PROCESS DETERMINING AVERAGE CHARGE FROM NEUTRONS IN PULSE OF FISSION CHAMBER Russian patent published in 1999 - IPC

FIELD: determination of characteristics of ionization fission chamber. SUBSTANCE: in correspondence with invention chamber 1 including electrode 2 and fission material 3 is connected to outside source of electric voltage and is irradiated with neutron flux. Electric current I_n from neutrons ( switch 4 placed in position " 1 " ) and number of pulses Nd in time interval Δt or pulse counting rate n_d at various levels Vd of discrimination within definite interval inside which absolute value of slope of dependence of Nd or n_d on Vd takes minimum value are measured. At least one measurement is taken in definite subinterval with allowance for discrimination level U_dm at which absolute value of slope of dependence of Nd or n_d on Vd takes minimum value. Measurement results in this subinterval are approximated by means of inverse exponential function f(Vd) depending on the square of argument. Then value Q of average charge is found. Process provides for precision measurement of Q in fission chambers depending on number of measurements in subinterval with reliability of 95%. EFFECT: increased precision and reliability of process. 1 cl, 6 dwg, 5 tbl