IPAC2015 - List of Keywords (closed-orbit)

Paper	Title	Other Keywords	Page
MOPWA035	Two General Orbit Theorems for Efficient Measurements of Beam Optics	storage-ring, optics, dipole, lattice	183
	B. Riemann, A. Ferrarotto, P. Hartmann, B.D. Isbarn, S. Koetter, M. Sommer, P. Towalski, T. Weis DELTA, Dortmund, Germany
	Closed-orbit perturbations and oscillating beam solutions in storage rings are closely related. While techniques exist to fit accelerator models to closed-orbit perturbations or to oscillation data, the exploitation of their relation has been limited. In this work, two orbit theorems that allow an efficient computation of optical parameters in storage rings with older hardware are derived for coupled linear beam motion. The monitor theorem is based on an uncoupled case study described by the author in an earlier work and has been generalized as well as simplified in mathematical abstraction to provide a reliable and computationally stable framework for beam optics measurements. It is based on a closed-orbit measurement utilizing 4 dipole correctors (2 for each plane). The corrector theorem allows to obtain parameters of these dipole correctors using two turn-by-turn monitors at almost arbitrary positions in the ring (which do not need to be located in a drift space), so that it is possible to uniquely resolve closed orbits into optical parameters without sophisticated lattice models.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA035
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MOPJE033	Coupled Orbit Response Coefficients with Constant Revolution Time	storage-ring, optics, radio-frequency, diagnostics	354
	V.G. Ziemann Uppsala University, Uppsala, Sweden
	We calculate orbit response coefficients for arbitrarily coupled lattice which keep the orbit length constant as is needed to maintain synchronicity with a radio-frequency system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE033
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MOPJE063	Orbit Correction in the CERN PS Booster	quadrupole, alignment, dipole, booster	449
	M. McAteer, E. Benedetto, C. Carli, G.P. Di Giovanni, B. Mikulec, R. Tomás CERN, Geneva, Switzerland
	Funding: This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no (PITN-GA-2011-289485-OPAC). Prior to the Long Shutdown of 2013-2014 (LS1), control of the closed orbit in the four rings of the CERN PS Booster (PSB) was achieved by adjusting the alignment of several focusing quadrupoles. After a set of orbit corrector dipoles was installed, a major realignment campaign was undertaken to remove these intentional quadrupole offsets and any other magnet misalignments. This paper summarizes the effects of the magnet realignment on the closed orbit in the PSB and the results of closed orbit correction with corrector dipoles.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE063
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MOPJE077	Progress on Simulation of Fixed Field Alternating Gradient Accelerators	simulation, betatron, experiment, acceleration	495
	S.L. Sheehy JAI, Oxford, United Kingdom A. Adelmann PSI, Villigen PSI, Switzerland M. Haj Tahar, F. Méot BNL, Upton, Long Island, New York, USA Y. Ishi, Y. Kuriyama, Y. Mori, M. Sakamoto, T. Uesugi Kyoto University, Research Reactor Institute, Osaka, Japan D.J. Kelliher, S. Machida, C.R. Prior, C.T. Rogers STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	Fixed Field Alternating Gradient accelerators have been realised in recent decades thanks partly to computational power, enabling detailed design and simulation prior to construction. We review the specific challenges of these machines and the range of different codes used to model them including ZGOUBI, OPAL and a number of in-house codes from different institutes. The current status of benchmarking between codes is presented and compared to the results of recent characterisation experiments with a 150 MeV FFAG at KURRI in Japan. Finally, we outline plans toward ever more realistic simulations including space charge, material interactions and more detailed models of various components.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE077
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MOPMA010	Commissioning Simulations for the APS Upgrade Lattice	lattice, simulation, coupling, quadrupole	553
	V. Sajaev, M. Borland ANL, Argonne, Ilinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. A hybrid seven-bend-achromat lattice has been proposed for the APS upgrade that will feature very strong focusing elements and relatively small vacuum chamber. Achieving design lattice parameters during commissioning will need to be accomplished in a short period of time to minimize dark time for APS users. We describe here start-to-end simulation of the machine commissioning beginning from first-turn trajectory correction, performing orbit and lattice correction, and finally evaluating nonlinear performance of the corrected lattice in terms of dynamic aperture and lifetime.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMA010
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MOPMN025	Local Impedance Estimation of NSLS-II Storage Ring with Bumped Orbit	impedance, wiggler, damping, vacuum	754
