A new type of gas counter with a backgammon electrode is developed. The counter can achieve two-dimensional position sensing with the backgammon electrode read-out for one coordinate and the drift time read-out for another coordinate. This counter is designed for use as a transmission type position sensitive detector in a charged particle detecting system that consists of NaI(Tl) crystals. The sensitive region of the counter is about 70x70 mm² and the position resolutions are less then 0.9 mm in full width at half maximum for both coordinates.

  Absorbed dose measurements of the insulating material for 29GeV TRISTAN Main-Ring magnets were carried out with the Infrared spectrometry. From the fact that carbonyl radical is induced in epoxy resin by irradiation, infrared absorbance in the range of 1705-1720 cm¹ due to carbonyl radicals was applied to the estimations of the absorbed dose of the epoxy resin. Relationship between absorbance of carbonyl band and absorbed dose was investigated exposing the epoxy resin in two irradiation fields, TRISTAN MR and irradiation facility of 3kCi ⁶⁰Co source. From this work, it was found that IR absorbance method could be applied to the absorbed dose measurements from 10³ to 10⁷ Gy and that absorbed doses obtained from 31 specimens of epoxy resin shaved from coils of TRISTAN MR magnets had a distribution extending from 2.6×10³ to 1.07×10⁷ Gy, mostly order of 10⁴ to 10⁵ Gy.