Extreme regimes of femtosecond photoemission from a copper cathode in a dc electron gun

P.L.E.M. Pasmans, D.C. Van Vugt, J.P. van Lieshout, G.J.H. Brussaard, O.J. Luiten

Research output: Contribution to journalArticleAcademicpeer-review

3 Citations (Scopus)
79 Downloads (Pure)

Abstract

The femtosecond photoemission yield from a copper cathode and the emittance of the created electron beams has been studied in a 12 MeV/m, 100 keV dc electron gun over a wide range of laser fluence, from the linear photoemission regime until the onset of image charge limitations and cathode damaging. The measured photoemission curves can be described well with available theory which includes the Schottky effect, second-order photoemission, and image charge limitation. The second-order photoemission can be explained by thermally assisted one-photon photoemission (1PPE) and by above-threshold two-photon photoemission (2PPE). Measurements with a fresh cathode suggest that the 2PPE process is dominant. The beam emittance has been measured for the entire range of initial surface charge densities as well. The emittance measurements of space-charge dominated beams can be described well by an envelope equation with generalized perveance. The dc gun produces 0.1 pC bunches with 25 nm rms normalized emittance, corresponding to a normalized brightness usually associated with rf photoguns. In this experimental study the limits of femtosecond photoemission from a copper cathode have been explored and analyzed in great detail, resulting in improved understanding of the underlying mechanisms.

Original languageEnglish
Article number103403
Number of pages12
JournalPhysical Review Accelerators and Beams
Volume19
Issue number10
DOIs
Publication statusPublished - 26 Oct 2016

Fingerprint

electron guns
photoelectric emission
cathodes
copper
emittance
perveance
photons
space charge
fluence
brightness
envelopes
electron beams
thresholds
curves

Cite this

@article{42f5064334c54118a462ed2cff2b037e,
title = "Extreme regimes of femtosecond photoemission from a copper cathode in a dc electron gun",
abstract = "The femtosecond photoemission yield from a copper cathode and the emittance of the created electron beams has been studied in a 12 MeV/m, 100 keV dc electron gun over a wide range of laser fluence, from the linear photoemission regime until the onset of image charge limitations and cathode damaging. The measured photoemission curves can be described well with available theory which includes the Schottky effect, second-order photoemission, and image charge limitation. The second-order photoemission can be explained by thermally assisted one-photon photoemission (1PPE) and by above-threshold two-photon photoemission (2PPE). Measurements with a fresh cathode suggest that the 2PPE process is dominant. The beam emittance has been measured for the entire range of initial surface charge densities as well. The emittance measurements of space-charge dominated beams can be described well by an envelope equation with generalized perveance. The dc gun produces 0.1 pC bunches with 25 nm rms normalized emittance, corresponding to a normalized brightness usually associated with rf photoguns. In this experimental study the limits of femtosecond photoemission from a copper cathode have been explored and analyzed in great detail, resulting in improved understanding of the underlying mechanisms.",
author = "P.L.E.M. Pasmans and {Van Vugt}, D.C. and {van Lieshout}, J.P. and G.J.H. Brussaard and O.J. Luiten",
year = "2016",
month = "10",
day = "26",
doi = "10.1103/PhysRevAccelBeams.19.103403",
language = "English",
volume = "19",
journal = "Physical Review Accelerators and Beams",
issn = "2469-9888",
publisher = "American Physical Society",
number = "10",

}

Extreme regimes of femtosecond photoemission from a copper cathode in a dc electron gun. / Pasmans, P.L.E.M.; Van Vugt, D.C.; van Lieshout, J.P.; Brussaard, G.J.H.; Luiten, O.J.

In: Physical Review Accelerators and Beams, Vol. 19, No. 10, 103403, 26.10.2016.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Extreme regimes of femtosecond photoemission from a copper cathode in a dc electron gun

AU - Pasmans, P.L.E.M.

AU - Van Vugt, D.C.

AU - van Lieshout, J.P.

AU - Brussaard, G.J.H.

AU - Luiten, O.J.

PY - 2016/10/26

Y1 - 2016/10/26

N2 - The femtosecond photoemission yield from a copper cathode and the emittance of the created electron beams has been studied in a 12 MeV/m, 100 keV dc electron gun over a wide range of laser fluence, from the linear photoemission regime until the onset of image charge limitations and cathode damaging. The measured photoemission curves can be described well with available theory which includes the Schottky effect, second-order photoemission, and image charge limitation. The second-order photoemission can be explained by thermally assisted one-photon photoemission (1PPE) and by above-threshold two-photon photoemission (2PPE). Measurements with a fresh cathode suggest that the 2PPE process is dominant. The beam emittance has been measured for the entire range of initial surface charge densities as well. The emittance measurements of space-charge dominated beams can be described well by an envelope equation with generalized perveance. The dc gun produces 0.1 pC bunches with 25 nm rms normalized emittance, corresponding to a normalized brightness usually associated with rf photoguns. In this experimental study the limits of femtosecond photoemission from a copper cathode have been explored and analyzed in great detail, resulting in improved understanding of the underlying mechanisms.

AB - The femtosecond photoemission yield from a copper cathode and the emittance of the created electron beams has been studied in a 12 MeV/m, 100 keV dc electron gun over a wide range of laser fluence, from the linear photoemission regime until the onset of image charge limitations and cathode damaging. The measured photoemission curves can be described well with available theory which includes the Schottky effect, second-order photoemission, and image charge limitation. The second-order photoemission can be explained by thermally assisted one-photon photoemission (1PPE) and by above-threshold two-photon photoemission (2PPE). Measurements with a fresh cathode suggest that the 2PPE process is dominant. The beam emittance has been measured for the entire range of initial surface charge densities as well. The emittance measurements of space-charge dominated beams can be described well by an envelope equation with generalized perveance. The dc gun produces 0.1 pC bunches with 25 nm rms normalized emittance, corresponding to a normalized brightness usually associated with rf photoguns. In this experimental study the limits of femtosecond photoemission from a copper cathode have been explored and analyzed in great detail, resulting in improved understanding of the underlying mechanisms.

UR - http://www.scopus.com/inward/record.url?scp=85011252553&partnerID=8YFLogxK

U2 - 10.1103/PhysRevAccelBeams.19.103403

DO - 10.1103/PhysRevAccelBeams.19.103403

M3 - Article

AN - SCOPUS:85011252553

VL - 19

JO - Physical Review Accelerators and Beams

JF - Physical Review Accelerators and Beams

SN - 2469-9888

IS - 10

M1 - 103403

ER -