PAC2013 - List of Authors (Murokh, A.Y.)

Paper

Title

Page

Removal of Residual Chirp in Compressed Beams Using a Passive Wakefield Technique

291

M.A. Harrison, G. Andonian, T.J. Campese, P. Frigola, A.Y. Murokh, F.H. O'Shea, M. Ruelas
RadiaBeam, Santa Monica, USA
M.G. Fedurin
BNL, Upton, Long Island, New York, USA

Funding: This is experiment is supported by an ongoing DOE Phase I Small Business Initiative for Research (SBIR) Grant, number DE–-SC0009550.
The removal of residual chirp in XFELs is of paramount importance for efficient lasing. Although current S-band XFELs remove the unwanted residual chirp using off-crest acceleration after the final bunch compressor, this technique is not possible for XFELs with soft X-ray lines as there are no further accelerating structures. The off-crest dechirping technique is also expensive for future superconducting XFELs. In response, RadiaBeam Systems presents its work, building upon the theoretical work of Bane and Stupakov*, in RF-free residual chirp mitigation using only passive techniques. Beam-induced longitudinal wakefields are produced with opposing corrugated plates which allow for an entirely RF-free chirp removal. Theory, engineering, and experimental results are presented.
* K.L.F. Bane, G. Stupakov, Nucl. Inst. Meth. 690 (2012) 106-110

TUOAB2

Continued Development and Testing of Carbon Nanotube Cathodes at Radiabeam

394

J.J. Hartzell, R.B. Agustsson, S. Boucher, L. Faillace, A.Y. Murokh, A.V. Smirnov
RadiaBeam, Santa Monica, USA
W.A. Hubbard, C. Regan
UCLA, Los Angeles, USA

Funding: US Department of Energy
RadiaBeam Technologies is developing carbon nanotube (CNT) based field emission cathodes for DC-pulsed and radio-frequency electron sources. CNT cathodes offer simple operation, have demonstrated high current densities, and can maintain low thermal emittance due to their ability to emit at room temperature. The experimental results of high-voltage and lifetime testing of CNT cathodes are presented. There is also a brief summary of a planned experiment in a dual-frequency RF gun. Additionally, some of the challenges posed by the fabrication and handling of the CNT cathodes are discussed.

Slides TUOAB2 [10.433 MB]

WEPBA17

Measurement of Non-Linear Insert Magnets

922

F.H. O'Shea, R.B. Agustsson, A.Y. Murokh, E. Spranza
RadiaBeam, Marina del Rey, USA
S. Nagaitsev, A. Valishev
Fermilab, Batavia, USA

Fermilab's Integrable Optics Test Accelerator (IOTA) is an electron storage ring designed for testing advanced accelerator physics concepts, including implementation of nonlinear integrable beam optics and experiments on optical stochastic cooling. In this report we describe the contribution of RadiaBeam Technologies to the IOTA project which includes nonlinear magnet engineering, production and measurement.

THOAA2

Compact, Inexpensive X-band Linacs as Radioactive Isotope Source Replacements

S. Boucher, R.B. Agustsson, L. Faillace, J.J. Hartzell, A.Y. Murokh, S. Seung, A.V. Smirnov, S. Storms, K.E. Woods
RadiaBeam, Santa Monica, USA

Funding: Work supported by DNDO Phase II SBIR HSHQDC-10-C-00148 and DOE Phase II SBIR DE-SC0000865.
Radioisotope sources are commonly used in a variety of industrial and medical applications. The US National Research Council has identified as a priority the replacement of high-activity sources with alternative technologies, due to the risk of accidents and diversion by terrorists for use in Radiological Dispersal Devices (“dirty bombs”). RadiaBeam Technologies is developing novel, compact, inexpensive linear accelerators for use in a variety of such applications as cost-effective replacements. The technology is based on the MicroLinac (originally developed at SLAC), an X-band linear accelerator powered by an inexpensive and commonly available magnetron. Prototypes are currently under construction. This paper will describe the design, engineering, fabrication and testing of these linacs at RadiaBeam. Future development plans will also be discussed.

Slides THOAA2 [6.067 MB]

THPAC29

Fabrication and Validation of a Normal Conducting Radio Frequency S-Band Deflecting Cavity for the Pohang Accelerator Laboratory (PAL)

1202

L. Faillace, R.B. Agustsson, J.J. Hartzell, A.Y. Murokh, S. Storms
RadiaBeam, Santa Monica, USA

Radiabeam Technologies recently developed an S-Band normal-conducting radio-Frequency (NCRF) deflecting cavity for the Pohang Accelerator Laboratory (PAL) in order to perform longitudinal characterization of the sub-picosecond ultra-relativistic electron beams. The device is optimized for the 135 MeV electron beam parameters. The 1m-long PAL deflector is designed to operate at 2.856 GHz and features short filling time and femtosecond resolution. RF design, fabrication, RF validation and tuning will be presented, as well as initial beam measurements.

