Alpha Gridded Ionization Chamber Spectrometer System Developed

The article introduces the parallel plate grid ionization chamber system which is used to measure the Alpha radioactivity. It is composed of three parts: a grid ionization chamber, vacuum system and electronics system. As the crust of the chamber which is made up of stainless steel is cylinder. The pole boards of grid ionization chamber are circular. Argon-methane mixture gas is selected as working gas, it is flowing when the system is working at flow rate of 50ml/h. The high voltage polarities are negative for both cathode and grid.By the test of the chamber, we get its optimal parameter, the space between anode and grid is 20mm, the high voltage for cathode is -2700V and -500V for grid. When the pressure range from 0.10MPa to 0.15MPa, the best energy resolution can reach 25KeV (for Pu-239α-source), the maximum sample diameter is 20mm, the background is 4 counts per hour at energy range of 4Mev and 6Mev, and the detection efficiency approaches to 50%.The grid ionization chamber can be used to measure the energy of nuclide and analyze the structure, and then identify both the nuclide and the content.