PAC2013 - List of Authors (Yakovlev, V.P.)

Paper

Title

Page

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]

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.

WEPAC21

Tuning Process of SSR1 Cavity for Project X at FNAL

832

P. Berrutti, M.H. Awida, T.N. Khabiboulline, D. Passarelli, L. Ristori, V.P. Yakovlev
Fermilab, Batavia, USA

SSR1 is a family of single spoke resonators to be used in Project X at Fermi National Laboratory. These cavities operate in CW regime having nominal frequency of 325 MHz and optimal beta of 0.22. SSR1 cavities will accelerate H⁻ ions after the Half Wave Resonator (HWR) section from 9 MeV to 32 MeV. In the near future this cavity will be used in Project X Injector Experiment (PXIE), which contains the ion source, the LEBT, the MEBT, the RFQ of Project X, and a cryogenic temperature section, having one HWR and one SSR1 cryomodule. SSR1 cavities have been built and tested at FNAL, the preparation of these resonators includes RF tuning which is the main focus of this paper. The frequency of the cavity is carefully chosen prior to the vertical test, and it is adjusted before welding the helium vessel to obtain 325 MHz nominal frequency for the dressed cavity in operating conditions. Several SSR1 cavities have been tuned at FNAL, the procedure, the hardware and the data are presented.

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.

WEPAC23

Multipacting Simulations of SSR2 Cavity at FNAL

838

P. Berrutti, T.N. Khabiboulline, L. Ristori, G.V. Romanov, A.I. Sukhanov, V.P. Yakovlev
Fermilab, Batavia, USA

SSR2 is the second family of single spoke resonator under development at Fermi National Accelerator Laboratory (FNAL). These cavities will be placed in Project X front-end after SSR1 spoke resonators, which have already been built and tested and FNAL. Spoke cavities are affected by multipacting and the nature of their 3D geometry does not allow simulating the multipactor process using 2D tools. 3D tracking simulations, of electrons inside the cavity volume, have been carried out using CST Particle Studio. Different Secondary Emission Coefficients have been applied to the cavity walls in order to understand how strongly the multipacting depends on material properties. The power levels used in simulations cover the whole operating gradient range of SSR2 cavity. Results of these simulations are compared to the one given by SSR1 model, which demonstrated good agreement with experimental data. The purposes of this paper are to present the results gotten from the tracking solver, to give a prediction of what will be the multipacting scenario for SSR2 cavity and if there will be any dangerous zone for operation.

WEPAC25

New Helium Vessel and Lever Tuner Designs for the 650 MHz Cavities for Project X

841

I.V. Gonin, M.H. Awida, E. Borissov, M.H. Foley, C.J. Grimm, T.N. Khabiboulline, M. Merio, Y.M. Pischalnikov, L. Ristori, V.P. Yakovlev
Fermilab, Batavia, USA

The design of 5-cell elliptical 650 MHz β=0.9 cavities to accelerate H⁻ beam of 1 mA average current in the range 467-3000 MeV for the Project X Linac is currently under development at Fermilab. A new design of the Helium Vessel (HV) was developed for these cavities with the main goal of optimizing the frequency sensitivity df/dP by keeping the cavity stiffness reasonably small. We also present a design of the new lever tuner system. The HV in the new design is equipped with the tuner located at the end of the cavity instead of the initially proposed blade tuner located in the middle. We will present mechanical design results and ANSYS analyses for both the slow and fast tuners.

WEPAC29

CM2, Second 1.3GHz Cryomodule Fabrication at Fermilab

844

T.T. Arkan, M.H. Awida, P. Berrutti, E. Borissov, C.M. Ginsburg, C.J. Grimm, E.R. Harms, A. Hocker, T.N. Khabiboulline, Y.O. Orlov, T.J. Peterson, R.V. Pilipenko, Y.M. Pischalnikov, K.S. Premo, L. Ristori, W. Schappert, V.P. Yakovlev
Fermilab, Batavia, USA

Funding: US Department of Energy
CM2 is the second 1.3GHz Cryomodule assembled at the Cryomodule Assembly Facility (CAF) in Fermi National Accelerator Laboratory. The string has a doublet magnet, beam position monitor and eight cavities. All the cavities are qualified at 35 MV / m gradient at the Horizontal Test Facility before assembly. The dressed cavities were outfitted with magnetic shielding, blade tuner, and the cold mass was assembled based on the Tesla TTF Type III+ cryomodule design. CM2 is currently being installed into the test stand in NML where it will be cooled down and high power tested. CM2 will also be the first cryomodule that an electron beam will be put through at the NML facility. This will be a proof of principle for the planned Advanced Superconducting Test Accelerator (ASTA) facility at NML. This paper describes the assembly steps, the quality assurance methods and the challenges that we experienced during assembly and qualification steps at CAF. De

