[en] Some ions produced in a cavity ionization chamber diffuse to the surface of an electrode of the same polarity as their charge, and they therefore do not contribute to the signal current. An equation for the diffusion loss of ions in parallel plate ionization chambers was derived by Langevin some time ago. It has been confirmed experimentally for air at various humidities that the decrease in output current agrees precisely with values obtained from the equations. In previous papers, we have derived both exact and approximate equations for back diffusion loss of ions in cylindrical and spherical ionization chambers. In this paper, we measure saturation curves for cylindrical ionization chambers to confirm the validity of the equation After correcting for volume recombination and also for small initial recombination, experimentally obtained diffusion losses are compared with the values obtained from the equations. (authors)

[en] Our purpose was to carry out dosimetric evaluation of methods of Colon roentgenologic examination. their comparative analysis and search for ways of reducing the X-ray exposure dose to patients keeping high imaging and diagnostic criteria (authors)

[en] Personnel who perform interventional radiological procedures which involve long fluoroscopy times and with a high workload, may receive radiation doses comparable to one of the dose limits suggested by the International Commission on Radiological protection. It is therefore important to monitor accurately the radiation dose to every staff member. who is involved in fluoroscopy procedures. (authors)

[en] Abstract Radioactivity concentration of ²³⁸U in a phosphate ores quarry was measured in situ. Independently, soil samples collected in the site were measured in the laboratory. It was disclosed that radon emanation from the soil lowers in situ results that are derived from radon daughters. Uranium concentration was found to be 121.6±1.9 mg kg^-1 (authors)

[en] The Airborne Radiation Monitoring System monitors radioactive contamination in the air or on the ground. The contamination source can be a radioactive plume or an area contaminated with radionuclides. This system is composed of two major parts: Airborne Unit carried by a helicopter, and Ground Station carried by a truck. The Airborne software is intended to be the core of a computerized airborne station. The software is written in C++ under MS-Windows with object-oriented methodology. It has been designed to be user-friendly: function keys and other accelerators are used for vital operations, a help file and help subjects are available, the Human-Machine-Interface is plain and obvious. (authors)

[en] A common requirement of modern real-time radiation monitoring and visualization systems is the ability to display the current regional distribution of radiation. This paper reviews an algorithm developed for real-time radiation plume contouring, as a part of a complete airborne monitoring system. The algorithm allows for detailed portrayal of radiation distribution, derived from a. finite set of radiation samples. (authors)

[en] One of the major sources of uncertainty in the measurement of low radiation doses with LiF:Mg,Ti TLDs is the presence of background thermoluminescence in an annealed dosimeter (i.e., thermoluminescence not due to previously absorbed ionizing radiation). This background thermoluminescence can be caused by various disturbing effects and gives a signal similar to the thermoluminescent signal caused by ionizing radiation. Several papers presented some cases of disturbing effects ( 1-6) , which give rise to such background thermoluminescence. Glow curves of thermoluminescent dosemeters contain useful information that can improve accuracy and reliability of TL measurements . The influence of various disturbing effects can be recognized in the shape of glow curves and sometimes can be separated from the exposure reformation . In the present work we are presenting some abnormal glow curves of LiF:Mg,Ti TLD cards. From the shape of the glow curves, as well as from the relatively high second readings ( these cards, we can assume that a part of their signal is caused by disturbing effects (not by ionizing radiation). The separation of the contribution of the ionizing radiation from the total thermoluminescent signal, using glow curve deconvolution, is presented for some cases. (authors)

[en] The Israel Dosimetry Center, operated by the Radiation Safety Department at Soreq NRC, serves approximately 10,000 radiation workers throughout the country. Workers in medical, educational and industrial installations are monitored monthly or bi-monthly for external ionizing radiations: X- and gamma rays, beta radiation, anti thermal and fast neutrons. Dosimetry of all but the last category is performed by TLD (Thermo Luminescence Dosimeter) badges (chest, head, hand, leg) or TLD rings. Fast neutrons exposures are measured by CR-39 track etch detector. The reporting level was 0.2 mSv/month for gamma - and X-radiation until 1993 and has been 0. 1 mSv/month since then. This document constitutes a summary of the occupational exposures (whole-body only, i.e., chest) during the period 1991-1996. Table 1 provides information on the number of monitored workers, the annual collective effective dose, and the average annual effective individual dose per monitored worker and per measurably exposed worker (above the recording level of 0.2 mSv or 0.1 mSv, respectively, at least once a year). The last two columns are the dose distribution ratios, with NR₁₅ being the fraction of the work-force exposed annually to 15 mSv or more and MR₁₅ the fraction of the annual collective dose delivered to this population. (authors)

[en] A system, based on a new concept of controlling and monitoring distributed radiation monitors, has been developed and approved at the NRCN. The system, named ^BAKNET Network^, consists of a series of communication adapters connected to a main PC via an RS-485 communication network (see Fig. 1). The network's maximal length is 1200 meters and it enables connection of up to 128 adapters. The BAKNET adapters are designed to interface output signals of different types of stationary radiation monitors to a main PC. The BAKNET adapters' interface type includes: digital, analog, RS-232, and mixed output signals. This allows versatile interfacing of different stationary radiation monitors to the main computer. The connection to the main computer is via an RS-485 network, utilizing an identical communication protocol. The PC software, written in C ++ under MS-Windows, consists of two main programs. The first is the data collection program and the second is the Human Machine Interface (HMI). (authors)

[en] A high range gamma meter mounted on a telescopic pole was developed in order to obtain readings in high radiation fields and hard-to-reach areas (i.e. vehicle surveys, elevated piping). (authors)