A measurement of the average energy required to create an ion pair in nitrogen by 250 MeV/amu C⁶⁺ ions

Abstract

With the increasing application of high energy heavy ions in radiobiology, there is a corresponding need to develop reliable techniques of dosimetry. Preliminary measurements of W (the average energy required to create an ion pair), which will facilitate the use of nitrogen-filled ionisation chambers for absolute dosimetry, are reported. A parallel plate ionisation chamber filled with nitrogen and ambient pressure and temperature was used and a value of 36.6+or-0.7 eV was obtained.