| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥3,200,000 (Direct Cost: ¥3,200,000)
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| Research Abstract |
An optical pumping atomic magnetometer using potassium vapor cell was constructed and investigated the fundamental characteristics.
The absorption wavelength of the cell with He (He 80kPa) as buffer gas was 770.107 nm, and the absorption line width was 0.02 nm in FWHM. If N2 was added (He 80kPa ; N2 4kPa) as quenching gas, the absorption line width increased to 0.055 nm. The wavelength of pumping beam must be coincide with the absorption wavelength, however, in contrast, the probe beam must be shifted at least 0.1 nm from the absorption center.
At least 10 mW or more of pump beams power are required. Although a signal tend to saturation, more high power pumping laser would improve sensitivity.
When helicity of circular polarized pumping beam was reversed, a rotation direction of linear polarized probe beam was also reversed.
About 50% magnitude of signal can be obtained the cell temperature at 170 C, and begins to be saturated at 190 C. Wide range linearity, from 1 pT to 100 nT, for AC magnetic field at 5 kHz was confirmed without any closed-loop feedback control.
Since the density of beam power was not sufficient to pump the atom if the beam was expanded, the imaging measurement was difficult using low power laser.
In addition, we programmed software to reconstruct the field from probe beam holography.
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