Free-ion yield for tetramethylsilane and tetramethylgermanium

Free-ion yields from /sup 207/Bi conversion electrons are measured as a function of applied electric field in an ionization chamber filler with tetramethylsilane (TMS) or tetramethylgermanium (TMG), which are purified by simple methods. The mean thermalization length of electrons liberated in the liquid is calculated by fitting a Gaussian form for the distribution function. The total free-ion yield and thermalization length in TMS and TMG are obtained. They are 3.1+or-0.3, 3.5+or-0.2 and 1.91+or-12 AA, 173+or-16 AA, respectively, including the impurity effect in liquid.<
>