IMPACT IONIZATION IN LOWER ATMOSPHERE OF VENUS

The high energy particles (electrons and protons) passing through the lower atmosphere of Venus are attenuated and produce ionization of atm ospheric constituents. In this paper, the loss of energy of electrons (10(5) < E < 10(8) eV), protons (10(7) < E <10(12) eV), and Bremsstrah lung radiation due to electrons of energy 10(4) < E < 10(8) eV have be en computed. The results are used to study the impact and Bremsstrahlu ng photoionization in lower ionosphere of Venus. The production rate d ue to the attenuation of energetic particles has been evaluated. It is shown that the production rate due to non-relativistic protons is dom inating above 100 km, whereas below this height extreme relativistic p rotons are effective and produce a peak at the height of 65 km.