Y.Kubota, H.Obayashi, A.Miyahara, K.Ohno, K.Nakamura and K.Horii
"Development of Three-Dimensional Compact Magnetic Dosimeter for Environmental Magnetic Field Monitoring"
Date of publication:
three dimensional, magnetic, fluxmeter, sensor, dose, computer, LHD
A computer-driven, three-dimensional magnetic fluxmeter to be used also for magnetic field dosimetry has been developed. A magnetic monitor applicable to this object should be measurable to an absolute value of local magnetic field strength and also be able to record its time integration as a measure of exposed dose to the magnetic field. The present fluxmeter consists of signal amplifires, rectifires, an A/D converter, and a pocket computer(PC). The signal outputs from the sensors are processed with the PC to compose an absolute strength of magnetic flux density and its time-integrated value. The whole system is driven by a battery and is quite compact in size to be used as a handy portable system. Further details of the design, idea, construction, specification, and testing result of the fluxmeter are described. The measurable range are from 0.4G to 20,000G in normal mode and 8mG to 400G in high-sensitivity AC mode, and the sensitivity is well independent of the magnetic field direction. These measured data are displayed in real time on the LCD pannel of the PC and memorized in RAM files. Possible application of the fluxmeter are discussed with special attention to the search of the leakage and/or disturbing error fields around LHD (Large Helical Device) and other magnetic systems, the individual dose control to the workers in strong magnetic fields, and the evaluation of the effects of long irradiation of magnetic fields.