Algird G. Leiga

X-RAY INDUCED HOLE TRAPPING IN ELECTRORADIOGRAPHIC PLATES

Changes in the electrical properties of pure a‐Se and Cl‐doped a‐Se:0.35% As electroradiographic layers upon exposure to x‐ray radiation has been examined using xerographic techniques based on the first residual potential VR1 and the cycled‐up residual potential VR∞ Hole lifetime τ as determined from the Warter expression VR1=L2/2μτ has been found to decrease sharply with the x‐ray dose, tending to saturate at higher dose levels in both pure a‐Se and Cl‐doped a‐Se:0.35%As. The hole liftime following x‐ray exposure recovers toward its equilibrium value at the anneal temperature. The recovery time is dependent on the dose and is accelerated appreciably by temperature, indicative of a thermally activated process. Cycled‐up xerographic residual‐potential measurements have indicated that the deep‐hole‐trap population increases with exposure to x rays.Comparison of cycled‐up saturated residual potential and first‐cycle residual‐potential measurements have shown that as a result of x‐ray exposure, the apparent c...

Optical Properties of Amorphous Selenium in the Vacuum Ultraviolet

The room-temperature reflectance of evaporated amorphous selenium films was obtained between 4 and 14.4 eV. The reflectance spectrum was the same for fresh samples evaporated onto substrates held at 10°, 24°, and 60°C; however, aged selenium films had a 25% lower reflectance between 9 and 14 eV while between 4 and 5 eV the spectrum was the same as from a fresh film. Only the gross features of the spectrum of the amorphous films were similar to the monoclinic and trigonal crystalline forms, since almost all of the structure disappears in the amorphous spectrum when the long-range order of the crystal is lost. An analysis of the reflectance data using the Kramers–Kronig technique yielded the real (n) and imaginary (k) parts of the index of refraction, the real (∊1) and imaginary (∊2) parts of the dielectric constant, the absorption coefficient (α), and the energy-loss function (−Im∊−1).

Optical Properties of Trigonal Selenium in the Vacuum Ultraviolet

The optical properties of trigonal selenium single crystals between 4 and 14.4 eV have been determined for radiation polarized parallel to (E||c) and perpendicular to (E⊥c) the c axis of the crystal. A Kramers–Kronig analysis of the room-temperature specular-reflectivity data yielded the real (n) and imaginary (k) parts of the complex index of refraction, the real (∊1) and imaginary (∊2) parts of the complex dielectric constant, the absorption coefficient (α), and the energy-loss function (−Im∊−1) over this energy range for both E||c and E⊥c.

Polywater: An Attempt at Synthesis in a Gas Discharge

An attempt to produce polywater in a corona discharge in moist air was unsuccessful. However, the major product produced, nitric acid, has a midrange infrared spectrum which is strikingly similar to that reported for polywater. The Raman spectrum offers a better means of distinguishing between nitric acid and polywater than the infrared spectrum does.

Photoemission from Amorphous Selenium

Photoemission yield measurements were made on amorphous selenium from about 6 to 21 eV. The yield curve exhibits a change in slope at about 7.8 eV corresponding to a maximum in the imaginary dielectric constant. The photoemission threshold is obtained by using a threshold law equation derived by Kane, Y = C (E − Et)n, where Y is the yield, E and Et are the photon energy and threshold energy, and C and n are constants. The yield data up to 8 eV are best represented by the equation with n=52 resulting in an extrapolated photoemission threshold of 5.86 eV for amrophous selenium.

Enhancement of the 2062-Å Atomic-Iodine Line in an Iodine Inert-Gas Flashlamp

The spectral output of flash-discharge lamps containing iodine, and mixtures of iodine and the inert gases were studied at selected wavelengths and discharge voltages. It was found that addition of xenon or krypton to iodine produced a marked enhancement of the 2062-A iodine line compared to the output from a pure iodine discharge. The enhancement of this line was found to be a maximum at approximately 130 torr and 3.0-kV discharge voltage with either of the inert gases. An enhancement factor of about 400 was found with added xenon and about 700 for a lamp filling containing krypton. It was postulated that, with xenon, energy-transfer collisions between metastable xenon and ground-state iodine atoms were responsible for the enhanced 2062-A radiation. With krypton–iodine mixtures an additional mechanism for producing excited iodine atoms was the reaction of metastable krypton atoms with iodine molecules producing one ground-state iodine atom and one in the 6p4P3/2 state.