Evaluation of a new ionisation chamber fabricated with carbon nanotubes.

Ionisation chambers are the most practical and important radiation measurement devices due to their high sensitivity and relatively constant response with wide range of applied potential. In this work, a new plane-parallel ionisation chamber is proposed using carbon nanotubes as sensing electrodes. Some characteristics of the new chamber such as cable effect, leakage current and reproducibility are investigated. The polarisation effects, besides voltage effect and linearity are also verified. All tests are performed using a 60Co gamma radiation source. The obtained results are compared with that of a standard ionisation chamber (PTW Roos W34001 plane-parallel ion chamber) and international code of practice on dosimetry (i.e. IAEA TRS No. 381).