WEPAC32

Wakefield Loss Analysis of the Elliptical 3.9 GHz Third Harmonic Cavity

847

M.H. Awida, P. Berrutti, T.N. Khabiboulline, A. Saini, V.P. Yakovlev
Fermilab, Batavia, USA

Third harmonic 3.9 GHz elliptical cavities are planned to be used in many particle accelerator projects such as XFEL, NGLS, and ASTA. In this paper, the wakefield losses due to single bunch passage are analysed considering bunches of RMS length 8 mm down to ultra short ones of 10 μm length. Both the loss and kick factors are numerically calculated for bunches of relatively long length (>1 mm) using CST wakefield solver. The data is then used to extrapolate asymptotically the values for ultra-short bunches by finding the wake functions. These calculations are essential to estimate the cryogenic losses in cryomodules and for beam dynamic analysis.

WEPHO15

Modeling of Magnetron Transmitter for the Project X CW 1 GEV Linac

966

G.M. Kazakevich, R.P. Johnson
Muons, Inc, Illinois, USA
B. Chase, R.J. Pasquinelli, V.P. Yakovlev
Fermilab, Batavia, USA

A 650 MHz 50 kW transmitter with a wide-band control in phase and power, based on injection-locked CW magnetrons, intended to drive individually Superconducting RF (SRF) cavities has been proposed for the Project X CW 1 GeV linac. Utilization of the magnetron RF sources for the intensity-frontier project will save a significant capital cost in comparison with traditional RF sources based on klystrons, Inductive Output Tubes (IOTs), solid-state amplifiers. The transmitter setup has been modelled experimentally and by simulation using 2.45 GHz CW magnetrons with output power up to 1 kW. The measurements and simulations performed with the injection-locked magnetrons demonstrated capability of the proposed transmitter concept to power individually the superconducting cavities suppressing parasitic modulation of the accelerating field caused by mechanical oscillation (microphonics and oscillations resulted from Lorentz-force), beam loading, dynamic tuning errors, and other low-frequency disturbances of the magnetron performance. Results of the experimental and theoretical modelling are analysed and discussed in this paper.

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
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]

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.

WEPAC21	Tuning Process of SSR1 Cavity for Project X at FNAL	832
	P. Berrutti, M.H. Awida, T.N. Khabiboulline, D. Passarelli, L. Ristori, V.P. Yakovlev Fermilab, Batavia, USA
	SSR1 is a family of single spoke resonators to be used in Project X at Fermi National Laboratory. These cavities operate in CW regime having nominal frequency of 325 MHz and optimal beta of 0.22. SSR1 cavities will accelerate H⁻ ions after the Half Wave Resonator (HWR) section from 9 MeV to 32 MeV. In the near future this cavity will be used in Project X Injector Experiment (PXIE), which contains the ion source, the LEBT, the MEBT, the RFQ of Project X, and a cryogenic temperature section, having one HWR and one SSR1 cryomodule. SSR1 cavities have been built and tested at FNAL, the preparation of these resonators includes RF tuning which is the main focus of this paper. The frequency of the cavity is carefully chosen prior to the vertical test, and it is adjusted before welding the helium vessel to obtain 325 MHz nominal frequency for the dressed cavity in operating conditions. Several SSR1 cavities have been tuned at FNAL, the procedure, the hardware and the data are presented.

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.

WEPAC23	Multipacting Simulations of SSR2 Cavity at FNAL	838
	P. Berrutti, T.N. Khabiboulline, L. Ristori, G.V. Romanov, A.I. Sukhanov, V.P. Yakovlev Fermilab, Batavia, USA
	SSR2 is the second family of single spoke resonator under development at Fermi National Accelerator Laboratory (FNAL). These cavities will be placed in Project X front-end after SSR1 spoke resonators, which have already been built and tested and FNAL. Spoke cavities are affected by multipacting and the nature of their 3D geometry does not allow simulating the multipactor process using 2D tools. 3D tracking simulations, of electrons inside the cavity volume, have been carried out using CST Particle Studio. Different Secondary Emission Coefficients have been applied to the cavity walls in order to understand how strongly the multipacting depends on material properties. The power levels used in simulations cover the whole operating gradient range of SSR2 cavity. Results of these simulations are compared to the one given by SSR1 model, which demonstrated good agreement with experimental data. The purposes of this paper are to present the results gotten from the tracking solver, to give a prediction of what will be the multipacting scenario for SSR2 cavity and if there will be any dangerous zone for operation.

