U-スコープ
1958 年 27 巻 1 号 p. 31-37
詳細
1958 年 27 巻 1 号 p. 31-37
U-SCOPE is a new contrivance built on radar principle for rapid detection of radioactive sources in field survey.
A scanning collimator, the axis of which is kept either vertically or horizontally, revolves arround a set cylindrical scintillation crystal with a constant angular velocity of 60°/s. Pulses from the scintillator caused by gamma rays coming from the direction to which the collimator window is faced are picked up and the intensity of radiation as well as the direction of the sources located arround the observer are simultaneously indicated on a screen without any other auxilliary instrument such as scalar, pulse recorder etc.
There are two modes of observation, Type A and Type B, with the U-Scope. Type A has the advantage in measuring weak fields in that every pulse is transformed into a video signal and put into the cathode of the radar tube so that a brilliant dot appears on the survey vector sweeping along the radius at that instant. The intensity of radiation is directly obtained from the density of brilliant dots within the segments bordered by rings and radial vectors forming a polar coordinate system. The area of each segment is swept out in 0.1 second. Hence, the number of dots found within the segment multiplied by 10 gives the counting rate per second. With Type B, which is suited to measuring strong fields, the UScope serves as an automatic tracer of curves denoting the azimuthal intensity distribution of radioactivity.
