Gamma ray and X-rays

The most important types of radioactive particles are alpha particles, beta particles, gamma rays, and X-rays. An alpha particle, which is symbolized as a, is equivalent to a helium nucleus, fHe. Thus, emission of an alpha particle results in a new isotope whose atomic number and atomic mass number are, respectively, 2 and 4 less than that for the unstable parent isotope. 

Emission of an alpha or beta particle often produces an isotope in an unstable, high-energy state. This excess energy is released as a gamma ray, y, or an X-ray. Gamma ray and X-ray emission may also occur without the release of alpha or beta particles. 

Ionizing radiation, such as gamma rays and x-rays, causes complex types of DNA damage that are difficult to repair. Including double-strand and single-strand breaks and cross-links that may lead to leukemia and cancers of many organs. 

If the detector crystal is made of n-type germanium, the outer electrode can be made rather thin. Include a thin aluminium or a beryllium window at the face of the detector, so that low energy electromagnetic radiation will be able to enter the volume of the detector, and you get a gamma ray detector that is good also for soft gamma rays, and X-rays. 

Gamma rays and X-rays are among the most penetrating types of radiations. Gamma rays are produced in the nuclear reactions that take place in nuclear power plants. They were also associated with the nuclear weapons that were detonated in Hiroshima and Nagasaki, Japan. 

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