P. Stockli, J.Y. Tang, R.F. Welton ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05- 00OR22725 for the U.S. Department of Energy. The Spallation Neutron Source (SNS) Linear Accelerator (Linac) delivers a high power proton beam (>1 MW) for neutron production with high neutron availability (>90%). For beam acceleration, the Linac has both normal and super conducting RF sections, with the Super Conducting Linac (SCL) portion providing the majority of beam acceleration (81 of 96 RF cavities are super conducting). Operationally, the goal is to achieve the highest possible beam energy by maximizing SCL cavity RF gradients, but not at the expense of cavity reliability. One mechanism that has negatively impacted both SCL cavity RF gradients and reliability is beam lost into the SCL due to malfunctions of upstream components. Understanding the sources and impacts of errant beam on SCL cavity performance will be discussed.
	Slides MOP1WB02 [19.080 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-MOP1WB02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP1WE03	Beam Instruments for High Power Spallation Neutron Source and Facility for ADS	target, proton, radiation, experiment	99
	S.I. Meigo JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	As increase of beam power, beam instruments play an essential role in the Hadron accelerator facility. In J-PARC, the pitting erosion on the mercury target vessel for the spallation neutron source is one of a pivotal issue to operate with the high power of the beam operation. Since the erosion is proportional to the 4th power of the beam current density, the minimization of the peak current density is required. To achieve low current density, the beam-flattening system by nonlinear beam optics using octupole magnets in J-PARC. By the present system, the peak density was successfully reduced by 30% compared to the ordinary linear optics. Also in J-PARC, transmutation experimental facility is planned for the realization of the accelerator-driven system (ADS), which will employ powerful accelerator with the beam power of 30 MW. To achieve equivalent damage on the target as the ADS, the target will be received high current density. For the continuous observation of the beam status on the target, a robust beam profile monitor is required. We have been developed beam profile monitor by using heavy-ion of Ar beam to give the damage efficiently.
	Slides TUP1WE03 [15.133 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-TUP1WE03
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP2WE02	The Beam Conditions on the Target and its Operational Impacts on Beam Intercepting Devices at European Spallation Source	target, proton, radiation, operation	110
	Y. Lee, R. Miyamoto, T.J. Shea ESS, Lund, Sweden H.D. Thomsen ISA, Aarhus, Denmark
	A large flux of spallation neutrons will be produced at the European Spallation Source (ESS) by impinging high power proton beam on the tungsten target. Until the 5 MW proton beam is stopped by the spallation target, it travels through a number of beam intercepting devices (BIDs), which include the proton beam window, a multi-wire beam profile monitor, an aperture monitor, the beam entrance window, spallation material and the target shroud. The beam-induced thermo-mechanical loads and the damage dose rate in the BIDs are largely determined by the beam energy and the beam current density. At ESS, the proton beam energy will be commissioned step-wisely, from 570 MeV towards 2 GeV. The beam current density on the BIDs in the target station is equally painted by raster beam optics. The ESS Linac and its beam optics will create rectangular beam profiles on the target with varying beam intensities. In this paper, we study the impacts of different plausible beam intensities and beam energies on the thermo-mechanical loads and radiation damage rates in the BIDs at the ESS target station.
	Slides TUP2WE02 [9.826 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-TUP2WE02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP2PO017	Study on the Leakage Fields of the Septum and Lambertson Magnets during the Beam Commissioning	septum, injection, MMI, extraction	303
	M.Y. Huang, S. Wang, S.Y. Xu IHEP, Beijing, People's Republic of China
	For China Spallation Neutron Source (CSNS), the septum magnets are the key part of the injection system and the lambertson magnet is the key part of the extraction system. If the leakage fields of the septum and lambertson magnets are large enough, the circular beam orbit of Rapid Cycling Synchrotron (RCS) would be affected. In this paper, during the beam commissioning, the leakage fields of the septum and lambertson magnets will be studied and their effects on the circular beam orbit will be given and discussed.
	Poster WEP2PO017 [0.852 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP2PO022	Study on the Phase Space Painting Injection during the Beam Commissioning for CSNS	injection, MMI, linac, dipole	309
	M.Y. Huang, S. Wang, S.Y. Xu IHEP, Beijing, People's Republic of China
	During the beam commissioning of China Spallation Neutron Source (CSNS), different injection methods were used in different periods. In the early stage, since the precise position of the injection point was unknown and the beam power was relatively small, the fixed point injection was selected. In the later period, in order to increase the beam power and reduce the beam loss, the phase space painting method was used. In this paper, the phase space painting in the horizontal and vertical planes is studied in detail and the beam commissioning results of different painting injection are given and discussed. In addition, the different injection effects of the fixed point injection and painting injection are compared and studied.
	Poster WEP2PO022 [0.708 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO022
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THA1WE04	ESS nBLM: Beam Loss Monitors based on Fast Neutron Detection	detector, linac, proton, photon	404
	T. Papaevangelou CEA/IRFU, Gif-sur-Yvette, France H. Alves, S. Aune, J. Beltramelli, Q. Bertrand, T. Bey, B. Bolzon, N. Chauvin, M. Combet, D. Desforge, M. Desmons, Y. Gauthier, E. Giner-Demange, A. Gomes, F. Gougnaud, F. Harrault, F. J. Iguaz Gutierrez, T.J. Joannem, M. Kebbiri, C. Lahonde-Hamdoun, P. Le Bourlout, Ph. Legou, O. Maillard, A. Marcel, C. Marchand, Y. Mariette, J. Marroncle, V. Nadot, M. Oublaid, G. Perreu, O. Piquet, B. Pottin, Y. Sauce, J. Schwindling, L. Segui, F. Senée, R. Touzery, G. Tsiledakis, O. Tuske, D. Uriot IRFU, CEA, University Paris-Saclay, Gif-sur-Yvette, France I. Dolenc Kittelmann, R.J. Hall-Wilton, C. Höglund, L. Robinson, T.J. Shea, P. Svensson ESS, Lund, Sweden V. Gressier IRSN, Saint-Paul-Lez-Durance, France K. Nikolopoulos Birmingham University, Birmingham, United Kingdom M. Pomorski CEA/DRT/LIST, Gif-sur-Yvette Cedex, France
	A new type of Beam Loss Monitor (BLM) system is being developed for use in the European Spallation Source (ESS) linac, primarily aiming to cover the low energy part (proton energies between 3-100 MeV). In this region of the linac, typical BLM detectors based on charged particle detection (i.e. Ionization Cham-bers) are not appropriate because the expected particle fields will be dominated by neutrons and photons. Another issue is the photon background due to the RF cavities, which is mainly due to field emission from the electrons from the cavity walls, resulting in brems-strahlung photons. The idea for the ESS neutron sensi-tive BLM system (ESS nBLM) is to use Micromegas detectors specially designed to be sensitive to fast neutrons and insensitive to low energy photons (X and gammas). In addition, the detectors must be insensitive to thermal neutrons, because those neutrons may not be directly correlated to beam losses. The appropriate configuration of the Micromegas operating conditions will allow excellent timing, intrinsic photon back-ground suppression and individual neutron counting, extending thus the dynamic range to very low particle fluxes.
	Slides THA1WE04 [3.267 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-THA1WE04
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

