Performance of magnesium cathode in the S-band RF gun

T. Srinivasan-Rao; I. Ben-Zvi; J. Smedley; X. J. Wang; M. Woodle; D. T. Palmer; R. H. Miller

Performance of magnesium cathode in the S-band RF gun

T. Srinivasan-Rao
, I. Ben-Zvi
, J. Smedley
, X. J. Wang
, M. Woodle
, D. T. Palmer
, R. H. Miller

Physics and Astronomy

Brookhaven National Laboratory

Research output: Contribution to conference › Paper › peer-review

8 Scopus citations

Abstract

In this paper, we present the preliminary results of the performance of magnesium cathode in a high frequency RF gun. The quantum efficiency of Mg showed a dramatic improvement upon laser cleaning, increasing from 10^-5 to 4×10^-4 after two hours of cleaning, and to 2×10^-3 after systematic cleaning. The cleaning procedure for this increase is described in detail. Charge measured as a function of the laser injection phase relative to the RF phase indicates that the temporal variation of the field on the cathode both due to the RF and the shielding effect of the emitted electrons play a critical role in the emission and extraction of electrons. A model that includes this variation is numerically fitted to the measured charge and the results are presented. The unexpected outcome of the fit was the low field enhancement factor (0.1) predicted by the model for the photoemission. The physical origin of this is still under investigation.

Original language	English
Pages	2790-2792
Number of pages	3
State	Published - 1998
Event	Proceedings of the 1997 17th Particle Accelerator Conference, PAC-97 - Vancouver, BC, CAN Duration: May 12 1997 → May 16 1997

Conference

Conference	Proceedings of the 1997 17th Particle Accelerator Conference, PAC-97
City	Vancouver, BC, CAN
Period	05/12/97 → 05/16/97

Cite this

@conference{cb77d2c0ad364621bd0a9e2bd9964769,

title = "Performance of magnesium cathode in the S-band RF gun",

abstract = "In this paper, we present the preliminary results of the performance of magnesium cathode in a high frequency RF gun. The quantum efficiency of Mg showed a dramatic improvement upon laser cleaning, increasing from 10-5 to 4×10-4 after two hours of cleaning, and to 2×10-3 after systematic cleaning. The cleaning procedure for this increase is described in detail. Charge measured as a function of the laser injection phase relative to the RF phase indicates that the temporal variation of the field on the cathode both due to the RF and the shielding effect of the emitted electrons play a critical role in the emission and extraction of electrons. A model that includes this variation is numerically fitted to the measured charge and the results are presented. The unexpected outcome of the fit was the low field enhancement factor (0.1) predicted by the model for the photoemission. The physical origin of this is still under investigation.",

author = "T. Srinivasan-Rao and I. Ben-Zvi and J. Smedley and Wang, \{X. J.\} and M. Woodle and Palmer, \{D. T.\} and Miller, \{R. H.\}",

year = "1998",

language = "English",

pages = "2790--2792",

note = "Proceedings of the 1997 17th Particle Accelerator Conference, PAC-97 ; Conference date: 12-05-1997 Through 16-05-1997",

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TY - CONF

T1 - Performance of magnesium cathode in the S-band RF gun

AU - Srinivasan-Rao, T.

AU - Ben-Zvi, I.

AU - Smedley, J.

AU - Wang, X. J.

AU - Woodle, M.

AU - Palmer, D. T.

AU - Miller, R. H.

PY - 1998

Y1 - 1998

N2 - In this paper, we present the preliminary results of the performance of magnesium cathode in a high frequency RF gun. The quantum efficiency of Mg showed a dramatic improvement upon laser cleaning, increasing from 10-5 to 4×10-4 after two hours of cleaning, and to 2×10-3 after systematic cleaning. The cleaning procedure for this increase is described in detail. Charge measured as a function of the laser injection phase relative to the RF phase indicates that the temporal variation of the field on the cathode both due to the RF and the shielding effect of the emitted electrons play a critical role in the emission and extraction of electrons. A model that includes this variation is numerically fitted to the measured charge and the results are presented. The unexpected outcome of the fit was the low field enhancement factor (0.1) predicted by the model for the photoemission. The physical origin of this is still under investigation.

AB - In this paper, we present the preliminary results of the performance of magnesium cathode in a high frequency RF gun. The quantum efficiency of Mg showed a dramatic improvement upon laser cleaning, increasing from 10-5 to 4×10-4 after two hours of cleaning, and to 2×10-3 after systematic cleaning. The cleaning procedure for this increase is described in detail. Charge measured as a function of the laser injection phase relative to the RF phase indicates that the temporal variation of the field on the cathode both due to the RF and the shielding effect of the emitted electrons play a critical role in the emission and extraction of electrons. A model that includes this variation is numerically fitted to the measured charge and the results are presented. The unexpected outcome of the fit was the low field enhancement factor (0.1) predicted by the model for the photoemission. The physical origin of this is still under investigation.

UR - https://www.scopus.com/pages/publications/0032257142

M3 - Paper

AN - SCOPUS:0032257142

SP - 2790

EP - 2792

T2 - Proceedings of the 1997 17th Particle Accelerator Conference, PAC-97

Y2 - 12 May 1997 through 16 May 1997

ER -

Performance of magnesium cathode in the S-band RF gun

Abstract

Conference

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