Characteristics of a silicon semiconductor detector in high en e rgy electron fields were studied. The output of detector in dose rate shows linearity up to 400R/min. The decrease in relative sensitivity induced by radiation damage is about 5% with the irradiation of 200 Gy. The detector shows the maximum sensitivity at the direction of 60° and the minimum at 90°.
The depth dose curves from the semiconductor detector agree with those from a shallow ionization chamber except for the build-up regions. Several paramerters, which chracterize the quality of the electron beam showed good agereement between semiconductor detector and shallow ionization chamber.

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A function to express depthdose curves of electron beams in the water phantom is given. This function is free from the deficiencies of the function recently proposed by Meigooni and Das. The function has been tested mainly by fitting it to the Monte-Carlo data reported by Berger and Seltzer. An energy-dependent expression obtained for the broad-beam depthdose curve reproduces the data in the energy region from 1 to 60 MeV within 2N. The Monte-Carlo data for central-axis depthdose curves of narrow beams could also be reproduced well. An example of fit to the central-axis depthdose curve specific to machine conditions is also given. The results of the test indicate that the function would be useful for electron-beam treatment planning.

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In this paper, a new 3-D TV system of “Spatial and time sharing threedimensional view TV” and its applications for X-ray, MR, RI and US imaging system are presented.
Characteristics of distortion for threedimensional seen about this 3-D TV system is explained by theoretical formula, and characteristics of this 3-D TV system is compared with other 3-D or stereoscopic TV systems.
The basic metho d of this 3-D TV system was also demonstrated experimentally.

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Absorbed dose conversion factors, Cλ, for several types of commercially available cylindrical chamber for photon beams with quality varying between ⁶⁰Co γ rays and 20 MV X rays were calculated according to a new Japanese Association of Radiological Physicists (JARP) protocol. The new protocol C, takes account of differences between the compositions of the chamber wall and the buildup cap. For 10 MV X rays, the Cλ for NE 2581 chamber having a wall of A-150plastic and Lucentine build-up cap is different 1.2% from that for JARP chamber having a wall and buildup cap of acrylic plastics. In order to determine the consistency of the absorbed dose given according to the JARP protocol, absorbed doses were determined under the reference condition in a phantom irradiated by ⁶⁰Coγ rays, and 4.2 and 8.5 MV X rays, using seven types of ionization chamber. The range of variation of the absorbed doses obtained was less than 1.1%for all investigated beam qualities. The ionization chamber readings were converted also to absorbed doses according to the American Association of Physicists in Medicine (AAPM) protocol. These absorbed doses showed good agrement, within 0.7% with absorbed doses obtained using the JARP protocols

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