	J. Choi, G. Bassi, A. Blednykh, Y. Hidaka BNL, Upton, Long Island, New York, USA
	Funding: DOE contract No: DE-AC02- 98CH10886 As the newly constructed 3rd generation light source, NSLS-II is expected to provide the synchrotron radiation of ultra high brightness and flux with advanced insertion devices. To minimize the beam emittance, damping wigglers are used and the small aperture is located at the straight section with the damping wiggler and the corresponding vacuum camber is NEG coated. We used the local bump method to find the effect on the beam from the narrow aperture and the paper shows the results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMN025
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MOPMN030	Proton Spin Tracking with Symplectic Integration of Orbit Motion	proton, resonance, ion, sextupole	766
	Y. Luo, Y. Dutheil, H. Huang, F. Méot, V.H. Ranjbar BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Symplectic integration for orbital motion had been adopted in SimTrack which has been extensively used for dynamic aperture calculation with beam-beam interaction for the Relativistic Heavy Ion Collider (RHIC). Recently spin tracking for protons has been implemented on top of the orbit motion in this code. In this article, we will explain the implementation of spin motion using Thomas-BMT equation, and benchmark with other spin tracking codes currently used for RHIC. Possibility and remedy for very-long term particle tracking, such as on the RHIC energy acceleration, is also explored.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPMN030
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MOPHA014	Magnetic Field Parametrization for Efficient Spin Tracking with POLE	lattice, resonance, quadrupole, simulation	808
	J.F. Schmidt, W. Hillert ELSA, Bonn, Germany
	Funding: BMBF The new spin dynamics simulation suite pole is designed to perform systematic studies of beam depolarization in circular accelerators with short storage times or fast energy ramps. It is based on spin tracking using a Runge-Kutta algorithm with adaptive step width. pole can approximate the magnetic fields of the accelerator with a Fourier series to reduce computing time. Therefore, the magnetic field distribution is simplified with frequency filters by a C++ library before the spin tracking. The versatile library deals with import and export of lattices and particle trajectories from MAD-X and Elegant. The derived magnetic field distributions can be interpolated, Fourier transformed and accessed easily by applications. This contribution discusses advantages and disadvantages of the frquency filtering concept.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA014
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MOPHA058	Beam Based Gain Calibration for Beam Position Monitor at J-PARC Main Ring	simulation, operation, synchrotron, proton	927
	H. Kuboki, J. Takano, M. Tejima, T. Toyama KEK, Ibaraki, Japan S. Hatakeyama JAEA/J-PARC, Tokai-mura, Japan
	Funding: MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled "Unification and Development of the Neutrino Science Frontier" Beam Position Monitor (BPM) is one of the essential elements in a synchrotron facility. It provides the accurate beam positions, which are used to correct the closed orbit distortion. Each BPM is installed with the electronics which enable to acquire the data of the turn-by-turn beam positions. Here, we define the "gain" as the proportionality coefficient between the signal detected at the ADC and the ideal signal without any errors. The signal strength from a BPM electrode varies depending on 1) transmission characteristics of a long cable, 2) processing circuit, and 3) contact resistance at the connected parts. These are the origin of the gain deviations. In order to correct the deviations, a Beam Based Gain Calibration (BBGC) method has been proposed . Development of a new method for adequate gain calibration is required because any calibration method for routine operation has not been established for BPMs with diagonal-cut electrodes used at J-PARC Main Ring. The results of analysis will be presented using the Total Least Square fitting as an adequate method for the BBGC with sufficient accuracy within 0.6% in one standard deviation. M. Tejima et al., DIPAC2011 (2011).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA058
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TUPTY012	Orbit Correction in CEPC	quadrupole, dipole, factory, target	2022
	S. Bai, J. Gao, H. Geng IHEP, Beijing, People's Republic of China
	With the discovery of the higgs boson at around 125GeV, a circular higgs factory design with high luminosity (L ~ 10³⁴ cm^-2s^-1) is becoming more popular in the accelerator world. The CEPC project in China is one of them. To reduce the cost, pretzel scheme was considered in CEPC orbit design. The presence of every kind of errors and misalignments will destroy the pretzel orbit. In this paper, we correct the distorted pretzel orbit in the CEPC main ring using the dipole correctors and beam position monitors. The pretzel orbit was recovered and the maximum corrector strengths are got.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY012
