PAC2013 - List of Authors (Solyak, N.)

Paper

Title

Page

Status and Opportunities at Project X: A Multi-MW Facility for Intensity Frontier Research

315

S.D. Holmes, M. Kaducak, R.D. Kephart, I. Kourbanis, V.A. Lebedev, C.S. Mishra, S. Nagaitsev, N. Solyak, R.S. Tschirhart
Fermilab, Batavia, USA

Funding: Work supported by the Fermi Research Alliance under U.S. Department of Energy contract number DE-AC02-07CH11359
Project X is a high intensity proton facility that will support a world-leading U.S. program in Intensity Frontier physics over the next several decades. Project X is currently under development by Fermilab in collaboration with national and international partners. Project X will be unique in its ability to deliver, simultaneously, up to 6 MW of site-wide beam power to multiple experiments, at energies ranging from 235 MeV to 120 GeV, and with flexible and independently controlled beam time patterns. Project X will support a wide range of experiments utilizing neutrino, muon, kaon, nucleon, and atomic probes [1,2]. In addition, Project X will lay the foundation for the long-term development of a Neutrino Factory and/or Muon Collider.

MOPMA10

Studies of Fault Scenarios in SC CW Project-X Linac

318

A. Saini, J.-F. Ostiguy, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

The success of Project-X accelerator facility crucially depends on reliable operation of 1 GeV superconducting (SC) continuous wave (CW) linac at first stage. Operation at high intensity in CW mode puts stringent tolerances on beamline elements. Any fault scenario that affects nominal operation of beamline elements results in beam mismatch with subsequent sections. This in turn leads to emittance growth, and ultimately triggers beam losses. In worst case, it could affect the reliability of the machine and long downtime may be needed to replace the faulty elements. In order to reduce beam interruptions, a robust lattice design is required which can allow local retuning to make the machine operable in such scenarios. This paper presents studies performed to understand the consequences of failure of various beamline elements and discusses outcome of local retuning for different fault scenarios at critical locations in linac.

MOPMA12

Design Issues of High Intensity SC CW Ion Linac for Project-X facility

321

A. Saini, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

Project-X is a high intensity proton facility which is primarily based on superconducting (SC) continuous wave (CW) linac. One of the most challenging tasks of Project-X facility is to have robust design of SC CW linac which can provide high quality beam to several experiments and subsequent pulsed linac simultaneously. Among the various technical problems associated with the SC CW linac, halo formation, beam mismatch, uncontrolled emittance growth and beam losses are the most crucial as they can limit overall performance and reliability. Scope of this paper is to address these issues for reference design of Project-X SC CW linac.

MOPMA13

Layout of Project-X Facility: A Reference Design

324

A. Saini, J.-P. Carneiro, D.E. Johnson, J.-F. Ostiguy, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

Project-X is a proposed high intensity proton facility to be built at Fermilab. It will be a multi-user facility which can support several experiments simultaneously. In the current scenario, Project-X facility would be built in three stages. Each stage is associated with compelling scientific programs and in synergy with Fermilab infrastructure. This paper will present reference design of Project-X accelerator facility and discuss main motivations and requirements resulting in this layout and beam optics.

TUYAA1

The Project-X Injector Experiment: A Novel High Performance Front-end for a Future High Power Proton Facility at Fermilab

374

S. Nagaitsev, S.D. Holmes, D.E. Johnson, M. Kaducak, R.D. Kephart, V.A. Lebedev, C.S. Mishra, A.V. Shemyakin, N. Solyak, R.P. Stanek, V.P. Yakovlev
Fermilab, Batavia, USA
D. Li
LBNL, Berkeley, California, USA
S. Malhotra, M.M. Pande, P. Singh
BARC, Mumbai, India
P.N. Ostroumov
ANL, Argonne, USA

This presentation should describe the Project X Injector Experiment (PXIE)and its connection with Project X. It should focus on the novel aspects of PXIE, namely the programmable, bunch-by-bunch chopping of a CW H⁻ beam; acceleration in CW superconducting RF structures immediately following the RFQ; operation of SRF structures adjacent to a high-power chopper target; and preservation of high-quality chopped beams with acceptable emittance growth and halo.

Slides TUYAA1 [8.806 MB]

TUODB2

Longitudinal Beam Dynamics and LLRF Requirements for the Project X Pulsed Linac

439

A. Vivoli, G.I. Cancelo, B. Chase, N. Solyak, P. Varghese
Fermilab, Batavia, USA

Project X is a high intensity proton facility being developed to support the intensity frontier physics program over the next two decades at Fermilab. The Reference Design is based on a continuous wave (CW) superconducting 3 GeV linac providing up to 1 and 3 MW of beam power at 1 and 3 GeV respectively, while a superconducting pulsed linac provides acceleration of roughly 4.3% of the beam delivered from the CW linac to the 8 GeV injection energy of the existing Recycler/Main Injector complex. In this paper we present the results of simulation of longitudinal beam dynamics and Low Level RF (LLRF) control system in the pulsed linac, operated for long pulses in presence of errors and cavity detuning for different RF configurations and settings, and set the requirements for the LLRF necessary to fulfill the specifications of the design.

