TY - GEN
T1 - Field assisted photoemission from nanocrystalline diamond and diamond field emitter arrays
AU - Pavlenko, Vitaly
AU - Andrews, Heather Lynn
AU - Aragonez, Robert J
AU - Fleming, Ryan L.
AU - Huang, Chengkun
AU - Kim, Dongsung
AU - Kwan, Thomas J T
AU - Piryatinski, Andrei
AU - Simakov, Evgenya Ivanovna
PY - 2019/3/4
Y1 - 2019/3/4
N2 - Field emission from nanocrystalline diamond and especially from diamond field emitters is known to have an onset at low electric fields of a few MV/m, although the discussion on the agreement of the results with the classical Fowler-Nordheim model is still pending. While measurements of pure photoemission from flat nanocrystalline diamond agree reasonably well with the 3-step photoemission model for the wide bandgap semiconductor with low electron affinity, we are not aware of systematic studies of photoemission in the 0.1-5 MV/m range, where the electron emission mechanism is expected to be affected by the Schottky effect and crossover with the field emission. In order to understand applicability of field enhanced photoemission from diamond to generation of bright coherent photo-gated electron beams suitable for dielectric laser accelerators, we have designed a system to measure spectral response (quantum efficiency vs wavelength) of mm-sized samples with up to 5 MV/m electric field in the anode-cathode gap. The system is based on an incoherent Xe lamp-based tunable ultaviolet light source, therefore relatively large and dense diamond field emitter arrays are required for comparative studies of arrays versus flat nanocrystalline diamond samples. We present the results of our original measurements in the range between 195 nm and 270 nm. Potential schemes of laser-triggered photoemission from a single diamond field emitter tip are discussed in view of the obtained results.
AB - Field emission from nanocrystalline diamond and especially from diamond field emitters is known to have an onset at low electric fields of a few MV/m, although the discussion on the agreement of the results with the classical Fowler-Nordheim model is still pending. While measurements of pure photoemission from flat nanocrystalline diamond agree reasonably well with the 3-step photoemission model for the wide bandgap semiconductor with low electron affinity, we are not aware of systematic studies of photoemission in the 0.1-5 MV/m range, where the electron emission mechanism is expected to be affected by the Schottky effect and crossover with the field emission. In order to understand applicability of field enhanced photoemission from diamond to generation of bright coherent photo-gated electron beams suitable for dielectric laser accelerators, we have designed a system to measure spectral response (quantum efficiency vs wavelength) of mm-sized samples with up to 5 MV/m electric field in the anode-cathode gap. The system is based on an incoherent Xe lamp-based tunable ultaviolet light source, therefore relatively large and dense diamond field emitter arrays are required for comparative studies of arrays versus flat nanocrystalline diamond samples. We present the results of our original measurements in the range between 195 nm and 270 nm. Potential schemes of laser-triggered photoemission from a single diamond field emitter tip are discussed in view of the obtained results.
UR - https://www.scopus.com/pages/publications/85063512860
U2 - 10.1109/AAC.2018.8659444
DO - 10.1109/AAC.2018.8659444
M3 - Conference contribution
T3 - 2018 IEEE Advanced Accelerator Concepts Workshop, ACC 2018 - Proceedings
BT - 2018 IEEE Advanced Accelerator Concepts Workshop, ACC 2018 - Proceedings
PB - Unknown Publisher
T2 - 18th IEEE Advanced Accelerator Concepts Workshop, ACC 2018
Y2 - 4 March 2019
ER -