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WEPWA043	Progress on the Design of the Racetrack FFAG Decay Ring for nuSTORM	lattice, factory, detector, resonance	2594
	J.-B. Lagrange, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom R.B. Appleby, J.M. Garland, H.L. Owen, S.C. Tygier UMAN, Manchester, United Kingdom R.B. Appleby Cockcroft Institute, Warrington, Cheshire, United Kingdom Y. Mori Kyoto University, Research Reactor Institute, Osaka, Japan
	The neutrino beam produced from muons decaying in a storage ring would be an ideal tool for precise neutrino cross section measurements and search for sterile neutrinos due to its precisely known flavour content and spectrum. In the proposed nuSTORM facility pions would be directly injected into a storage ring, where circulating muon beam would be captured. The racetrack FFAG (Fixed Field Alternating Gradient) option for nuSTORM decay ring offers a very good performance due to a large dynamic and momentum acceptance. Machine parameters, linear optics design, beam dynamics and injection system for nuSTORM FFAG ring are discussed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA043
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THPF037	Upgrade of the LNS Superconducting Cyclotron	extraction, ion, cyclotron, experiment	3779
	A. Calanna, L. Calabretta, G. Cuttone, G. Dagostino, D. Rifuggiato INFN/LNS, Catania, Italy M. Maggiore INFN/LNL, Legnaro (PD), Italy A. Radovinsky MIT/PSFC, Cambridge, Massachusetts, USA
	The superconducting cyclotron of the LNS-INFN has been working for about 20 years delivering ion beams from proton to gold in the wide energy range from 15 AMeV to 80 AMeV. The beam extraction is performed by means of two electrostatic deflectors and a set of magnetic channels. Recently, the experiment NUMEN has been proposed to study the nuclear matrix element for the double beta decay . The requirements on target are light ion beams (A<30), with an energy range of 15-60 AMeV and a beam power of 1-5 kW. To achieve this goal we have studied the feasibility of extraction by stripping through the existing extraction channel with an increased transversal section. In addition, a new extraction channel has been designed to increase as much as possible the number of the extracted ions and energies. To allow the realization of these new channels, a new superconducting magnet is needed. The major changes and the expected performances for the upgraded cyclotron, as well as the state-of-art of the design, are here presented.
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THPF087	New Shaving Scheme for Low-Intensity Beams in the CERN PS Booster and Feasibility at 160 MeV	emittance, booster, simulation, operation	3893
	M. Kowalska, E. Benedetto, V. Forte, B. Mikulec, G. Rumolo CERN, Geneva, Switzerland V. Forte Université Blaise Pascal, Clermont-Ferrand, France M. Kowalska EPFL, Lausanne, Switzerland
	The PS Booster is the first synchrotron in the CERN proton accelerator chain, serving all downstream machines. As part of the LHC Injector Upgrade Project, the PSB injection energy will increase from 50 MeV to 160 MeV and a new H⁻ charge-exchange injection scheme will be implemented. Beam losses are a concern due to the increased injection energy, and mitigation scenarios are under investigation. On the other hand it is desirable for low-intensity beams to have the possibility to precisely tailor sub-micron beam emittances through controlled scraping (transverse shaving process) towards a suitable aperture restriction. Challenges are the higher activation potential of the beam and the smaller transverse beam sizes around 160 MeV as compared to 63 MeV, at which the shaving is presently done. This paper describes the proposal of a new shaving scheme, more robust with respect to the steering errors and the choice of the working point, which localizes the scraping losses on the main PS Booster aperture restriction. The robustness of the new method, together with the results of simulations and measurements are discussed for the current (50 MeV) and future (160 MeV) situation.
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THPF118	Fermilab Booster Injection Upgrade to 800 MeV for PIP-II	injection, booster, dipole, linac	3986
	D.E. Johnson, V.A. Lebedev, I.L. Rakhno Fermilab, Batavia, Illinois, USA
	Fermilab is proposing to build an 800 MeV superconducting linac which will be used to inject H⁻ ions into the existing Booster synchrotron as part of the proposed PIP-II project. The injection energy of the Booster will be raised from the current 400 MeV to 800 MeV. Transverse phase space painting will be required due to the small linac transverse emittance (emit_ring/emit_linac ~ 10) and low average linac current of 2 mA. The painting is also helpful with reduction of beam distributions resulting in a reduction of space charge effects. The injection will require approximately 300 turns corresponding to a ~ 0.5 ms injection time. A factor of seven increase in injected beam power (relative to present operation) requires an injection waste beam absorber. The paper describes the requirements for the injection insert, itsdesign, and plans for transverse painting.
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Paper