Slides TUODB2 [8.618 MB]

TUPBA12

Design of the ILC RTML Extraction Lines for the Renovated Two-stage Bunch Compressor

550

S. Seletskiy
BNL, Upton, Long Island, New York, USA
N. Solyak
Fermilab, Batavia, USA

The renovated two-stage bunch compressor (BC) in the International Linear Collider Damping Ring to the Main Linac beamline requires new design for the extraction lines (EL). The ELs located downstream of each stage of the BC will be used for both an emergency abort dumping of the beam and the tune-up continuous train-by-train extraction. They must accept both compressed and uncompressed beam with energy spread of 1.4% and 0.1% respectively. In this paper we report the design that allowed minimizing the length of such extraction lines while offsetting the beam dumps from the main line by 5m distance required for acceptable radiation level in the service tunnel. Proposed extraction lines can accommodate beams with different energy spreads at the same time providing the beam size suitable for the aluminum ball dump window.

WEPAC14

Studies of the Superconducting Traveling Wave Cavity for High Gradient Linac

820

P.V. Avrakhov, A. Kanareykin, R.A. Kostin
Euclid TechLabs, LLC, Solon, Ohio, USA
N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

Use of a traveling wave (TW) accelerating structure with a small phase advance per cell rather than a standing wave structure may provide a significant increase of the accelerating gradient in superconducting linacs. For the same surface electric and magnetic fields the TW achieves an accelerating gradient 1.2/1.4 larger than TESLA-like standing wave cavities [1]. Recent tests of L-band model of a single-cell cavity with waveguide feedback [2] demonstrated an accelerating gradient comparable to the gradient in a single-cell ILC-type cavity from the same manufacturer. This article presents the next stage of development of the TW resonance ring with 3-cell accelerating cavity which supposed to test in traveling wave regime. The main simulation results of the microphonics and Lorentz force detuning are also considered.

WEPAC22

Single Spoke Resonator Inner Electrode Optimization Driven by Reduction of Multipoles

835

P. Berrutti, T.N. Khabiboulline, L. Ristori, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

Accelerating cavities based on coaxial resonators, half wave and spoke resonators for example, do not have azimuthal symmetry. This lack of symmetry introduces a transverse field perturbation which affects the beam dynamic, since the particles traveling through the structure are crossing two accelerating gaps separated by the inner electrode. The field asymmetry induces an asymmetric transverse momentum gain which, once expanded in multipoles, appears to be due to a quadrupole perturbation. Depending on the cavity geometry and particle velocity, the influence of electric and magnetic fields may vary quite significantly. A way of having symmetric transverse fields in spoke resonators consists in modifying the inner electrode from a pole to an X or Y shape. The application of these changes symmetrizes both electric and magnetic fields and reduces the multipoles amplitudes to negligible values. This paper presents the study aimed to reduce the multi-poles amplitudes of SSR2 cavity for Project X; the presented procedure, in general, is valid for any spoke cavity.

WEPHO19

High-Power Low-Voltage Multi-Beam Klystrons for ILC and Project-X

978

S.V. Shchelkunov
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
J.L. Hirshfield
Yale University, Physics Department, New Haven, CT, USA
J.L. Hirshfield
Omega-P, Inc., New Haven, USA
S. Kazakov, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA
V.E. Teryaev
BINP SB RAS, Novosibirsk, Russia

Funding: This research is supported by U.S. DoE
Two conceptual designs of multi-beam klystrons with parameters suitable for ILC and for the 8-GeV pulsed stage of Project X (PX) have been developed. The chief distinction of these tubes from other MBKs is their low operating voltage, namely 60 kV for the ILC tube and 30 kV for the PX tube. Advantages of low voltage include no requirement for pulse transformers or oil-tanks for high-voltage components, and compact modulators. A 6-beamlet quadrant of the ILC tube has been built and is undergoing tests; it is designed to produce 2.5 MW at 1.3 GHz in a 1.6 ms wide pulse at a 10 Hz pulse rate; a four-quadrant future version would produce 10 MW. The 6-beamlet PX tube is to produce 520kW, and would operate in one of two regimes, either at a repetition rate of 2Hz delivering 30 msec pulses, or at a repetition rate of 10Hz delivering 8.5 msec-long pulses. The PX tube is currently undergoing engineering design, with construction scheduled for completion towards the end of 2014.

