IPAC2016 - List of Authors (Nanni, E.A.)

Paper	Title	Page
TUPMY030	Measurements of Transmitted Electron Beam Extinction through Si Crystal Membranes	1611
	E.A. Nanni, R.K. Li, C. Limborg, X. Shen, S.P. Weathersby SLAC, Menlo Park, California, USA W.S. Graves, R. Kirian, J. Spence, U. Weierstall Arizona State University, Tempe, USA
	A recently proposed method for the generation of relativistic electron beams with nanometer-scale current modulation requires diffracting relativistic electrons from a perfect crystal Si grating, accelerating the diffracted beam and imaging the crystal structure into the temporal dimension via emittance exchange. The relative intensity of the current modulation is limited by the ability to extinguish the transmitted beam via diffraction with a single-crystal Si membrane. In these preliminary experiments we will measure the extinction of the transmitted electron beam at zero scattering angle due to multiple Bragg scattering from a Si membrane with a uniform thickness of 340 nm at 2.35 MeV using the SLAC UED facility. The impact of beam divergence and charge density at the Si target will be quantified. The longevity of the Si membrane will also be investigated by monitoring the diffraction pattern as a function of time to observe the potential onset of damage to the crystal.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY030
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THPOR044	mm-Wave Standing-Wave Accelerating Structures for High-Gradient Tests	3884
	E.A. Nanni, M. Dal Forno, V.A. Dolgashev, J. Neilson, S.G. Tantawi SLAC, Menlo Park, California, USA S.C. Schaub MIT, Cambridge, Massachusetts, USA R.J. Temkin MIT/PSFC, Cambridge, Massachusetts, USA
	We present the design and parameters of single-cell accelerating structures for high-gradient testing at 110 GHz. The purpose of this work is to study the basic physics of ultrahigh vacuum RF breakdown in high-gradient RF accelerators. The accelerating structures consist of pi-mode standing-wave cavities fed with TM01 circular waveguide mode. The geometry and field shape of these accelerating structures is as close as practical to single-cell standing-wave X-band accelerating structures, more than 40 of which were tested at SLAC. This wealth of X-band data will serve as a baseline for these 110 GHz tests. The structures will be powered from a pulsed MW gyrotron oscillator. One MW of RF power from the gyrotron may allow us to reach a peak accelerating gradient of 400 MeV/m.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR044
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Measurements of Transmitted Electron Beam Extinction through Si Crystal Membranes

1611

E.A. Nanni, R.K. Li, C. Limborg, X. Shen, S.P. Weathersby
SLAC, Menlo Park, California, USA
W.S. Graves, R. Kirian, J. Spence, U. Weierstall
Arizona State University, Tempe, USA

A recently proposed method for the generation of relativistic electron beams with nanometer-scale current modulation requires diffracting relativistic electrons from a perfect crystal Si grating, accelerating the diffracted beam and imaging the crystal structure into the temporal dimension via emittance exchange. The relative intensity of the current modulation is limited by the ability to extinguish the transmitted beam via diffraction with a single-crystal Si membrane. In these preliminary experiments we will measure the extinction of the transmitted electron beam at zero scattering angle due to multiple Bragg scattering from a Si membrane with a uniform thickness of 340 nm at 2.35 MeV using the SLAC UED facility. The impact of beam divergence and charge density at the Si target will be quantified. The longevity of the Si membrane will also be investigated by monitoring the diffraction pattern as a function of time to observe the potential onset of damage to the crystal.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY030

Export •

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

THPOR044

mm-Wave Standing-Wave Accelerating Structures for High-Gradient Tests

3884

E.A. Nanni, M. Dal Forno, V.A. Dolgashev, J. Neilson, S.G. Tantawi
SLAC, Menlo Park, California, USA
S.C. Schaub
MIT, Cambridge, Massachusetts, USA
R.J. Temkin
MIT/PSFC, Cambridge, Massachusetts, USA

We present the design and parameters of single-cell accelerating structures for high-gradient testing at 110 GHz. The purpose of this work is to study the basic physics of ultrahigh vacuum RF breakdown in high-gradient RF accelerators. The accelerating structures consist of pi-mode standing-wave cavities fed with TM01 circular waveguide mode. The geometry and field shape of these accelerating structures is as close as practical to single-cell standing-wave X-band accelerating structures, more than 40 of which were tested at SLAC. This wealth of X-band data will serve as a baseline for these 110 GHz tests. The structures will be powered from a pulsed MW gyrotron oscillator. One MW of RF power from the gyrotron may allow us to reach a peak accelerating gradient of 400 MeV/m.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR044

Export •

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