NAPAC2016 - List of Authors (Nassiri, A.)

Paper	Title	Page
MOA4CO04	Compact Carbon Ion Linac	61
	P.N. Ostroumov, A. Goel, B. Mustapha, A. Nassiri, A.S. Plastun ANL, Argonne, Illinois, USA L. Faillace, S.V. Kutsaev, E.A. Savin RadiaBeam, Santa Monica, California, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics, under Accelerator Stewardship Grant, Proposal No. 0000219678. Argonne National Laboratory is developing an Advanced Compact Carbon Ion Linac (ACCIL) in collaboration with RadiaBeam Technologies. The 45-meter long linac is designed to deliver up to 10⁹ carbon ions per second with variable energy from 45 MeV/u to 450 MeV/u. To optimize the linac design in this energy range both backward traveling wave and coupled cell standing wave S-band structures were analyzed. To achieve the required accelerating gradients our design uses accelerating structures excited with short RF pulses (~500 ns flattop). The front-end accelerating structures such as the RFQ, DTL and Coupled Cell DTL are designed to operate at lower frequencies to maintain high shunt impedance. In parallel with our design effort ANL's RF test facility has been upgraded and used for the testing of an S-band high-gradient structure designed and built by Radiabeam for high pulsed RF power operation. The 5-cell S-band structure demonstrated 52 MV/m acceleration field at 2 μs 30 Hz RF pulses. A detailed physics design, including a comparison of different accelerating structures and end-to-end beam dynamics simulations of the ACCIL will be presented.
	Slides MOA4CO04 [3.531 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOA4CO04
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TUPOA14	An Internet Rack Monitor-Controller for APS LINAC RF Electronics Upgrade	314
	H. Ma, A. Nassiri, T.L. Smith, Y. Sun ANL, Argonne, Illinois, USA L.R. Doolittle, A. Ratti LBNL, Berkeley, California, USA
	Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences To support the current research and development in APS LINAC area, the existing LINAC rf control performance needs to be much improved, and thus an upgrade of the legacy LINAC rf electronics becomes necessary. The proposed upgrade plan centers on the concept of using a modern, network-attached, rack-mount digital electronics platform 'Internet Rack Monitor-Controller (or IRMC) to replace the existing analog ones on the legacy crate/backplane-based hardware. The system model of the envisioned IRMC is basically a 3-tier stack with a high-performance processor in the mid- layer to handle the general digital signal processing (DSP). The custom FPGA IP's in the bottom layer handle the high-speed, real-time, low-latency DSP tasks, and provide the interface ports. A network communication gateway, in conjunction with an embedded event receiver (EVR), in the top layer merges the Internet Rack Monitor-Controller device into the networks of the accelerator controls infrastructure. Although the concept is very much in trend with today's Internet-of-Things (IoT), this implementation has actually been used in accelerators for over two decades.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA14
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TUB3CO04	A New Thermionic RF Electron Gun for Synchrotron Light Sources	453
	S.V. Kutsaev, A.Y. Murokh, E.A. Savin, A.Yu. Smirnov, A.V. Smirnov RadiaBeam Systems, Santa Monica, California, USA R.B. Agustsson, J.J. Hartzell, A. Verma RadiaBeam, Santa Monica, California, USA A. Nassiri, Y. Sun, G.J. Waldschmidt, A. Zholents ANL, Argonne, Illinois, USA E.A. Savin MEPhI, Moscow, Russia
	Funding: This work is supported by the U.S. Department of Energy, Office of Basic Energy Science, under contract DE-SC0015191 and contract No. DE-AC02-06CH11357. A thermionic RF gun is a compact and efficient source of electrons used in many practical applications. RadiaBeam Systems and the Advanced Photon Source of Argonne National Laboratory collaborate in developing of a reliable and robust thermionic RF gun for synchrotron light sources which would offer substantial improvements over existing thermionic RF guns and allow stable operation with up to 1A of beam peak current at a 100 Hz pulse repetition rate and a 1.5 μs RF pulse length. In this paper, we discuss the electromagnetic and engineering design of the cavity, and report the progress towards high power tests of the cathode assembly of the new gun.
	Slides TUB3CO04 [2.661 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUB3CO04
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WEPOA13	RF Design and Simulation of a Non-Periodic Lattice Photonic Band Gap (PBG) Accelerating Structure	716
	N. Zhou, A. Nassiri ANL, Argonne, Illinois, USA
	Photonic Band Gap (PBG) structures (metallic and or dielectric) have been proposed for accelerators. These structures act like a filter, allowing RF field at some frequencies to be transmitted through, while rejecting RF fields in some (unwanted) frequency range. Additionally PBG structures are used to support selective field patterns (modes) in a resonator or waveguide. In this paper, we will report on the RF design and simulation results of an X-band PBG structure, including lattice optimization, to improve RF performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA13
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WEPOB07	Dielectrically-Loaded Waveguide as a Short Period Superconducting Microwave Undulator	897
	R. Kustom, A. Nassiri, K.J. Suthar, G.J. Waldschmidt ANL, Argonne, Illinois, USA
	The HEM12 mode in a cylindrical, dielectrically-loaded waveguide provides E and H fields on the central axis that are significantly higher than the fields on the conducting walls. The waveguide is designed to operate near its cutoff frequency where the wavelength and phase velocity vary significantly to enable tuning of the equivalent undulator wavelength. The operating frequency would range from 18 - 24 GHz. It would be possible to generate coherent, high-energy 45 - 65 KeV x-rays from the fundamental mode which are tunable over a 20% energy range by changing the source frequency while maintaining constant field strengths. The x-ray brilliance of the microwave undulator would be 3 times higher at 56-KeV and 7 times higher at 66 KeV than what is available with the APS 1.8 cm period Superconducting Wire Undulator. Since the loss factor of sapphire is very low at cryogenic temperatures, it is possible to consider a superconducting microwave undulator, although resistive losses of ~200 to 700 W/m may be a bit too high for CW operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB07
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Paper

