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RIKEN Accel. Próg. Rep. 24 (1990)

VI-2. Residual Activities in the Ring Cyclotron Facility

S. Fujita, T. Takagi, S. Okamoto, N. Nakanishi,

I. Sakamoto, T. Inamura, and H. Kamitsubo

Residual activities were measured at various points in the Ring Cyclotron Facility.

From June 18 to 24, an experiment was carried out with a ¹⁴N⁷' beam of 135 MeV/u in the experimental vault E4. However, because water leakage was found at a part of north side dee of the AVF cyclotron at the last day of the experi-

Fig. 1. Detection points around the injector AVF cyclotron. Dose rates are indicated in units of nSv/h.

nient, the acceleration chamber was opened. On June 27, residual activities in the AVF cyclotron

Fig. 2. Detection points around RIKEN Ring Cyclotron. EDC, an electrostatic deflection channel; MDC1, a magnetic deflection channel 1; MDC2, a magnetic deflection channel 2; MDP1, a main differential probe 1; MI)P2, a main differential probe 2; MI)P3, a main differential probe 3. Numerals indicated are dose rates in units of //Sv/h.

Fig. 3. Layout of RIKEN Ring Cyclotron facility as of 1990. Monitoring positions are denoted by x. Detection points of residual activity on the beam lines are denoted by alphabets.