Paper	Title	Page
MOPMA09	Status and Opportunities at Project X: A Multi-MW Facility for Intensity Frontier Research	315
	S.D. Holmes, M. Kaducak, R.D. Kephart, I. Kourbanis, V.A. Lebedev, C.S. Mishra, S. Nagaitsev, N. Solyak, R.S. Tschirhart Fermilab, Batavia, USA
	Funding: Work supported by the Fermi Research Alliance under U.S. Department of Energy contract number DE-AC02-07CH11359 Project X is a high intensity proton facility that will support a world-leading U.S. program in Intensity Frontier physics over the next several decades. Project X is currently under development by Fermilab in collaboration with national and international partners. Project X will be unique in its ability to deliver, simultaneously, up to 6 MW of site-wide beam power to multiple experiments, at energies ranging from 235 MeV to 120 GeV, and with flexible and independently controlled beam time patterns. Project X will support a wide range of experiments utilizing neutrino, muon, kaon, nucleon, and atomic probes [1,2]. In addition, Project X will lay the foundation for the long-term development of a Neutrino Factory and/or Muon Collider.

MOPMA10	Studies of Fault Scenarios in SC CW Project-X Linac	318
	A. Saini, J.-F. Ostiguy, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	The success of Project-X accelerator facility crucially depends on reliable operation of 1 GeV superconducting (SC) continuous wave (CW) linac at first stage. Operation at high intensity in CW mode puts stringent tolerances on beamline elements. Any fault scenario that affects nominal operation of beamline elements results in beam mismatch with subsequent sections. This in turn leads to emittance growth, and ultimately triggers beam losses. In worst case, it could affect the reliability of the machine and long downtime may be needed to replace the faulty elements. In order to reduce beam interruptions, a robust lattice design is required which can allow local retuning to make the machine operable in such scenarios. This paper presents studies performed to understand the consequences of failure of various beamline elements and discusses outcome of local retuning for different fault scenarios at critical locations in linac.

MOPMA12	Design Issues of High Intensity SC CW Ion Linac for Project-X facility	321
	A. Saini, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	Project-X is a high intensity proton facility which is primarily based on superconducting (SC) continuous wave (CW) linac. One of the most challenging tasks of Project-X facility is to have robust design of SC CW linac which can provide high quality beam to several experiments and subsequent pulsed linac simultaneously. Among the various technical problems associated with the SC CW linac, halo formation, beam mismatch, uncontrolled emittance growth and beam losses are the most crucial as they can limit overall performance and reliability. Scope of this paper is to address these issues for reference design of Project-X SC CW linac.

MOPMA13	Layout of Project-X Facility: A Reference Design	324
	A. Saini, J.-P. Carneiro, D.E. Johnson, J.-F. Ostiguy, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	Project-X is a proposed high intensity proton facility to be built at Fermilab. It will be a multi-user facility which can support several experiments simultaneously. In the current scenario, Project-X facility would be built in three stages. Each stage is associated with compelling scientific programs and in synergy with Fermilab infrastructure. This paper will present reference design of Project-X accelerator facility and discuss main motivations and requirements resulting in this layout and beam optics.

TUYAA1	The Project-X Injector Experiment: A Novel High Performance Front-end for a Future High Power Proton Facility at Fermilab	374
	S. Nagaitsev, S.D. Holmes, D.E. Johnson, M. Kaducak, R.D. Kephart, V.A. Lebedev, C.S. Mishra, A.V. Shemyakin, N. Solyak, R.P. Stanek, V.P. Yakovlev Fermilab, Batavia, USA D. Li LBNL, Berkeley, California, USA S. Malhotra, M.M. Pande, P. Singh BARC, Mumbai, India P.N. Ostroumov ANL, Argonne, USA
	This presentation should describe the Project X Injector Experiment (PXIE)and its connection with Project X. It should focus on the novel aspects of PXIE, namely the programmable, bunch-by-bunch chopping of a CW H⁻ beam; acceleration in CW superconducting RF structures immediately following the RFQ; operation of SRF structures adjacent to a high-power chopper target; and preservation of high-quality chopped beams with acceptable emittance growth and halo.
	Slides TUYAA1 [8.806 MB]

TUODB2	Longitudinal Beam Dynamics and LLRF Requirements for the Project X Pulsed Linac	439
	A. Vivoli, G.I. Cancelo, B. Chase, N. Solyak, P. Varghese Fermilab, Batavia, USA
	Project X is a high intensity proton facility being developed to support the intensity frontier physics program over the next two decades at Fermilab. The Reference Design is based on a continuous wave (CW) superconducting 3 GeV linac providing up to 1 and 3 MW of beam power at 1 and 3 GeV respectively, while a superconducting pulsed linac provides acceleration of roughly 4.3% of the beam delivered from the CW linac to the 8 GeV injection energy of the existing Recycler/Main Injector complex. In this paper we present the results of simulation of longitudinal beam dynamics and Low Level RF (LLRF) control system in the pulsed linac, operated for long pulses in presence of errors and cavity detuning for different RF configurations and settings, and set the requirements for the LLRF necessary to fulfill the specifications of the design.
	Slides TUODB2 [8.618 MB]