THPAC32

Transverse Beam Profile Diagnostic Using Fiber Optic Array

1205

S. Wu, R.B. Agustsson, G. Andonian, T.J. Campese, A.Y. Murokh
RadiaBeam, Santa Monica, USA
M.G. Fedurin, K. Kusche, R. Malone, C. Swinson
BNL, Upton, Long Island, New York, USA
R.K. Li
UCLA, Los Angeles, California, USA

Funding: This work is supported by U.S. D.O.E Contract Number DE-SC0000870
The fiber-mesh diagnostic (FMD) is a transverse beam profile diagnostic based on the emission and detection of Cherenkov radiation produced as a relativistic electron beam traverses through an ordered bundle of fiber optics (SiO2), arranged in a hexagonal close-pack configuration. Sub-10μm transverse beam profile resolution is attainable due to fiber optic core concentricity. Adequate SNR is achieved using a standard CCD sensor. A fiber optic taper input maximizes light collection efficiency by coupling each output channel to approximately single-pixel pitch. A v-groove holder and assembly process was developed to hold many fiber layers in the desired configuration. In this paper, we present results from a fully functional FMD prototype evaluated at the BNL ATF facility that demonstrates the efficacy of this diagnostic.

THPAC36

Progress in the Development of Textured Dysprosium for Undulator Applications

1217

F.H. O'Shea
UCLA, Los Angeles, California, USA
R.B. Agustsson, Y.C. Chen, T.J. Grandsaert, A.Y. Murokh, K.E. Woods
RadiaBeam, Santa Monica, USA
J. Park, R.L. Stillwell
NHMFL, Tallahassee, Florida, USA

RadiaBeam Technologies is in the process of developing bulk textured dysprosium as a potential replacement for CoFe steel as undulator poles. For cryogenic undulators that can be cooled below the ferromagnetic transition of dysprosium, textured dysprosium offers potential increase in the peak field of the undulator. Here we report on the progress of the project, including magnetization curves for the material and simulations of a short period undulator utilizing the material.

Paper	Title	Page
MOPHO25	Removal of Residual Chirp in Compressed Beams Using a Passive Wakefield Technique	291
	M.A. Harrison, G. Andonian, T.J. Campese, P. Frigola, A.Y. Murokh, F.H. O'Shea, M. Ruelas RadiaBeam, Santa Monica, USA M.G. Fedurin BNL, Upton, Long Island, New York, USA
	Funding: This is experiment is supported by an ongoing DOE Phase I Small Business Initiative for Research (SBIR) Grant, number DE–-SC0009550. The removal of residual chirp in XFELs is of paramount importance for efficient lasing. Although current S-band XFELs remove the unwanted residual chirp using off-crest acceleration after the final bunch compressor, this technique is not possible for XFELs with soft X-ray lines as there are no further accelerating structures. The off-crest dechirping technique is also expensive for future superconducting XFELs. In response, RadiaBeam Systems presents its work, building upon the theoretical work of Bane and Stupakov, in RF-free residual chirp mitigation using only passive techniques. Beam-induced longitudinal wakefields are produced with opposing corrugated plates which allow for an entirely RF-free chirp removal. Theory, engineering, and experimental results are presented. K.L.F. Bane, G. Stupakov, Nucl. Inst. Meth. 690 (2012) 106-110

TUOAB2	Continued Development and Testing of Carbon Nanotube Cathodes at Radiabeam	394
	J.J. Hartzell, R.B. Agustsson, S. Boucher, L. Faillace, A.Y. Murokh, A.V. Smirnov RadiaBeam, Santa Monica, USA W.A. Hubbard, C. Regan UCLA, Los Angeles, USA
	Funding: US Department of Energy RadiaBeam Technologies is developing carbon nanotube (CNT) based field emission cathodes for DC-pulsed and radio-frequency electron sources. CNT cathodes offer simple operation, have demonstrated high current densities, and can maintain low thermal emittance due to their ability to emit at room temperature. The experimental results of high-voltage and lifetime testing of CNT cathodes are presented. There is also a brief summary of a planned experiment in a dual-frequency RF gun. Additionally, some of the challenges posed by the fabrication and handling of the CNT cathodes are discussed.
	Slides TUOAB2 [10.433 MB]

WEPBA17	Measurement of Non-Linear Insert Magnets	922
	F.H. O'Shea, R.B. Agustsson, A.Y. Murokh, E. Spranza RadiaBeam, Marina del Rey, USA S. Nagaitsev, A. Valishev Fermilab, Batavia, USA
	Fermilab's Integrable Optics Test Accelerator (IOTA) is an electron storage ring designed for testing advanced accelerator physics concepts, including implementation of nonlinear integrable beam optics and experiments on optical stochastic cooling. In this report we describe the contribution of RadiaBeam Technologies to the IOTA project which includes nonlinear magnet engineering, production and measurement.

