Holographic method coupled with an optoelectronic interface applied in the ionizing radiation dosimetry

The paper presents a holographic method applied in the ionizing radiation dosimetry. It is possible to use two types of holographic interferometry like as double exposure holographic interferometry, or fast real time holographic interferometry. In this paper the applications of holographic interferometry to ionizing radiation dosimetry are presented. The determination of the accurate value of dose delivered by an ionizing radiation source (released energy per mass unit) is a complex problem which imposes different solutions depending on experimental parameters and it is solved with a double exposure holographic interferometric method associated with an optoelectronic interface and Z80 microprocessor. The method can determine the absorbed integral dose as well as the three-dimensional distribution of dose in given volume. The paper presents some results obtained in radiation dosimetry. Original mathematical relations for integral absorbed dose in irreversible radiolyzing liquids where derived. Irradiation effects can be estimated from the holographic fringes displacement and density. To measure these parameters, the obtained holographic interferograms were picked-up by a closed TV circuit system in such a way that a selected TV line explores the picture along the direction of interest using a special designed interface, a Z80 and our microprocessor system captures data along the selected TV line. When the integral dose is to be measured the microprocessor computes it from the information contained in the fringes distribution, according to the proposed formulae. Integral absorbed dose and spatial dose distribution can be estimated with an accuracy better than 4%. Some advantages of this method are outlined comparatively with conventional method in radiation dosimetry. The paper presents an original holographic set-up with an electronic interface, assisted by a Z80 microprocessor and used for nondestructive testing of transparent objects at the laser wave length contained in the equipment. The gas laser is a low power He-Ne laser (3-5 mW). The use of holographic interferometry in the investigation of the material parameters and realisation of a nondestructive test has the advantage of high accuracy and increased speed in gatting the results do to addition of a microprocessor. An experimental montage design of holographic equipment is given in the paper. The holographic set-up is not expensive for it only consists of an unsophisticated parts. Different utilisations of this equipment are described with specifical results. The holographic method can be used in many applications of chemical dosimetry of ionizing radiations, biochemistry, biophysics, medical practice with fast paraclinical investigations. This paper presents an original technical procedure pattented and also some applications of holographic interferometry in radiation methodology (accuracy better than 1%). The holographic method is not expensive, but needs a dark room and isolated vibration table for experiments. The lasers used have low power and low price. (author)