Title

Page

Compact Carbon Ion Linac

61

P.N. Ostroumov, A. Goel, B. Mustapha, A. Nassiri, A.S. Plastun
ANL, Argonne, Illinois, USA
L. Faillace, S.V. Kutsaev, E.A. Savin
RadiaBeam, Santa Monica, California, USA

Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics, under Accelerator Stewardship Grant, Proposal No. 0000219678.
Argonne National Laboratory is developing an Advanced Compact Carbon Ion Linac (ACCIL) in collaboration with RadiaBeam Technologies. The 45-meter long linac is designed to deliver up to 10⁹ carbon ions per second with variable energy from 45 MeV/u to 450 MeV/u. To optimize the linac design in this energy range both backward traveling wave and coupled cell standing wave S-band structures were analyzed. To achieve the required accelerating gradients our design uses accelerating structures excited with short RF pulses (~500 ns flattop). The front-end accelerating structures such as the RFQ, DTL and Coupled Cell DTL are designed to operate at lower frequencies to maintain high shunt impedance. In parallel with our design effort ANL's RF test facility has been upgraded and used for the testing of an S-band high-gradient structure designed and built by Radiabeam for high pulsed RF power operation. The 5-cell S-band structure demonstrated 52 MV/m acceleration field at 2 μs 30 Hz RF pulses. A detailed physics design, including a comparison of different accelerating structures and end-to-end beam dynamics simulations of the ACCIL will be presented.

