Radiation detection apparatus and radiation detecton method

A radiation detection apparatus comprising:

• a wavelength selecting unit that allows light having a wavelength selected as a wavelength when a light emission of gas excited by an alpha ray is occurred to pass through the wavelength selecting unit;
• a first polarization selecting unit that receives the light from the wavelength selecting unit, selects a polarization direction, and allows a light of the selected polarization directions to pass through the first polarization selecting unit;
• an optical system that forms an image of the light passed through the wavelength selecting unit and the first polarization selecting unit;
• a photon detecting unit that observes the image formed by the optical system, and detects the photon in whole range of the image;
• and
• a counting unit that counts the photon detected by the photon detecting unit, identifies the photon derived from the light emission of gas excited by the alpha ray based on a value obtained from a result of counting the detected photon, counts the identified photon, and calculates the number of the alpha ray based on a result of counting the identified photon.