Title

Other Keywords

Page

MOPWA035

Two General Orbit Theorems for Efficient Measurements of Beam Optics

storage-ring, optics, dipole, lattice

183

B. Riemann, A. Ferrarotto, P. Hartmann, B.D. Isbarn, S. Koetter, M. Sommer, P. Towalski, T. Weis
DELTA, Dortmund, Germany

Closed-orbit perturbations and oscillating beam solutions in storage rings are closely related. While techniques exist to fit accelerator models to closed-orbit perturbations or to oscillation data, the exploitation of their relation has been limited. In this work, two orbit theorems that allow an efficient computation of optical parameters in storage rings with older hardware are derived for coupled linear beam motion. The monitor theorem is based on an uncoupled case study described by the author in an earlier work and has been generalized as well as simplified in mathematical abstraction to provide a reliable and computationally stable framework for beam optics measurements. It is based on a closed-orbit measurement utilizing 4 dipole correctors (2 for each plane). The corrector theorem allows to obtain parameters of these dipole correctors using two turn-by-turn monitors at almost arbitrary positions in the ring (which do not need to be located in a drift space), so that it is possible to uniquely resolve closed orbits into optical parameters without sophisticated lattice models.

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MOPJE033

Coupled Orbit Response Coefficients with Constant Revolution Time

storage-ring, optics, radio-frequency, diagnostics

354

V.G. Ziemann
Uppsala University, Uppsala, Sweden

We calculate orbit response coefficients for arbitrarily coupled lattice which keep the orbit length constant as is needed to maintain synchronicity with a radio-frequency system.

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MOPJE063

Orbit Correction in the CERN PS Booster

quadrupole, alignment, dipole, booster

449

M. McAteer, E. Benedetto, C. Carli, G.P. Di Giovanni, B. Mikulec, R. Tomás
CERN, Geneva, Switzerland

Funding: This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no (PITN-GA-2011-289485-OPAC).
Prior to the Long Shutdown of 2013-2014 (LS1), control of the closed orbit in the four rings of the CERN PS Booster (PSB) was achieved by adjusting the alignment of several focusing quadrupoles. After a set of orbit corrector dipoles was installed, a major realignment campaign was undertaken to remove these intentional quadrupole offsets and any other magnet misalignments. This paper summarizes the effects of the magnet realignment on the closed orbit in the PSB and the results of closed orbit correction with corrector dipoles.

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MOPJE077

Progress on Simulation of Fixed Field Alternating Gradient Accelerators

simulation, betatron, experiment, acceleration

495

S.L. Sheehy
JAI, Oxford, United Kingdom
A. Adelmann
PSI, Villigen PSI, Switzerland
M. Haj Tahar, F. Méot
BNL, Upton, Long Island, New York, USA
Y. Ishi, Y. Kuriyama, Y. Mori, M. Sakamoto, T. Uesugi
Kyoto University, Research Reactor Institute, Osaka, Japan
D.J. Kelliher, S. Machida, C.R. Prior, C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

Fixed Field Alternating Gradient accelerators have been realised in recent decades thanks partly to computational power, enabling detailed design and simulation prior to construction. We review the specific challenges of these machines and the range of different codes used to model them including ZGOUBI, OPAL and a number of in-house codes from different institutes. The current status of benchmarking between codes is presented and compared to the results of recent characterisation experiments with a 150 MeV FFAG at KURRI in Japan. Finally, we outline plans toward ever more realistic simulations including space charge, material interactions and more detailed models of various components.

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MOPMA010

Commissioning Simulations for the APS Upgrade Lattice

lattice, simulation, coupling, quadrupole

553

V. Sajaev, M. Borland
ANL, Argonne, Ilinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
A hybrid seven-bend-achromat lattice has been proposed for the APS upgrade that will feature very strong focusing elements and relatively small vacuum chamber. Achieving design lattice parameters during commissioning will need to be accomplished in a short period of time to minimize dark time for APS users. We describe here start-to-end simulation of the machine commissioning beginning from first-turn trajectory correction, performing orbit and lattice correction, and finally evaluating nonlinear performance of the corrected lattice in terms of dynamic aperture and lifetime.