THOAA2	Compact, Inexpensive X-band Linacs as Radioactive Isotope Source Replacements
	S. Boucher, R.B. Agustsson, L. Faillace, J.J. Hartzell, A.Y. Murokh, S. Seung, A.V. Smirnov, S. Storms, K.E. Woods RadiaBeam, Santa Monica, USA
	Funding: Work supported by DNDO Phase II SBIR HSHQDC-10-C-00148 and DOE Phase II SBIR DE-SC0000865. Radioisotope sources are commonly used in a variety of industrial and medical applications. The US National Research Council has identified as a priority the replacement of high-activity sources with alternative technologies, due to the risk of accidents and diversion by terrorists for use in Radiological Dispersal Devices (“dirty bombs”). RadiaBeam Technologies is developing novel, compact, inexpensive linear accelerators for use in a variety of such applications as cost-effective replacements. The technology is based on the MicroLinac (originally developed at SLAC), an X-band linear accelerator powered by an inexpensive and commonly available magnetron. Prototypes are currently under construction. This paper will describe the design, engineering, fabrication and testing of these linacs at RadiaBeam. Future development plans will also be discussed.
	Slides THOAA2 [6.067 MB]

THPAC29	Fabrication and Validation of a Normal Conducting Radio Frequency S-Band Deflecting Cavity for the Pohang Accelerator Laboratory (PAL)	1202
	L. Faillace, R.B. Agustsson, J.J. Hartzell, A.Y. Murokh, S. Storms RadiaBeam, Santa Monica, USA
	Radiabeam Technologies recently developed an S-Band normal-conducting radio-Frequency (NCRF) deflecting cavity for the Pohang Accelerator Laboratory (PAL) in order to perform longitudinal characterization of the sub-picosecond ultra-relativistic electron beams. The device is optimized for the 135 MeV electron beam parameters. The 1m-long PAL deflector is designed to operate at 2.856 GHz and features short filling time and femtosecond resolution. RF design, fabrication, RF validation and tuning will be presented, as well as initial beam measurements.

THPAC32	Transverse Beam Profile Diagnostic Using Fiber Optic Array	1205
	S. Wu, R.B. Agustsson, G. Andonian, T.J. Campese, A.Y. Murokh RadiaBeam, Santa Monica, USA M.G. Fedurin, K. Kusche, R. Malone, C. Swinson BNL, Upton, Long Island, New York, USA R.K. Li UCLA, Los Angeles, California, USA
	Funding: This work is supported by U.S. D.O.E Contract Number DE-SC0000870 The fiber-mesh diagnostic (FMD) is a transverse beam profile diagnostic based on the emission and detection of Cherenkov radiation produced as a relativistic electron beam traverses through an ordered bundle of fiber optics (SiO2), arranged in a hexagonal close-pack configuration. Sub-10μm transverse beam profile resolution is attainable due to fiber optic core concentricity. Adequate SNR is achieved using a standard CCD sensor. A fiber optic taper input maximizes light collection efficiency by coupling each output channel to approximately single-pixel pitch. A v-groove holder and assembly process was developed to hold many fiber layers in the desired configuration. In this paper, we present results from a fully functional FMD prototype evaluated at the BNL ATF facility that demonstrates the efficacy of this diagnostic.

THPAC36	Progress in the Development of Textured Dysprosium for Undulator Applications	1217
	F.H. O'Shea UCLA, Los Angeles, California, USA R.B. Agustsson, Y.C. Chen, T.J. Grandsaert, A.Y. Murokh, K.E. Woods RadiaBeam, Santa Monica, USA J. Park, R.L. Stillwell NHMFL, Tallahassee, Florida, USA
	RadiaBeam Technologies is in the process of developing bulk textured dysprosium as a potential replacement for CoFe steel as undulator poles. For cryogenic undulators that can be cooled below the ferromagnetic transition of dysprosium, textured dysprosium offers potential increase in the peak field of the undulator. Here we report on the progress of the project, including magnetization curves for the material and simulations of a short period undulator utilizing the material.