In this study, the response of a Twin Frisch-grid ionization
chamber (TFGIC) to fission fragments (FFs) was investigated using
finite element and Monte Carlo methods. The entire process of the
fission experiments, including FFs generation, gas ionization,
electron drift and collection, and induced charge signal were well
reproduced. Through data analysis, pulse height spectra from the
anode and grid were transformed into energy and emission-angle
information for the FFs. By means of double energy method, the
pre-neutron emission fission fragment mass and total kinetic energy
(TKE) can be finally determined. Experimental and calculated
data of the mass and TKE distribution are shown in good
agreement.