New Photocathode materials for electron-ion-colliders

Lukaszew, Rosa A.¹ 

[1] College of William and Mary, Williamsburg, VA (United States)

关键词: photocathodes;    plasmonics;    spin-polarized;   

DOI  :  10.2172/1171112
RP-ID  :  WM--SC0008546-1
PID  :  OSTI ID: 1171112

学科分类：核物理和高能物理

美国|英语

来源: SciTech Connect

【 摘 要 】

Our aim has been to explore new photocathode materials and schemes to develop strategies and technologies for next generation nuclear physics accelerator capabilities, particularly for Electron Ion Colliders (EIC). Thus, we investigated thin film deposition and ensuing properties for several adequate magnetic materials applicable to spin-polarized photocathodes. We also implemented a full experimental setup for light incidence at an acute angle onto the photocathode surface in order to excite surface Plasmon resonance hence increasing light absorption by a metallic surface. We successfully tested the setup with a thermionic cathode as well as Plasmonic silver-MgO samples and obtained very encouraging results. Our first results are very encouraging since the photocurrent measured on this preliminary plasmonic Ag-MgO sample under low power (~ 1mW) cw red light from a HeNe laser was 256 pA, thus two orders magnitude larger than that reported by others following also plasmonic approaches. We extended our studies to shorter wavelengths and we also started preliminary work on chemically ordered MnAl thin films ???a component of the tertiary Ag-Mn-Al (silmanal) alloy in order to develop spin-polarized photocathodes capable of sustaining surface Plasmon resonance. It is worthwhile mentioning that a graduate student has been directly involved during this project ensuring the training of next generation of scientists in this area of research.