Ionizing radiation is electromagnetic radiation that has sufficient energy to remove electrons from atoms. Ionization results in the production of negatively charged free electrons and positively charged ionized atoms. Ionizing radiation can be classified into two categories: photons (X-radiation and gamma radiation) and particles (alpha and beta particles and neutrons). Five types or sources o...

Interstellar dust contains a component which reveals its presence by emitting a broad, unstructured band of light in the 540 to 950 nm wavelength range, referred to as Extended Red Emission (ERE). The presence of interstellar dust and ultraviolet photons are two necessary conditions for ERE to occur. This is the basis for suggestions which attribute ERE to an interstellar dust component capable...

The hazard of ionizing radiation from internally administered colloidal thorium dioxide (Thorotrast) has been a subject of controversy even since this medium was first employed in clinical roentgenology. Reports of neoplasia as well as diffuse hepatic fibrosis occurring in patients following Thorotrast administration have been summarized and evaluated by Thomas et al.7 Although intravenous inje...

Various types of radiation detectors are used to measure relative dose distributions for therapeutic electron and photon beams. Most detectable signals from a radiation detector are correlated to the energy imparted δε to the detector [1]. This, in turn, is related to the absorbed dose in the detector, Ddet. Table I lists types of radiation detectors, their signals, and their relationship to th...

This report looks at the feasibility of detecting radiation sources by using the photons produced by the ionization of the air surrounding the source. Some of these fluorescence photons are emitted in the UV solar blind spectral region which offers the possibility of detection in full daylight. A review of the basic technique is given as well as detailed radiation source simulations using the G...

We present an easy-to-use formula for mean (spaceand direction-average) specific intensity of radiation in uniform spherical and cylindrical plasmas, which are not under external irradiation. This formula has high accuracy in any spectral interval dn taken in continuum as well as within a spectral line of any profile, including overlapping lines and lines on a pedestal of intense continuum in a...

Temporal widths of an attosecond (asec) XUV radiation pulse train, formed by the superposition of higher order harmonics, have been recently determined utilizing a 2nd order autocorrelation measurement. An assessment of the validity of the approach, for the broadband XUV radiation of asec pulses, is implemented through ab initio calculations modeling the spectral and temporal response of the tw...

A new large-area detector system was constructed at the University of Chicago for direct measurements of heavy cosmic ray nuclei (oxygen to iron) up to about 10 TeV/nucleon. TRACER (”Transition Radiation Array for Cosmic Energetic Radiation”) uses plastic scintillators to measure charge and a proportional tube array to measure energy via specific ionization and transition radiation. While TRACE...

We present the results of an experimental study multiphoton ionization in fused silica, using a linearly polarized femtosecond Satsuma fiber laser with active medium based on Yb+3 ions, at 515 -nm and 1030 wavelengths. The radiation transmission silica was measured as function intensity wavelength data were analyzed theoretical model Keldysh theory. determined absorption cross-sections case fou...

The Gammamed Plus 192Ir high dose rate brachytherapy sources were calibrated using the therapy level ionization chambers (0.1 and 0.6 cc) and the well-type chamber. The aim of the present study was to assess the accuracy and suitability of use of the therapy level chambers for in-air calibration of brachytherapy sources in routine clinical practice. In a calibration procedure using therapy ion ...