The investigation of two different photocathodes (PCs) based on nanodiamond (ND) layers, irradiated by a KrF nanosecond excimer laser (wavelength, λ=248 nm; photon energy, EPh=5 eV) is reported. The ND layers were deposited by means of a pulsed spray technique. Specifically, the active layer of each PC consisted of untreated (as-received) and hydrogenated ND particles, 250 nm in size, sprayed on a p-doped silicon substrate. The ND-based photocathodes were tested in a vacuum chamber at 10-6 mbar and compared to a Cu-based one, used as reference. All the photocathodes were irradiated at normal incidence. The quantum efficiency (QE) of the photocathodes was assessed. QE values of the ND-based photocathodes were higher than that of the reference one. In particular, the hydrogenated ND-based PC exhibited the highest QE due to the negative electron affinity that results from the surface terminated by hydrogen. Additionally, the photocathode surface/local temperature and the multiphoton process contribution to the electron emission were studied.
Titolo: | Electron beams produced by innovative photocathodes based on nanodiamond layers |
Autori: | NASSISI, Vincenzo [Membro del Collaboration Group] |
Data di pubblicazione: | 2019 |
Rivista: | |
Abstract: | The investigation of two different photocathodes (PCs) based on nanodiamond (ND) layers, irradiated by a KrF nanosecond excimer laser (wavelength, λ=248 nm; photon energy, EPh=5 eV) is reported. The ND layers were deposited by means of a pulsed spray technique. Specifically, the active layer of each PC consisted of untreated (as-received) and hydrogenated ND particles, 250 nm in size, sprayed on a p-doped silicon substrate. The ND-based photocathodes were tested in a vacuum chamber at 10-6 mbar and compared to a Cu-based one, used as reference. All the photocathodes were irradiated at normal incidence. The quantum efficiency (QE) of the photocathodes was assessed. QE values of the ND-based photocathodes were higher than that of the reference one. In particular, the hydrogenated ND-based PC exhibited the highest QE due to the negative electron affinity that results from the surface terminated by hydrogen. Additionally, the photocathode surface/local temperature and the multiphoton process contribution to the electron emission were studied. |
Handle: | http://hdl.handle.net/11587/437725 |
Appare nelle tipologie: | Articolo pubblicato su Rivista |