No abstract available

[en] Two different types of SSNTDS CN-85B and L R-115 Type II B were used to record alpha tracks which were generated from eighteen curies of ²³⁸ Pu-⁹ Be neutron source that immersed in water phantom tank with a cylindrical shape. The source is located at Physics department, Faculty of Science, Prince of Songkla University. The films were placed radially in water phantom starting from the origin up to the distance 50 cm. with 5 cm. interval. After one week, the films were collected and etched with 2.5 N NaOH at 60 degrees C about 25 and 90 minutes etc. in order to enlarge the latent alpha registration tracks. The track density per unit area of each film was determined by optical microscope at 400 x magnifications. We found that L R-115 Type II B film is more sensitive to record alpha track than CN-85B film and we have used L R-115 Type II B film for further studies. The results showed that the profile of alpha track densities in the radial direction are in good agreement with neutron dose rate calculations using program ANISN under point source condition. This implies that a low cost films L R-115 Type II B can be used as a neutron dosimeter

[en] LiF doped with Mg, Cu and P(GR-200) is a new, high sensitivity TLD material which has aroused intense interest in the international dosimetric community. Many radiation facilities are now in the process of switching over part of their external dosimetry program to LiF:Mg,Cu,P (e.g. Los Alamos, Ontario Hydro and AECL, Canada). LiF: Mg,Cu,P has many significant dosimetric advantages over LiF:Mg,Ti (TLD-100), such as dosimetric accuracy and precision ( particularly at low dose levels), in all the major areas of application of TLD personnel, environmental and clinical dosimetry. The only significant drawback to GR-200 has been the well-documented transformation and loss in sensitivity of the material when annealed at temperatures above approximately 240 degree C. (authors)

[en] Alpha contamination is a common phenomena in radiation research laboratories and other sites. Training staff to properly detect and control alpha contamination, present special problems. In order to train health physics personnel, while using alpha sources, both the trainers and the trainees are inevitably exposed to alpha contamination. This fact of course, comes in conflict with safety principles. In order to overcome these difficulties, a training detector was developed, built and successfully tested. (authors)

[en] The device is intended for search and localization of gamma radiation sources. High-sensitivity CsI detector, microprocessor, sound signal system with varying frequency of a sound allow to find out sources of small activity (source of cesium 137 with activity 0.025 mCi is detected on distance 1 m, at search of special nuclear materials the device finds out 4.3 g of plutonium 239 on distance 2.4 m). The hermetic enclosure, the small sizes, absence of the high voltage block enable to use the device in extreme conditions

[en] The small-sized device is intended for the control by the population of radiation conditions and magnitude of the stored equivalent doze. A measurement range of doze rate of gamma radiation is 0.0001 - 0.0999 mSv/h. A measurement range of the stored equivalent doze is 0-0.999 mSv. An energy range of gamma radiation is 0.0595 - 1.25 MeV

[en] Complete text of publication follows. Various LiF TL dosemeters have been investigated for selective assessment of low and high LET radiation for space dosimetry purposes. The aim of these investigation was to compare the selectivity of the glow peaks on the Harshaw TLD-100, on the Polish LiF (types MTS-N and the newly developed LiF-1T, LiF-5T, LiF-10T) and on the Austrian LiF-F single crystal dosemeters using alpha, gamma and thermalized neutron radiation. Comparing the TL responses using glow curve analysis on the peaks 4-5 (190 deg - 210 deg) and on the high peaks 6-7 (250 deg - 270 deg) generated by high LET radiation, it was found that the separation based on the ratio of the low and high temperature peaks is the most promising in case of Polish LiF(MTS-N) and LiF-5T dosemeters. It suggests, that if one uses a single LiF dosemeter, selective assessment can be done of low and high LET space radiations. The method can be used as well for separate measurement of the fast neutron and gamma dose in a mixed radiation field using a single LiF dosemeter in a moderator sphere

[en] The SPLINE interpolation is a very suitable method for obtaining smooth interpolation curves. One of the basic advantages over the appropriate nonlinear fitting methods lies in its relatively simple machine applicability and a less complicated mathematical apparatus. Although the number of fitting parameters is in this case also a large one, machine time for SPLINE algorithm procedure is considerably shorter compared to the time standard procedures of nonlinear fitting (by the least squares method) require. In case of the SPLINE interpolation, the interpolation function is made of smoothly connected polynomials (usually the 3rd degree), where each of them is defined respectively on some of the sequential intervals so that the interpolation functions pass through each of the experimental points. In this paper, a modified algorithm of cubic discrete SPLINE interpolation was used for obtaining curve of an absolute efficiency factors, depending on energies of incident photon radiation at calibration of high purity germanium detector (HPGe Detector). (author)

[en] A commercially available 'label dosimeter' is intended for visual evaluation. The physical changes in colour and brightness are the basic changes on which subjective judgement relies. Change in brightness was chosen as the parameter of objective evaluation and a reader was developed. After test of an experimental set-up a prototype reader was developed and finally converted into an electronic hand-held instrument. This allows for reading of the code of a 'label dosimeter' giving information about its 'decision function' and the associated threshold dose value, reading the optical response of the particular 'label dosimeter' and converting this into a judgement about acceptance or rejection of the product lot under inspection. At present, such 'label dosimeters' are manufactured only for a limited set of threshold dose values. For commercial scale and international trade applications a wide range of such 'label dosimeters' need to be utilized. The electronic instrument developed in this study would allow for a great variety of such 'label dosimeters' to be evaluated by objective means and the results be recorded and transmitted for further evaluation by control authorities. (author)

[en] Aqueous solution of congored has been investigated spectrophotometrically for possible applications in food irradiation dosimetry. Absorption spectra of the solution showed two absorption bands with peaks at 346 and 498 nm. Radiation induced bleaching of the dye was measured at the wavelengths of maximum absorbance (346 and 498 nm) as well as at several other wavelengths (491, 540 and 570 nm). At 498 mn, the decrease in absorbance of the dosimeter was linear with respect to the absorbed dose from 50 to 600 Gy. At the other peak wavelength (346 mn), the response was linear up to 400 Gy, however, the upper limit was increased to 600 Gy when the response was measured at longer wavelengths (491, 540 or 570 mn). If the negative logarithm of the absorbance (-log A) at these wavelengths is plotted versus absorbed dose, a linear response was observed from 50 to 1200 Gy. Postirradiation stability of dosimetric solution was studied at room temperature and showed almost stable response up to 50 days when stored in dark. The response was found almost stable for 50 days when the solution after irradiation was exposed to white fluorescent light or to diffused sunlight inside the laboratory. The aqueous congored solution is unstable when exposed to direct sunlight, showing rapid decrease in absorbance for the first few hours followed by a slower decrease. The results suggest that the aqueous congored dosimeter with linear response up to 1200 Gy is suitable for a number of food irradiation applications, such as, sprout inhibition of potatoes, onion and garlic and for ripening delay and ripening stimulation of fruits and vegetables. (author)