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MOPMN025

Local Impedance Estimation of NSLS-II Storage Ring with Bumped Orbit

impedance, wiggler, damping, vacuum

754

J. Choi, G. Bassi, A. Blednykh, Y. Hidaka
BNL, Upton, Long Island, New York, USA

Funding: DOE contract No: DE-AC02- 98CH10886
As the newly constructed 3rd generation light source, NSLS-II is expected to provide the synchrotron radiation of ultra high brightness and flux with advanced insertion devices. To minimize the beam emittance, damping wigglers are used and the small aperture is located at the straight section with the damping wiggler and the corresponding vacuum camber is NEG coated. We used the local bump method to find the effect on the beam from the narrow aperture and the paper shows the results.

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MOPMN030

Proton Spin Tracking with Symplectic Integration of Orbit Motion

proton, resonance, ion, sextupole

766

Y. Luo, Y. Dutheil, H. Huang, F. Méot, V.H. Ranjbar
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Symplectic integration for orbital motion had been adopted in SimTrack which has been extensively used for dynamic aperture calculation with beam-beam interaction for the Relativistic Heavy Ion Collider (RHIC). Recently spin tracking for protons has been implemented on top of the orbit motion in this code. In this article, we will explain the implementation of spin motion using Thomas-BMT equation, and benchmark with other spin tracking codes currently used for RHIC. Possibility and remedy for very-long term particle tracking, such as on the RHIC energy acceleration, is also explored.

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MOPHA014

Magnetic Field Parametrization for Efficient Spin Tracking with POLE

lattice, resonance, quadrupole, simulation

808

J.F. Schmidt, W. Hillert
ELSA, Bonn, Germany

Funding: BMBF
The new spin dynamics simulation suite pole is designed to perform systematic studies of beam depolarization in circular accelerators with short storage times or fast energy ramps. It is based on spin tracking using a Runge-Kutta algorithm with adaptive step width. pole can approximate the magnetic fields of the accelerator with a Fourier series to reduce computing time. Therefore, the magnetic field distribution is simplified with frequency filters by a C++ library before the spin tracking. The versatile library deals with import and export of lattices and particle trajectories from MAD-X and Elegant. The derived magnetic field distributions can be interpolated, Fourier transformed and accessed easily by applications. This contribution discusses advantages and disadvantages of the frquency filtering concept.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA014

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MOPHA058

Beam Based Gain Calibration for Beam Position Monitor at J-PARC Main Ring

simulation, operation, synchrotron, proton

927

H. Kuboki, J. Takano, M. Tejima, T. Toyama
KEK, Ibaraki, Japan
S. Hatakeyama
JAEA/J-PARC, Tokai-mura, Japan

Funding: MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled "Unification and Development of the Neutrino Science Frontier"
Beam Position Monitor (BPM) is one of the essential elements in a synchrotron facility. It provides the accurate beam positions, which are used to correct the closed orbit distortion. Each BPM is installed with the electronics which enable to acquire the data of the turn-by-turn beam positions. Here, we define the "gain" as the proportionality coefficient between the signal detected at the ADC and the ideal signal without any errors. The signal strength from a BPM electrode varies depending on 1) transmission characteristics of a long cable, 2) processing circuit, and 3) contact resistance at the connected parts. These are the origin of the gain deviations. In order to correct the deviations, a Beam Based Gain Calibration (BBGC) method has been proposed *. Development of a new method for adequate gain calibration is required because any calibration method for routine operation has not been established for BPMs with diagonal-cut electrodes used at J-PARC Main Ring. The results of analysis will be presented using the Total Least Square fitting as an adequate method for the BBGC with sufficient accuracy within 0.6% in one standard deviation.
* M. Tejima et al., DIPAC2011 (2011).

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TUPTY012

Orbit Correction in CEPC

quadrupole, dipole, factory, target

2022

S. Bai, J. Gao, H. Geng
IHEP, Beijing, People's Republic of China

With the discovery of the higgs boson at around 125GeV, a circular higgs factory design with high luminosity (L ~ 10³⁴ cm^-2s^-1) is becoming more popular in the accelerator world. The CEPC project in China is one of them. To reduce the cost, pretzel scheme was considered in CEPC orbit design. The presence of every kind of errors and misalignments will destroy the pretzel orbit. In this paper, we correct the distorted pretzel orbit in the CEPC main ring using the dipole correctors and beam position monitors. The pretzel orbit was recovered and the maximum corrector strengths are got.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY012

