Excitation Of Atomic Hydrogen To The N=2 States By 15-200-keV Protons

Cross sections for the process H+ + H H+ + H* (n=2) are determined from the energy-loss spectra of 15-200-keV protons. After normalization at 200 keV to the Born approximation, the maximum value (1.07 x 10-16 cm2 at 60 keV) lies below close-coupling calculations and above Glauber-approximation calculations. The agreement with low-energy (5-30-keV) data of others is very good. © 1975 The American Physical Society

Angular Differential and Total Cross Sections for the Excitation of Atomic Hydrogen to Its n=2 State by Helium Ions

Differential cross sections for 15-100 keV He+ excitation of atomic hydrogen to its n=2 level have been determined for c.m. angles from 0 to 8 mrad. The differential cross sections are obtained from an analysis of the angular distribution of the scattered ions which have lost an energy corresponding to the excitation of the target to its n=2 level. The shape of the differential cross section changes rapidly with increasing incident energy. At 15 keV, the differential cross section falls off by a factor of 5 in 6 mrad. At 100 keV, the differential cross section decreases by nearly six orders of magnitude in the same angular range. The higher-energy results are in fair agreement with a recent symmetrized first-order Glauber approximation calculation of the process. Total cross section results are given for the same process in the 15-200 keV range

Angular Differential and Total Cross Sections for the Excitation of Atomic Hydrogen to Its n=2 Level by 25-150-kev Hydrogen Molecular Ions

Experimentally and theoretically determined differential and total cross sections are reported for excitation of atomic hydrogen to its n=2 level by 25-150-keV hydrogen molecular ions. The differential cross sections decrease 3-4 orders of magnitude over the measured center-of-mass scattering-angular range from 0 to 4.5 mrad. The results of a first Born approximation and two other theoretical calculations based upon the Glauber approximation are presented and compared with the experimental results. Both calculations based on the Glauber approximation agree fairly well with the experimental results. The Born approximation agrees moderately well with the experimental results at the very small scattering angles but is well below the experimental results at the larger scattering angles. None of the theoretical calculations presented agree well with the total cross section. However, the results for the total cross section of the two calculations based on the Glauber approximation agree with the experimental results in curve shape better than the Born-approximation results