IPAC2016 - List of Authors (Murokh, A.Y.)

Paper	Title	Page
MOPMY037	GaN Class-F Power Amplifier for Klystron Replacement	583
	A.V. Smirnov RadiaBeam Systems, Santa Monica, California, USA R.B. Agustsson, S. Boucher, D.I. Gavryushkin, J.J. Hartzell, K.J. Hoyt, A.Y. Murokh, T.J. Villabona RadiaBeam, Santa Monica, California, USA
	Funding: This work was supported by the U.S. Department of Energy (award No. DE-SC0013136) The vacuum-tube-based RF amplifiers are relatively inefficient and becoming obsolete as the RF world has been progressively converting to solid state technology. Currently, the JLAB upgrade program requires 340 amplifiers capable of 8 kW CW at 1497 MHz while operating at more than 55-60% efficiency to replace their klystrons. Here we explore the possibility of a klystron replacement employing high electron mobility packaged GaN transistors applied in an array of Class-F amplifiers. The inputs and outputs of the many modules needed to make a complete amplifier are connected via precise, in-phase, low-loss, broadband, combiners-dividers. We describe early prototypes of the amplifiers as well as the combiners-dividers and discuss the design features and challenges of such a scheme. This approach can be applied to other national facilities and also for replacement of the klystrons in Middle Energy Electron-Ion Collider which requires about 1.8 MW CW power in total to be produced at 952.6 MHz frequency including 2x12.5 kW power for "crabbing" and 0.53 MW for electron cooling.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY037
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOW054	Characterization of a Sub-THz Radiation Source Based on a 3 MeV Electron Beam and Future Plans	1892
	A.V. Smirnov, R.B. Agustsson, T.J. Campese, Y.C. Chen, J.J. Hartzell, B.T. Jacobson, A.Y. Murokh, M. Ruelas RadiaBeam, Santa Monica, California, USA W. Berg, J.C. Dooling, L. Erwin, R.R. Lindberg, S.J. Pasky, N. Sereno, Y.-E. Sun, A. Zholents ANL, Argonne, Ilinois, USA Y. Kim KAERI, Jeongeup-si, Republic of Korea
	Funding: This work was supported by the U.S. Department of Energy (award No. DE-SC-FOA-0007702) Design features and some past experimental results are presented for a sub-THz wave source employing the Advanced Photon Source's RF thermionic electron gun. The setup includes a compact alpha-magnet, four quadrupoles, a novel radiator, a THz transport line, and THz diagnostics. The radiator is composed of a dielectric-free, planar, over-sized structure with gratings. The gratings are integrated into a combined horn antenna and ~90° permanent bending magnet. The magnetic lattice enables operation in different modes, including conversion to a flat beam for efficient interaction with the radiating structure. The experiment described demonstrated the generation of narrow bandwidth THz radiation from a compact, laser and undulator-free, table-top system. This concept could be scaled to create a THz-sub-THz source capable of operating in long-pulse, multi-bunch, and CW modes. Additionally, the system can be used to remove unwanted time-dependent energy variations in longitudinally compressed electron bunches or for various time-dependent beam diagnostics. Plans for future experiments and upgrades are also discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW054
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOY041	A Metal-Dielectric Micro-Linac for Radiography Source Replacement	1992
	A.V. Smirnov, S. Boucher, S.V. Kutsaev RadiaBeam Systems, Santa Monica, California, USA R.B. Agustsson, R.D.B. Berry, J.J. Hartzell, J. McNevin, A.Y. Murokh RadiaBeam, Santa Monica, California, USA G. Leyh LOD, Brisbane, USA E.A. Savin MEPhI, Moscow, Russia
	Funding: * US Department of Energy Contract # DE-SC0011370 To improve public security and prevent the diversion of radioactive material for Radiation Dispersion Devices, RadiaBeam is developing an inexpensive, portable, easy-to-manufacture linac structure to allow effective capture of a ~13 keV electron beam injected from a conventional electron gun and acceleration to a final energy of ~ 1 MeV. The bremsstrahlung X-rays produced by the electron beam on a high-Z converter at the end of the linac will match the penetration and dose rate of a typical ~100 Ci or more Ir-192 source. The tubular Disk-and-Ring structure under development consists of metal and dielectric elements that reduce or even eliminate multi-cell, multi-step brazing. This may allow significant simplification of the fabrication process to enable inexpensive mass-production required for replacement of the ~55,000 radionuclide sources in the US
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY041
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMR056	Single-shot THz Spectrometer for Measurement of RF Breakdown in mm-wave Accelerators	374
	S.V. Kutsaev, A.Y. Murokh, M. Ruelas, E.A. Savin, H.L. To RadiaBeam Systems, Santa Monica, California, USA M. Dal Forno, V.A. Dolgashev SLAC, Menlo Park, California, USA V. Goncharik Logicware Inc, New York, USA E.A. Savin MEPhI, Moscow, Russia
	Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics, under contract DE-SC0013684 We present a new instrument designed to detect RF pulse shortening caused by vacuum RF breakdown in mm-wave particle accelerators. RF breakdown limits the performance of high gradient RF accelerators. To understand the properties of these breakdowns, it is necessary to have diagnostics that reliably detect RF breakdowns. In X-band or S-band accelerators, RF breakdowns are detected by measuring RF pulse shortening, vacuum burst, or, if current monitors are available, spikes in the field-emitted currents. In mm-wave accelerators, all of these methods are difficult to use. In our experiments, we could not measure RF pulse shortening directly with a crystal detector because the RF pulse is very short'just a few nanoseconds'and changes in the measured signal were masked by RF amplitude jitter. To overcome this limitation, we built a single-shot spectrometer with a frequency range of 117-125 GHz and a resolution of 0.1 GHz. The spectrometer should be able to measure the widening of the spectrum caused by the shortening of nanosecond-long pulses. We present design considerations, first experimental results obtained at FACET, and planned future improvements for the spectrometer.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR056
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOW049	Implementation of a Corrugated-Plate Dechirping System for GeV Electron Beam at LCLS	824
	M.A. Harrison, P. Frigola, J.D. McNevin, A.Y. Murokh, M. Ruelas RadiaBeam Systems, Santa Monica, California, USA A.M. Babbitt, M. Carrasco, A. Cedillos, R.H. Iverson, P. Krejcik, T.J. Maxwell, Ž. Oven SLAC, Menlo Park, California, USA
	Funding: This work is supported by US DOE Grant No. DE-SC0009550. A new corrugated-plate Dechirper was recently installed in the LCLS and underwent commissioning tests to gauge its efficacy in shaping the longitudinal phase space of bunches entering the FEL. Here, we describe in detail the completed four-meter LCLS Dechirper system along with a narrative of its construction. We detail the various challenges and lessons learned in the manufacturing and assembly of this first-of-its-kind device. An outlook on future designs is presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW049
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