WEPAC25	New Helium Vessel and Lever Tuner Designs for the 650 MHz Cavities for Project X	841
	I.V. Gonin, M.H. Awida, E. Borissov, M.H. Foley, C.J. Grimm, T.N. Khabiboulline, M. Merio, Y.M. Pischalnikov, L. Ristori, V.P. Yakovlev Fermilab, Batavia, USA
	The design of 5-cell elliptical 650 MHz β=0.9 cavities to accelerate H⁻ beam of 1 mA average current in the range 467-3000 MeV for the Project X Linac is currently under development at Fermilab. A new design of the Helium Vessel (HV) was developed for these cavities with the main goal of optimizing the frequency sensitivity df/dP by keeping the cavity stiffness reasonably small. We also present a design of the new lever tuner system. The HV in the new design is equipped with the tuner located at the end of the cavity instead of the initially proposed blade tuner located in the middle. We will present mechanical design results and ANSYS analyses for both the slow and fast tuners.

WEPAC29	CM2, Second 1.3GHz Cryomodule Fabrication at Fermilab	844
	T.T. Arkan, M.H. Awida, P. Berrutti, E. Borissov, C.M. Ginsburg, C.J. Grimm, E.R. Harms, A. Hocker, T.N. Khabiboulline, Y.O. Orlov, T.J. Peterson, R.V. Pilipenko, Y.M. Pischalnikov, K.S. Premo, L. Ristori, W. Schappert, V.P. Yakovlev Fermilab, Batavia, USA
	Funding: US Department of Energy CM2 is the second 1.3GHz Cryomodule assembled at the Cryomodule Assembly Facility (CAF) in Fermi National Accelerator Laboratory. The string has a doublet magnet, beam position monitor and eight cavities. All the cavities are qualified at 35 MV / m gradient at the Horizontal Test Facility before assembly. The dressed cavities were outfitted with magnetic shielding, blade tuner, and the cold mass was assembled based on the Tesla TTF Type III+ cryomodule design. CM2 is currently being installed into the test stand in NML where it will be cooled down and high power tested. CM2 will also be the first cryomodule that an electron beam will be put through at the NML facility. This will be a proof of principle for the planned Advanced Superconducting Test Accelerator (ASTA) facility at NML. This paper describes the assembly steps, the quality assurance methods and the challenges that we experienced during assembly and qualification steps at CAF. De

WEPAC32	Wakefield Loss Analysis of the Elliptical 3.9 GHz Third Harmonic Cavity	847
	M.H. Awida, P. Berrutti, T.N. Khabiboulline, A. Saini, V.P. Yakovlev Fermilab, Batavia, USA
	Third harmonic 3.9 GHz elliptical cavities are planned to be used in many particle accelerator projects such as XFEL, NGLS, and ASTA. In this paper, the wakefield losses due to single bunch passage are analysed considering bunches of RMS length 8 mm down to ultra short ones of 10 μm length. Both the loss and kick factors are numerically calculated for bunches of relatively long length (>1 mm) using CST wakefield solver. The data is then used to extrapolate asymptotically the values for ultra-short bunches by finding the wake functions. These calculations are essential to estimate the cryogenic losses in cryomodules and for beam dynamic analysis.

WEPHO15	Modeling of Magnetron Transmitter for the Project X CW 1 GEV Linac	966
	G.M. Kazakevich, R.P. Johnson Muons, Inc, Illinois, USA B. Chase, R.J. Pasquinelli, V.P. Yakovlev Fermilab, Batavia, USA
	A 650 MHz 50 kW transmitter with a wide-band control in phase and power, based on injection-locked CW magnetrons, intended to drive individually Superconducting RF (SRF) cavities has been proposed for the Project X CW 1 GeV linac. Utilization of the magnetron RF sources for the intensity-frontier project will save a significant capital cost in comparison with traditional RF sources based on klystrons, Inductive Output Tubes (IOTs), solid-state amplifiers. The transmitter setup has been modelled experimentally and by simulation using 2.45 GHz CW magnetrons with output power up to 1 kW. The measurements and simulations performed with the injection-locked magnetrons demonstrated capability of the proposed transmitter concept to power individually the superconducting cavities suppressing parasitic modulation of the accelerating field caused by mechanical oscillation (microphonics and oscillations resulted from Lorentz-force), beam loading, dynamic tuning errors, and other low-frequency disturbances of the magnetron performance. Results of the experimental and theoretical modelling are analysed and discussed in this paper.

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.