Understanding the Source and Impact of Errant Beam Loss in the Spallation Neutron Source (SNS) Super Conducting Linac (SCL)

cavity, linac, ion-source, vacuum

48

C.C. Peters, D. Curry, G.D. Johns, T.B. Southern
ORNL RAD, Oak Ridge, Tennessee, USA
A.V. Aleksandrov, W. Blokland, B. Han, T.A. Justice, S.-H. Kim, M.A. Plum, A.P. Shishlo, M.P. Stockli, J.Y. Tang, R.F. Welton
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05- 00OR22725 for the U.S. Department of Energy.
The Spallation Neutron Source (SNS) Linear Accelerator (Linac) delivers a high power proton beam (>1 MW) for neutron production with high neutron availability (>90%). For beam acceleration, the Linac has both normal and super conducting RF sections, with the Super Conducting Linac (SCL) portion providing the majority of beam acceleration (81 of 96 RF cavities are super conducting). Operationally, the goal is to achieve the highest possible beam energy by maximizing SCL cavity RF gradients, but not at the expense of cavity reliability. One mechanism that has negatively impacted both SCL cavity RF gradients and reliability is beam lost into the SCL due to malfunctions of upstream components. Understanding the sources and impacts of errant beam on SCL cavity performance will be discussed.

Slides MOP1WB02 [19.080 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-MOP1WB02

Export •

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

TUP1WE03

Beam Instruments for High Power Spallation Neutron Source and Facility for ADS

target, proton, radiation, experiment

99

S.I. Meigo
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

As increase of beam power, beam instruments play an essential role in the Hadron accelerator facility. In J-PARC, the pitting erosion on the mercury target vessel for the spallation neutron source is one of a pivotal issue to operate with the high power of the beam operation. Since the erosion is proportional to the 4th power of the beam current density, the minimization of the peak current density is required. To achieve low current density, the beam-flattening system by nonlinear beam optics using octupole magnets in J-PARC. By the present system, the peak density was successfully reduced by 30% compared to the ordinary linear optics. Also in J-PARC, transmutation experimental facility is planned for the realization of the accelerator-driven system (ADS), which will employ powerful accelerator with the beam power of 30 MW. To achieve equivalent damage on the target as the ADS, the target will be received high current density. For the continuous observation of the beam status on the target, a robust beam profile monitor is required. We have been developed beam profile monitor by using heavy-ion of Ar beam to give the damage efficiently.

