Characteristics of ionization chambers for intense pulsed x-rays and Co-60 γ-rays, 4

Pulse figures obtained with a aluminium wall ionization chamber under the exposure to intense pulsed X-rays were measured. Gases enclosed in the chamber were krypton and air. Observed pulse figures showed peculiar characteristics of voltage dependency. For increasing of applied voltage, the characteristics were as follows; (1) Krypton- Sharp peak appeared at the front of pulse at low applied voltage and then became small at higher voltage while drifting to the end of pulse. Pulse height showed maximum value at a certain voltage and showed lower value at the higher voltage, showing. the saturation characteristic or minimum value. Pulse figure obtained in the region of saturation or minimum value of pulse height was similar closely to the shape of incident electron beam. (2) Air-Pulse height increased monotonically with increase of applied voltage at the pressure of 1 atm. but it showed the saturation characteristic at low pressure. Pulse shape obtained in the region of saturation was similar closely to the shape of incident electron beam. (author)