GaN Class-F Power Amplifier for Klystron Replacement

583

A.V. Smirnov
RadiaBeam Systems, Santa Monica, California, USA
R.B. Agustsson, S. Boucher, D.I. Gavryushkin, J.J. Hartzell, K.J. Hoyt, A.Y. Murokh, T.J. Villabona
RadiaBeam, Santa Monica, California, USA

Funding: This work was supported by the U.S. Department of Energy (award No. DE-SC0013136)
The vacuum-tube-based RF amplifiers are relatively inefficient and becoming obsolete as the RF world has been progressively converting to solid state technology. Currently, the JLAB upgrade program requires 340 amplifiers capable of 8 kW CW at 1497 MHz while operating at more than 55-60% efficiency to replace their klystrons. Here we explore the possibility of a klystron replacement employing high electron mobility packaged GaN transistors applied in an array of Class-F amplifiers. The inputs and outputs of the many modules needed to make a complete amplifier are connected via precise, in-phase, low-loss, broadband, combiners-dividers. We describe early prototypes of the amplifiers as well as the combiners-dividers and discuss the design features and challenges of such a scheme. This approach can be applied to other national facilities and also for replacement of the klystrons in Middle Energy Electron-Ion Collider which requires about 1.8 MW CW power in total to be produced at 952.6 MHz frequency including 2x12.5 kW power for "crabbing" and 0.53 MW for electron cooling.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY037

Export •

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

TUPOW054

Characterization of a Sub-THz Radiation Source Based on a 3 MeV Electron Beam and Future Plans

1892

A.V. Smirnov, R.B. Agustsson, T.J. Campese, Y.C. Chen, J.J. Hartzell, B.T. Jacobson, A.Y. Murokh, M. Ruelas
RadiaBeam, Santa Monica, California, USA
W. Berg, J.C. Dooling, L. Erwin, R.R. Lindberg, S.J. Pasky, N. Sereno, Y.-E. Sun, A. Zholents
ANL, Argonne, Ilinois, USA
Y. Kim
KAERI, Jeongeup-si, Republic of Korea

