F-Centre photoelectric materials as image storage targets

Abstract

Photoemission from colour centres in KCl, KI, CsCl, and CsBr has been measured for the first time in ultrahigh vacuum Torr). Photostimulated emission produced by electron irradiation of 1 to 12 keV in CsCI and CsBr exceeded the dose required for their creation,showing that a multiplicative process occurs. This satisfies the main requirement, i.e., to contemplate the construction of a low-level image detector competitive with existing tubes. The photoemission spectrum of CsCl a t room temperature shows structure in the F-band. Es wurde die Photoemission aus Farbzentren in KCl, KJ, CsCl und CsBr zum erstenmal im Ultrahochvakuum Torr) gemessen. Die lichtstimulierte Emission infolge von Elektroneneinstrahlung von 1 bis 12 keV in CsCl und CsBr iiberstieg die Dosis fur deren Erzeugung und zeigte, da13 ein multiplikativer Prozess vorliegt. Dies erfiillt die Hauptforderung, namlich die Konstruktion eines ,,low-Level"-Bilddetektors in Konkurrenz mit existierenden Rohren. Das Photoemissionspektrum von CsCl bei Zimmertemperatur zeigt eine Struktur der F-Bande.

SELECTIVE ELECTRON EMISSION FROM F-CENTERS IN CsCl

“…-Recent reactivation of early investigations of electron emission from CsCl [l] covers the stationary electron ejection from valence states 121 as well as tlie decaying emission from localized F-center states [3], [4]. Special applications of electron storage in CsCl F-centers have been proposed for image storage devices [5]. After photon impact the F-electrons are generally emitted in a nonselective process [6].…”