PAC2013 - List of Authors (Moore, T.P.)

Paper

Title

Page

A Fast Rotating Wire Scanner for use in High Current Accelerators

385

S.J. Full, N.I. Agladze, A.C. Bartnik, I.V. Bazarov, J. Dobbins, B.M. Dunham, Y. Li, X. Liu, T.P. Moore, J.J. Savino, K.W. Smolenski
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: This work was supported by the financial assistance from the National Science Foundation (Grant No. DMR-0807731).}
We have developed a cost-effective, fast rotating wire scanner for use in accelerators where high beam currents would otherwise melt even carbon wires. This new design uses a simple planetary gear setup to rotate a carbon wire, fixed at one end, through the beam at speeds in excess of 20 m/s. We will present results from bench tests, as well as transverse beam profile measurements taken at Cornell's high-brightness ERL photoinjector, for a beam energy of 4 MeV and currents up to 35 mA.

Slides TUOBA1 [8.870 MB]

TUOAB1

Advances in Photocathode Technology at Cornell University

391

S.S. Karkare
Cornell University, Ithaca, New York, USA
I.V. Bazarov, L.E. Boulet, M. Brown, L. Cultrera, B.M. Dunham, N. Erickson, G. Gabriel, A. Kim, B. Lillard, T.P. Moore, C. Nguyen, W.J. Schaff, K.W. Smolenski, H. Wang
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: This work has been funded by NSF under grant number DMR-0807731, DOE under grant number DE-SC0003965
Beam brightness from modern day photoinjectors is limited by the photocathode. A multifaceted photocathode development program has been undertaken at Cornell University with a goal to develop the ultimate photocathode which has high quantum efficiency, low mean transverse energy, quick response time and a long lifetime. Positive affinity cathodes like CsK2Sb and NaK2Sbhave been grown using different kinds of alkali metal sources (alkali-azide and pure metal) , characterized and tested in the Cornell-ERL photoinjector. Novel layered structures of various III-V semiconductors like GaAs and AlGaAs grown using Molecular Beam Epitaxy and activated to negative electron affinity using Cs and NF3 are also being investigated. Surface and photoemission diagnostics like Auger spectroscopy, LEED, RHEED and the 2D-electron energy analyzers have been connected in vacuum to the photocathode growth and preparation chambers to fully characterize the surface and emission properties of the materials grown. A Monte Carlo based simulation has also been developed to predict photoemission from layered semiconductor structures and help design novel structures to optimize the photoemission properties.

Slides TUOAB1 [6.005 MB]

Paper	Title	Page
TUOBA1	A Fast Rotating Wire Scanner for use in High Current Accelerators	385
	S.J. Full, N.I. Agladze, A.C. Bartnik, I.V. Bazarov, J. Dobbins, B.M. Dunham, Y. Li, X. Liu, T.P. Moore, J.J. Savino, K.W. Smolenski Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: This work was supported by the financial assistance from the National Science Foundation (Grant No. DMR-0807731).} We have developed a cost-effective, fast rotating wire scanner for use in accelerators where high beam currents would otherwise melt even carbon wires. This new design uses a simple planetary gear setup to rotate a carbon wire, fixed at one end, through the beam at speeds in excess of 20 m/s. We will present results from bench tests, as well as transverse beam profile measurements taken at Cornell's high-brightness ERL photoinjector, for a beam energy of 4 MeV and currents up to 35 mA.
	Slides TUOBA1 [8.870 MB]

TUOAB1	Advances in Photocathode Technology at Cornell University	391
	S.S. Karkare Cornell University, Ithaca, New York, USA I.V. Bazarov, L.E. Boulet, M. Brown, L. Cultrera, B.M. Dunham, N. Erickson, G. Gabriel, A. Kim, B. Lillard, T.P. Moore, C. Nguyen, W.J. Schaff, K.W. Smolenski, H. Wang Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: This work has been funded by NSF under grant number DMR-0807731, DOE under grant number DE-SC0003965 Beam brightness from modern day photoinjectors is limited by the photocathode. A multifaceted photocathode development program has been undertaken at Cornell University with a goal to develop the ultimate photocathode which has high quantum efficiency, low mean transverse energy, quick response time and a long lifetime. Positive affinity cathodes like CsK2Sb and NaK2Sbhave been grown using different kinds of alkali metal sources (alkali-azide and pure metal) , characterized and tested in the Cornell-ERL photoinjector. Novel layered structures of various III-V semiconductors like GaAs and AlGaAs grown using Molecular Beam Epitaxy and activated to negative electron affinity using Cs and NF3 are also being investigated. Surface and photoemission diagnostics like Auger spectroscopy, LEED, RHEED and the 2D-electron energy analyzers have been connected in vacuum to the photocathode growth and preparation chambers to fully characterize the surface and emission properties of the materials grown. A Monte Carlo based simulation has also been developed to predict photoemission from layered semiconductor structures and help design novel structures to optimize the photoemission properties.
	Slides TUOAB1 [6.005 MB]