Funding: This work was supported by the U.S. Department of Energy (award No. DE-SC-FOA-0007702)
Design features and some past experimental results are presented for a sub-THz wave source employing the Advanced Photon Source's RF thermionic electron gun. The setup includes a compact alpha-magnet, four quadrupoles, a novel radiator, a THz transport line, and THz diagnostics. The radiator is composed of a dielectric-free, planar, over-sized structure with gratings. The gratings are integrated into a combined horn antenna and ~90° permanent bending magnet. The magnetic lattice enables operation in different modes, including conversion to a flat beam for efficient interaction with the radiating structure. The experiment described demonstrated the generation of narrow bandwidth THz radiation from a compact, laser and undulator-free, table-top system. This concept could be scaled to create a THz-sub-THz source capable of operating in long-pulse, multi-bunch, and CW modes. Additionally, the system can be used to remove unwanted time-dependent energy variations in longitudinally compressed electron bunches or for various time-dependent beam diagnostics. Plans for future experiments and upgrades are also discussed.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW054

Export •

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

TUPOY041

A Metal-Dielectric Micro-Linac for Radiography Source Replacement

1992

A.V. Smirnov, S. Boucher, S.V. Kutsaev
RadiaBeam Systems, Santa Monica, California, USA
R.B. Agustsson, R.D.B. Berry, J.J. Hartzell, J. McNevin, A.Y. Murokh
RadiaBeam, Santa Monica, California, USA
G. Leyh
LOD, Brisbane, USA
E.A. Savin
MEPhI, Moscow, Russia

Funding: * US Department of Energy Contract # DE-SC0011370
To improve public security and prevent the diversion of radioactive material for Radiation Dispersion Devices, RadiaBeam is developing an inexpensive, portable, easy-to-manufacture linac structure to allow effective capture of a ~13 keV electron beam injected from a conventional electron gun and acceleration to a final energy of ~ 1 MeV. The bremsstrahlung X-rays produced by the electron beam on a high-Z converter at the end of the linac will match the penetration and dose rate of a typical ~100 Ci or more Ir-192 source. The tubular Disk-and-Ring structure under development consists of metal and dielectric elements that reduce or even eliminate multi-cell, multi-step brazing. This may allow significant simplification of the fabrication process to enable inexpensive mass-production required for replacement of the ~55,000 radionuclide sources in the US

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY041

Export •

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

MOPMR056

Single-shot THz Spectrometer for Measurement of RF Breakdown in mm-wave Accelerators

374

S.V. Kutsaev, A.Y. Murokh, M. Ruelas, E.A. Savin, H.L. To
RadiaBeam Systems, Santa Monica, California, USA
M. Dal Forno, V.A. Dolgashev
SLAC, Menlo Park, California, USA
V. Goncharik
Logicware Inc, New York, USA
E.A. Savin
MEPhI, Moscow, Russia

Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics, under contract DE-SC0013684
We present a new instrument designed to detect RF pulse shortening caused by vacuum RF breakdown in mm-wave particle accelerators. RF breakdown limits the performance of high gradient RF accelerators. To understand the properties of these breakdowns, it is necessary to have diagnostics that reliably detect RF breakdowns. In X-band or S-band accelerators, RF breakdowns are detected by measuring RF pulse shortening, vacuum burst, or, if current monitors are available, spikes in the field-emitted currents. In mm-wave accelerators, all of these methods are difficult to use. In our experiments, we could not measure RF pulse shortening directly with a crystal detector because the RF pulse is very short'just a few nanoseconds'and changes in the measured signal were masked by RF amplitude jitter. To overcome this limitation, we built a single-shot spectrometer with a frequency range of 117-125 GHz and a resolution of 0.1 GHz. The spectrometer should be able to measure the widening of the spectrum caused by the shortening of nanosecond-long pulses. We present design considerations, first experimental results obtained at FACET, and planned future improvements for the spectrometer.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR056

Export •

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

MOPOW049

Implementation of a Corrugated-Plate Dechirping System for GeV Electron Beam at LCLS

824

M.A. Harrison, P. Frigola, J.D. McNevin, A.Y. Murokh, M. Ruelas
RadiaBeam Systems, Santa Monica, California, USA
A.M. Babbitt, M. Carrasco, A. Cedillos, R.H. Iverson, P. Krejcik, T.J. Maxwell, Ž. Oven
SLAC, Menlo Park, California, USA

Funding: This work is supported by US DOE Grant No. DE-SC0009550.
A new corrugated-plate Dechirper was recently installed in the LCLS and underwent commissioning tests to gauge its efficacy in shaping the longitudinal phase space of bunches entering the FEL. Here, we describe in detail the completed four-meter LCLS Dechirper system along with a narrative of its construction. We detail the various challenges and lessons learned in the manufacturing and assembly of this first-of-its-kind device. An outlook on future designs is presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW049

Export •

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