Slides TUP1WE03 [15.133 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-TUP1WE03

Export •

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

TUP2WE02

The Beam Conditions on the Target and its Operational Impacts on Beam Intercepting Devices at European Spallation Source

target, proton, radiation, operation

110

Y. Lee, R. Miyamoto, T.J. Shea
ESS, Lund, Sweden
H.D. Thomsen
ISA, Aarhus, Denmark

A large flux of spallation neutrons will be produced at the European Spallation Source (ESS) by impinging high power proton beam on the tungsten target. Until the 5 MW proton beam is stopped by the spallation target, it travels through a number of beam intercepting devices (BIDs), which include the proton beam window, a multi-wire beam profile monitor, an aperture monitor, the beam entrance window, spallation material and the target shroud. The beam-induced thermo-mechanical loads and the damage dose rate in the BIDs are largely determined by the beam energy and the beam current density. At ESS, the proton beam energy will be commissioned step-wisely, from 570 MeV towards 2 GeV. The beam current density on the BIDs in the target station is equally painted by raster beam optics. The ESS Linac and its beam optics will create rectangular beam profiles on the target with varying beam intensities. In this paper, we study the impacts of different plausible beam intensities and beam energies on the thermo-mechanical loads and radiation damage rates in the BIDs at the ESS target station.

Slides TUP2WE02 [9.826 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-TUP2WE02

Export •

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

WEP2PO017

Study on the Leakage Fields of the Septum and Lambertson Magnets during the Beam Commissioning

septum, injection, MMI, extraction

303

M.Y. Huang, S. Wang, S.Y. Xu
IHEP, Beijing, People's Republic of China

For China Spallation Neutron Source (CSNS), the septum magnets are the key part of the injection system and the lambertson magnet is the key part of the extraction system. If the leakage fields of the septum and lambertson magnets are large enough, the circular beam orbit of Rapid Cycling Synchrotron (RCS) would be affected. In this paper, during the beam commissioning, the leakage fields of the septum and lambertson magnets will be studied and their effects on the circular beam orbit will be given and discussed.

Poster WEP2PO017 [0.852 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO017

Export •

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

WEP2PO022

Study on the Phase Space Painting Injection during the Beam Commissioning for CSNS

injection, MMI, linac, dipole

309

M.Y. Huang, S. Wang, S.Y. Xu
IHEP, Beijing, People's Republic of China

During the beam commissioning of China Spallation Neutron Source (CSNS), different injection methods were used in different periods. In the early stage, since the precise position of the injection point was unknown and the beam power was relatively small, the fixed point injection was selected. In the later period, in order to increase the beam power and reduce the beam loss, the phase space painting method was used. In this paper, the phase space painting in the horizontal and vertical planes is studied in detail and the beam commissioning results of different painting injection are given and discussed. In addition, the different injection effects of the fixed point injection and painting injection are compared and studied.

Poster WEP2PO022 [0.708 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO022

Export •

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

THA1WE04

ESS nBLM: Beam Loss Monitors based on Fast Neutron Detection

detector, linac, proton, photon

404

T. Papaevangelou
CEA/IRFU, Gif-sur-Yvette, France
H. Alves, S. Aune, J. Beltramelli, Q. Bertrand, T. Bey, B. Bolzon, N. Chauvin, M. Combet, D. Desforge, M. Desmons, Y. Gauthier, E. Giner-Demange, A. Gomes, F. Gougnaud, F. Harrault, F. J. Iguaz Gutierrez, T.J. Joannem, M. Kebbiri, C. Lahonde-Hamdoun, P. Le Bourlout, Ph. Legou, O. Maillard, A. Marcel, C. Marchand, Y. Mariette, J. Marroncle, V. Nadot, M. Oublaid, G. Perreu, O. Piquet, B. Pottin, Y. Sauce, J. Schwindling, L. Segui, F. Senée, R. Touzery, G. Tsiledakis, O. Tuske, D. Uriot
IRFU, CEA, University Paris-Saclay, Gif-sur-Yvette, France
I. Dolenc Kittelmann, R.J. Hall-Wilton, C. Höglund, L. Robinson, T.J. Shea, P. Svensson
ESS, Lund, Sweden
V. Gressier
IRSN, Saint-Paul-Lez-Durance, France
K. Nikolopoulos
Birmingham University, Birmingham, United Kingdom
M. Pomorski
CEA/DRT/LIST, Gif-sur-Yvette Cedex, France

A new type of Beam Loss Monitor (BLM) system is being developed for use in the European Spallation Source (ESS) linac, primarily aiming to cover the low energy part (proton energies between 3-100 MeV). In this region of the linac, typical BLM detectors based on charged particle detection (i.e. Ionization Cham-bers) are not appropriate because the expected particle fields will be dominated by neutrons and photons. Another issue is the photon background due to the RF cavities, which is mainly due to field emission from the electrons from the cavity walls, resulting in brems-strahlung photons. The idea for the ESS neutron sensi-tive BLM system (ESS nBLM) is to use Micromegas detectors specially designed to be sensitive to fast neutrons and insensitive to low energy photons (X and gammas). In addition, the detectors must be insensitive to thermal neutrons, because those neutrons may not be directly correlated to beam losses. The appropriate configuration of the Micromegas operating conditions will allow excellent timing, intrinsic photon back-ground suppression and individual neutron counting, extending thus the dynamic range to very low particle fluxes.

Slides THA1WE04 [3.267 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-THA1WE04

Export •

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