Japan Atomic Energy Research Institute

Masaaki Kato

Takashi Arisawa

Yoichiro Maruyama

Akira Ohzu

Koreyuki Shiba

Youji Suzuki

Katsuaki Akaoka

Yoji Suzuki

Tsuyoshi Nakayama

Akira Sugiyama

A remote particle counter comprising a pulsed laser generator, laser light emitting optics, scattered light collecting optics, a high-sensitivity two-dimensional photo detector as a scattered light detecting portion having a fast gating capability such as a CCD camera, and a control and measure system, wherein suspended fine particles forming aerosols in the atmosphere which are far away from the site of laser emission are illuminated with laser light, the resulting backward scattered light from the individual fine particles is detected as image, and the number and size distribution of the suspended fine particles are measured at a remote site.

Remote particle counter for remote measurement of the number and size distribution of suspended fine particles in the atmosphere

The compensation amount of the pressure for keeping the index of refraction of the gas constant is calculated on the basis of the pressures and the temperatures that have been measured at different time. Only the pressure of the gas will be varied in accordance with the calculated compensation value of the pressure, whereby the index of the gas can be maintained constant and the oscillation frequency can be kept constant as the consequence. The pressure corresponding to a desired sweeping oscillation frequency is also calculated using the measured pressures and temperatures. The pressure of the gas is varied on the basis of the result of calculation. Synchronously with the variation of the pressure of the gas, the cavity length and the angle of the frequency selecting element are compensated.

Apparatus and method of stabilizing oscillation frequency for single

The improved metal vapor laser capable of cold operation performs plasma etching on a vaporizing metal within a laser tube in the presence of a reactive gas so that the metal is vaporized at temperatures below its boiling point to effect laser oscillation. The laser can be operated at much lower temperatures than a conventional hot-operating version which produces metal vapors by thermal evaporation; in addition, the laser will experience a smaller heat loss while undergoing limited thermal damage to its structural members; further, laser light can be oscillated to produce high output power and, at the same time, the warmup time can be shortened significantly.

Metal vapor laser capable of cold operation

A method of producing a small expansion of laser light, in a pulse laser apparatus, including producing a small preliminary laser light by pumping a laser medium, and then, after an appropriate time lag, then pumping the preliminary laser medium at a higher intensity than the first pumping, thereby producing a laser light which is smaller in beam expansion than in the case where a preliminary pumping is not performed. The laser light which is smaller in beam expansion is due to the population inversion occurring in a small beam expansion part of pulse laser light obtained by the preliminary pumping.

Method of producing a small beam expansion of laser light

A method is, herein, disclosed for separating a specific isotope from a mixture of isotopes by first irradiating the isotope mixture with a highly monochromatic laser light that resonates only with the energy level of the specific isotope so as to increase its chemical activity and then bombarding said specific isotope with a molecule containing highly reactive atoms so as to form a spatially separated compound rich in the specific isotope.

Growing community of inventors

Ibaraki-ken, Japan

Masaaki Kato