INFRARED RESPONSE OF H-2 TO X-RAYS

The rates of population of the rovibrational levels of H-2 by the impa ct of energetic photoelectrons produced by the absorption of X-rays ar e calculated. Population occurs by excitation of electronically excite d states of H-2 followed by cascading and by direct impact excitation of the lowest vibrational level. The resulting infrared spectra are pr esented. The emission from high vibrational levels is similar to that from ultraviolet pumping. Emission from the v = 1 and 2 vibrational le vels in a gas of low fractional ionization is dominated by direct elec tron impact excitation. The intensity ratio of the S(1)(2-1) and S(1)( 1-0) lines is 0.06 in a gas of low fractional ionization and 0.54 in a gas of high fractional ionization.