TUPBA12	Design of the ILC RTML Extraction Lines for the Renovated Two-stage Bunch Compressor	550
	S. Seletskiy BNL, Upton, Long Island, New York, USA N. Solyak Fermilab, Batavia, USA
	The renovated two-stage bunch compressor (BC) in the International Linear Collider Damping Ring to the Main Linac beamline requires new design for the extraction lines (EL). The ELs located downstream of each stage of the BC will be used for both an emergency abort dumping of the beam and the tune-up continuous train-by-train extraction. They must accept both compressed and uncompressed beam with energy spread of 1.4% and 0.1% respectively. In this paper we report the design that allowed minimizing the length of such extraction lines while offsetting the beam dumps from the main line by 5m distance required for acceptable radiation level in the service tunnel. Proposed extraction lines can accommodate beams with different energy spreads at the same time providing the beam size suitable for the aluminum ball dump window.

WEPAC14	Studies of the Superconducting Traveling Wave Cavity for High Gradient Linac	820
	P.V. Avrakhov, A. Kanareykin, R.A. Kostin Euclid TechLabs, LLC, Solon, Ohio, USA N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	Use of a traveling wave (TW) accelerating structure with a small phase advance per cell rather than a standing wave structure may provide a significant increase of the accelerating gradient in superconducting linacs. For the same surface electric and magnetic fields the TW achieves an accelerating gradient 1.2/1.4 larger than TESLA-like standing wave cavities [1]. Recent tests of L-band model of a single-cell cavity with waveguide feedback [2] demonstrated an accelerating gradient comparable to the gradient in a single-cell ILC-type cavity from the same manufacturer. This article presents the next stage of development of the TW resonance ring with 3-cell accelerating cavity which supposed to test in traveling wave regime. The main simulation results of the microphonics and Lorentz force detuning are also considered.

WEPAC22	Single Spoke Resonator Inner Electrode Optimization Driven by Reduction of Multipoles	835
	P. Berrutti, T.N. Khabiboulline, L. Ristori, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	Accelerating cavities based on coaxial resonators, half wave and spoke resonators for example, do not have azimuthal symmetry. This lack of symmetry introduces a transverse field perturbation which affects the beam dynamic, since the particles traveling through the structure are crossing two accelerating gaps separated by the inner electrode. The field asymmetry induces an asymmetric transverse momentum gain which, once expanded in multipoles, appears to be due to a quadrupole perturbation. Depending on the cavity geometry and particle velocity, the influence of electric and magnetic fields may vary quite significantly. A way of having symmetric transverse fields in spoke resonators consists in modifying the inner electrode from a pole to an X or Y shape. The application of these changes symmetrizes both electric and magnetic fields and reduces the multipoles amplitudes to negligible values. This paper presents the study aimed to reduce the multi-poles amplitudes of SSR2 cavity for Project X; the presented procedure, in general, is valid for any spoke cavity.

WEPHO19	High-Power Low-Voltage Multi-Beam Klystrons for ILC and Project-X	978
	S.V. Shchelkunov Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA J.L. Hirshfield Yale University, Physics Department, New Haven, CT, USA J.L. Hirshfield Omega-P, Inc., New Haven, USA S. Kazakov, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA V.E. Teryaev BINP SB RAS, Novosibirsk, Russia
	Funding: This research is supported by U.S. DoE Two conceptual designs of multi-beam klystrons with parameters suitable for ILC and for the 8-GeV pulsed stage of Project X (PX) have been developed. The chief distinction of these tubes from other MBKs is their low operating voltage, namely 60 kV for the ILC tube and 30 kV for the PX tube. Advantages of low voltage include no requirement for pulse transformers or oil-tanks for high-voltage components, and compact modulators. A 6-beamlet quadrant of the ILC tube has been built and is undergoing tests; it is designed to produce 2.5 MW at 1.3 GHz in a 1.6 ms wide pulse at a 10 Hz pulse rate; a four-quadrant future version would produce 10 MW. The 6-beamlet PX tube is to produce 520kW, and would operate in one of two regimes, either at a repetition rate of 2Hz delivering 30 msec pulses, or at a repetition rate of 10Hz delivering 8.5 msec-long pulses. The PX tube is currently undergoing engineering design, with construction scheduled for completion towards the end of 2014.