Susumu Okumura, Kazuo Arakawa, Mitsuhiro Fukuda, Yoshiteru Nakamura, Watalu Yokota, Takayuki Ishimoto, Satoshi Kurashima, Ikuo Ishibori, Takayuki Nara, Takashi Agematsu, Tsukasa Nakajima*
Advanced Radiation Technology Center, Japan Atomic Energy Research Institute (JAERI), 1233 Watanuki, akasaki, Gunma 370-1292, Japan,
* Echo Electronics Co., Ltd, 4-8-41 Kashiwa, Siki, Saitama 353-0007, Japan
We have developed a probe of a nuclear magnetic resonance (NMR) magnetometer for measurement of a fluctuation of an AVF cyclotron field. The stability of the magnetic field of the JAERI AVF cyclotron, measured with the NMR probe, was within 1 ´ 10-5. A field-measurement accuracy of the order of 1 ´ 10-6 was achieved using a set of field-compensation coils and optimizing the probe position to obtain enough homogeneity of the magnetic field around the probe for measuring the cyclotron field with a high gradient. To eliminate a major bottleneck in the field measurement inside the cyclotron, the probe was specially produced with the cable shielding against RF noises and proper materials applied.