Publication detail

Charge production studies from Cs2Te photocathodes in a normal conducting RF gun

Hernandez-Garcia, C. Krasilnikov, M. Asova, G. Bakr, M. Boonpornprasert, P. Good, J. Gross, M. Huck, H. Isaev, I. Kalantaryan, D. Khojoyan, M. Kourkafas, G. Lishilin, O. Malyutin, D. Melkumyan, D. Oppelt, A. Otevrel, M. Pathak, G. Renier, Y. Rublack, T. Stephan, F. Vashchenko, G. Zhao, Q.

Original Title

Charge production studies from Cs2Te photocathodes in a normal conducting RF gun

Type

journal article in Web of Science

Language

English

Original Abstract

This work discusses the behavior of electron bunch charge produced in an L-band normal conducting radio frequency gun from Cs2Te photocathodes illuminated with ps-long UV laser pulses and presumed homogeneous flattop laser transverse distribution. The measured charge shows the expected linear dependence in the quantum efficiency limited emission regime at low laser pulse energies. At higher laser pulse energy, the measured charge in the space charge limited emission regime should saturate, assuming an ideal homogeneous flattop laser transverse distribution. However, this behavior is not observed experimentally. Instead of saturating, the measured charge continues to increase with laser pulse energy, albeit with much weaker dependence than in the quantum efficiency limited emission regime. Simulations with the space charge particle tracking code ASTRA show that the charge saturates as expected using a homogeneous flattop laser transverse distribution. The discrepancy between simulations and measured excess charge may be attributed to the presence of unintentional Gaussian-like decaying radial halo beyond the core of the otherwise presumed homogeneous flattop core. The rate of increase of the measured charge at high laser pulse energies seems to be proportional to the amount of halo despite charge saturation in the core of the transverse laser radial profile. By utilizing core + halo particle distributions based on measured radial laser profiles, ASTRA simulations and semi-analytical emission models reproduce the behavior of the measured charge for a wide range of RF gun and laser operational parameters within the measurement uncertainties.

Keywords

RF electron guns Space charge Laser radial halo

Authors

Hernandez-Garcia, C.; Krasilnikov, M.; Asova, G.; Bakr, M.; Boonpornprasert, P.; Good, J.; Gross, M.; Huck, H.; Isaev, I.; Kalantaryan, D.; Khojoyan, M.; Kourkafas, G.; Lishilin, O.; Malyutin, D.; Melkumyan, D.; Oppelt, A.; Otevrel, M.; Pathak, G.; Renier, Y.; Rublack, T.; Stephan, F.; Vashchenko, G.; Zhao, Q.

Released

1. 11. 2017

ISBN

0168-9002

Periodical

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT

Year of study

871

Number

1

State

Kingdom of the Netherlands

Pages from

97

Pages to

104

Pages count

8

URL

https://www.sciencedirect.com/science/article/pii/S0168900217307040

BibTex

@article{BUT146381,
  author="Hernandez-Garcia, C. and Krasilnikov, M. and Asova, G. and Bakr, M. and Boonpornprasert, P. and Good, J. and Gross, M. and Huck, H. and Isaev, I. and Kalantaryan, D. and Khojoyan, M. and Kourkafas, G. and Lishilin, O. and Malyutin, D. and Melkumyan, D. and Oppelt, A. and Otevrel, M. and Pathak, G. and Renier, Y. and Rublack, T. and Stephan, F. and Vashchenko, G. and Zhao, Q.",
  title="Charge production studies from Cs2Te photocathodes in a normal conducting RF gun",
  journal="NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT",
  year="2017",
  volume="871",
  number="1",
  pages="97--104",
  doi="10.1016/j.nima.2017.06.051",
  issn="0168-9002",
  url="https://www.sciencedirect.com/science/article/pii/S0168900217307040"
}