Invention Grant
- Patent Title: Magnetic field measurement device
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Application No.: US14905132Application Date: 2013-08-02
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Publication No.: US10162021B2Publication Date: 2018-12-25
- Inventor: Ryuzo Kawabata , Akihiko Kandori , Taro Osabe , Seiichi Suzuki , Yuudai Kamada
- Applicant: Hitachi, Ltd.
- Applicant Address: JP Tokyo
- Assignee: Hitachi, Ltd.
- Current Assignee: Hitachi, Ltd.
- Current Assignee Address: JP Tokyo
- Agency: Mattingly & Malur, PC
- International Application: PCT/JP2013/070958 WO 20130802
- International Announcement: WO2015/015628 WO 20150205
- Main IPC: G01R33/26
- IPC: G01R33/26 ; G01N24/00 ; H01S3/091

Abstract:
A magnetic measurement device has a magnetic sensor including a glass cell having alkali metal gas encapsulated therein that is configured to detect a magnetic field using a magneto-optical characteristic of spin-polarized alkali metal. A laser light source is configured to generate pump light introduced into the magnetic sensor and a coil provided in the same magnetically shielded space as the magnetic sensor is configured to apply a static magnetic field and a RF magnetic field to the magnetic sensor. A signal processor is configured to perform lock-in detection of a light detection signal transmitted through the glass cell of the magnetic sensor, control an intensity of the static magnetic field and a frequency of the RF magnetic field generated by the coil according to a lock-in detection output, and obtain a measurement signal reflecting a magnetic field intensity of an object to be measured in the magnetically shielded space.
Public/Granted literature
- US20160146909A1 MAGNETIC FIELD MEASUREMENT DEVICE Public/Granted day:2016-05-26
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