Slides MOA4CO04 [3.531 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOA4CO04

Export •

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

TUPOA14

An Internet Rack Monitor-Controller for APS LINAC RF Electronics Upgrade

314

H. Ma, A. Nassiri, T.L. Smith, Y. Sun
ANL, Argonne, Illinois, USA
L.R. Doolittle, A. Ratti
LBNL, Berkeley, California, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences
To support the current research and development in APS LINAC area, the existing LINAC rf control performance needs to be much improved, and thus an upgrade of the legacy LINAC rf electronics becomes necessary. The proposed upgrade plan centers on the concept of using a modern, network-attached, rack-mount digital electronics platform 'Internet Rack Monitor-Controller (or IRMC) to replace the existing analog ones on the legacy crate/backplane-based hardware. The system model of the envisioned IRMC is basically a 3-tier stack with a high-performance processor in the mid- layer to handle the general digital signal processing (DSP). The custom FPGA IP's in the bottom layer handle the high-speed, real-time, low-latency DSP tasks, and provide the interface ports. A network communication gateway, in conjunction with an embedded event receiver (EVR), in the top layer merges the Internet Rack Monitor-Controller device into the networks of the accelerator controls infrastructure. Although the concept is very much in trend with today's Internet-of-Things (IoT), this implementation has actually been used in accelerators for over two decades.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA14

Export •

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

TUB3CO04

A New Thermionic RF Electron Gun for Synchrotron Light Sources

453

S.V. Kutsaev, A.Y. Murokh, E.A. Savin, A.Yu. Smirnov, A.V. Smirnov
RadiaBeam Systems, Santa Monica, California, USA
R.B. Agustsson, J.J. Hartzell, A. Verma
RadiaBeam, Santa Monica, California, USA
A. Nassiri, Y. Sun, G.J. Waldschmidt, A. Zholents
ANL, Argonne, Illinois, USA
E.A. Savin
MEPhI, Moscow, Russia

Funding: This work is supported by the U.S. Department of Energy, Office of Basic Energy Science, under contract DE-SC0015191 and contract No. DE-AC02-06CH11357.
A thermionic RF gun is a compact and efficient source of electrons used in many practical applications. RadiaBeam Systems and the Advanced Photon Source of Argonne National Laboratory collaborate in developing of a reliable and robust thermionic RF gun for synchrotron light sources which would offer substantial improvements over existing thermionic RF guns and allow stable operation with up to 1A of beam peak current at a 100 Hz pulse repetition rate and a 1.5 μs RF pulse length. In this paper, we discuss the electromagnetic and engineering design of the cavity, and report the progress towards high power tests of the cathode assembly of the new gun.

Slides TUB3CO04 [2.661 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUB3CO04

Export •

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

WEPOA13

RF Design and Simulation of a Non-Periodic Lattice Photonic Band Gap (PBG) Accelerating Structure

716

N. Zhou, A. Nassiri
ANL, Argonne, Illinois, USA

Photonic Band Gap (PBG) structures (metallic and or dielectric) have been proposed for accelerators. These structures act like a filter, allowing RF field at some frequencies to be transmitted through, while rejecting RF fields in some (unwanted) frequency range. Additionally PBG structures are used to support selective field patterns (modes) in a resonator or waveguide. In this paper, we will report on the RF design and simulation results of an X-band PBG structure, including lattice optimization, to improve RF performance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA13

Export •

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

WEPOB07

Dielectrically-Loaded Waveguide as a Short Period Superconducting Microwave Undulator

897

R. Kustom, A. Nassiri, K.J. Suthar, G.J. Waldschmidt
ANL, Argonne, Illinois, USA

The HEM12 mode in a cylindrical, dielectrically-loaded waveguide provides E and H fields on the central axis that are significantly higher than the fields on the conducting walls. The waveguide is designed to operate near its cutoff frequency where the wavelength and phase velocity vary significantly to enable tuning of the equivalent undulator wavelength. The operating frequency would range from 18 - 24 GHz. It would be possible to generate coherent, high-energy 45 - 65 KeV x-rays from the fundamental mode which are tunable over a 20% energy range by changing the source frequency while maintaining constant field strengths. The x-ray brilliance of the microwave undulator would be 3 times higher at 56-KeV and 7 times higher at 66 KeV than what is available with the APS 1.8 cm period Superconducting Wire Undulator. Since the loss factor of sapphire is very low at cryogenic temperatures, it is possible to consider a superconducting microwave undulator, although resistive losses of ~200 to 700 W/m may be a bit too high for CW operation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB07

Export •

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