On the basis of measurements of double differential cross sections for (n,α) reactions in 5-7 MeV neutron energy region using gridded ionization chamber (GIC), we constructed a new GIC which, compared with the old ones, can bear higher pressure and makes it possible to measure (n,p) reactions up to 6 MeV and (n,xα) reactions up to 20 MeV. To test the new chamber, the saturation property for argon and krypton mixed with a few percent CO_2 was studied using ~(241)Am and compound Pu α source and tritium from ~6Li(n_(th),t)~4He, and the two dimensional spectra for ~(241)Am and Pu α source, ~6Li(n_(th),t)~4He and H(n,p) reactions were measured. The measured energy spectra and angular distributions for α and tritium are reasonable, and the derived data for α, proton and tritium in argon and krypton from the measured spectra data were compared with the calculated ones. They are in good agreement. The angular distributions and energy spectra for ~(58)Ni(n,p)~(58)Co reaction at 4.1 MeV neutron energy were m On the basis of measurements of double differential cross sections for (n, α) reactions in 5-7 MeV neutron energy region using gridded ionization chamber (GIC), we constructed a new GIC which, compared with the old ones, can bear higher pressure To test the new chamber, the saturation property for argon and krypton mixed with a few percent CO_2 was studied using (and reacts to 6 MeV and (n, xα) reactions up to 20 MeV. (241) Am and compound Pu α source and tritium from ~ 6Li (n_ (th), t) ~ 4He, and the two dimensional spectra for ~ 241 Am and Pu α source ~ 6Li (n_ (th) The measured energy spectra and angular distributions for α and tritium are reasonable, and the derived data for α, proton and tritium in argon and krypton from the measured spectra data were compared They are in good agreement. The angular distributions and energy spectra for ~ (58) Ni (n, p) ~ (58) Co reaction at 4.1 MeV ne utron energy were m