TY - JOUR
T1 - Ultrafast laser pulse heating of metallic photocathodes and its contribution to intrinsic emittance
AU - Maxson, J.
AU - Musumeci, P.
AU - Cultrera, L.
AU - Karkare, S.
AU - Padmore, H.
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - The heating of the electronic distribution of a copper photocathode due to an intense drive laser pulse is calculated under the two-temperature model using fluences and pulse lengths typical in RF photoinjector operation. Using the finite temperature-extended relations for the photocathode intrinsic emittance and quantum efficiency, the time-dependent emittance growth due to the same photoemission laser pulse is calculated. This laser heating is seen to limit the intrinsic emittance achievable for photoinjectors using short laser pulses and low quantum efficiency metal photocathodes. A pump-probe photocathode experiment in a standard 1.6 cell S-band gun is proposed, in which simulations show the time dependent thermal emittance modulation within the bunch from laser heating can persist for meters downstream and, in principle, be measured using a slice emittance diagnostic.
AB - The heating of the electronic distribution of a copper photocathode due to an intense drive laser pulse is calculated under the two-temperature model using fluences and pulse lengths typical in RF photoinjector operation. Using the finite temperature-extended relations for the photocathode intrinsic emittance and quantum efficiency, the time-dependent emittance growth due to the same photoemission laser pulse is calculated. This laser heating is seen to limit the intrinsic emittance achievable for photoinjectors using short laser pulses and low quantum efficiency metal photocathodes. A pump-probe photocathode experiment in a standard 1.6 cell S-band gun is proposed, in which simulations show the time dependent thermal emittance modulation within the bunch from laser heating can persist for meters downstream and, in principle, be measured using a slice emittance diagnostic.
KW - Photocathodes
KW - Photoinjectors
KW - Ultrafast heating
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U2 - 10.1016/j.nima.2016.08.032
DO - 10.1016/j.nima.2016.08.032
M3 - Article
AN - SCOPUS:84994193494
SN - 0168-9002
VL - 865
SP - 99
EP - 104
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
ER -