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WEPWA043

Progress on the Design of the Racetrack FFAG Decay Ring for nuSTORM

lattice, factory, detector, resonance

2594

J.-B. Lagrange, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
R.B. Appleby, J.M. Garland, H.L. Owen, S.C. Tygier
UMAN, Manchester, United Kingdom
R.B. Appleby
Cockcroft Institute, Warrington, Cheshire, United Kingdom
Y. Mori
Kyoto University, Research Reactor Institute, Osaka, Japan

The neutrino beam produced from muons decaying in a storage ring would be an ideal tool for precise neutrino cross section measurements and search for sterile neutrinos due to its precisely known flavour content and spectrum. In the proposed nuSTORM facility pions would be directly injected into a storage ring, where circulating muon beam would be captured. The racetrack FFAG (Fixed Field Alternating Gradient) option for nuSTORM decay ring offers a very good performance due to a large dynamic and momentum acceptance. Machine parameters, linear optics design, beam dynamics and injection system for nuSTORM FFAG ring are discussed in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA043

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THPF037

Upgrade of the LNS Superconducting Cyclotron

extraction, ion, cyclotron, experiment

3779

A. Calanna, L. Calabretta, G. Cuttone, G. Dagostino, D. Rifuggiato
INFN/LNS, Catania, Italy
M. Maggiore
INFN/LNL, Legnaro (PD), Italy
A. Radovinsky
MIT/PSFC, Cambridge, Massachusetts, USA

The superconducting cyclotron of the LNS-INFN has been working for about 20 years delivering ion beams from proton to gold in the wide energy range from 15 AMeV to 80 AMeV. The beam extraction is performed by means of two electrostatic deflectors and a set of magnetic channels. Recently, the experiment NUMEN has been proposed to study the nuclear matrix element for the double beta decay . The requirements on target are light ion beams (A<30), with an energy range of 15-60 AMeV and a beam power of 1-5 kW. To achieve this goal we have studied the feasibility of extraction by stripping through the existing extraction channel with an increased transversal section. In addition, a new extraction channel has been designed to increase as much as possible the number of the extracted ions and energies. To allow the realization of these new channels, a new superconducting magnet is needed. The major changes and the expected performances for the upgraded cyclotron, as well as the state-of-art of the design, are here presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF037

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THPF087

New Shaving Scheme for Low-Intensity Beams in the CERN PS Booster and Feasibility at 160 MeV

emittance, booster, simulation, operation

3893

M. Kowalska, E. Benedetto, V. Forte, B. Mikulec, G. Rumolo
CERN, Geneva, Switzerland
V. Forte
Université Blaise Pascal, Clermont-Ferrand, France
M. Kowalska
EPFL, Lausanne, Switzerland

The PS Booster is the first synchrotron in the CERN proton accelerator chain, serving all downstream machines. As part of the LHC Injector Upgrade Project, the PSB injection energy will increase from 50 MeV to 160 MeV and a new H⁻ charge-exchange injection scheme will be implemented. Beam losses are a concern due to the increased injection energy, and mitigation scenarios are under investigation. On the other hand it is desirable for low-intensity beams to have the possibility to precisely tailor sub-micron beam emittances through controlled scraping (transverse shaving process) towards a suitable aperture restriction. Challenges are the higher activation potential of the beam and the smaller transverse beam sizes around 160 MeV as compared to 63 MeV, at which the shaving is presently done. This paper describes the proposal of a new shaving scheme, more robust with respect to the steering errors and the choice of the working point, which localizes the scraping losses on the main PS Booster aperture restriction. The robustness of the new method, together with the results of simulations and measurements are discussed for the current (50 MeV) and future (160 MeV) situation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF087

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THPF118

Fermilab Booster Injection Upgrade to 800 MeV for PIP-II

injection, booster, dipole, linac

3986

D.E. Johnson, V.A. Lebedev, I.L. Rakhno
Fermilab, Batavia, Illinois, USA

Fermilab is proposing to build an 800 MeV superconducting linac which will be used to inject H⁻ ions into the existing Booster synchrotron as part of the proposed PIP-II project. The injection energy of the Booster will be raised from the current 400 MeV to 800 MeV. Transverse phase space painting will be required due to the small linac transverse emittance (emit_ring/emit_linac ~ 10) and low average linac current of 2 mA. The painting is also helpful with reduction of beam distributions resulting in a reduction of space charge effects. The injection will require approximately 300 turns corresponding to a ~ 0.5 ms injection time. A factor of seven increase in injected beam power (relative to present operation) requires an injection waste beam absorber. The paper describes the requirements for the injection insert, itsdesign, and plans for transverse painting.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF118

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