Time-reversal Studies in Photorecombination and Photoionization Experiments with Ion Beams

Abstract

Abstract. The principle of detailed balance relates the cross sections σ PR for photorecombination (PR) and σ PI for photoionization (PI) of ions on a state-to-state level. Measuring one or the other of the two cross sections provides direct information about the time-reversed process. Measurements carried out at the Advanced Light Source, Berkeley, for PI of C 2· and Sc 2· are compared with experimental results from the heavy-ion storage ring TSR, Heidelberg, on PR of C 3· and Sc 3· , respectively. From that comparison, state selective cross sections can be inferred both for PR and PI. Both experimental approaches provide possibilities for high-resolution spectroscopy of multiply excited states.

Fusion-Related Ionization and Recombination Data for Tungsten Ions in Low to Moderately High Charge States

“…Absolute cross sections with high energy resolution were determined over wide energy ranges. The idea for the measurements with tungsten ions was to exploit, firstly, the time-reversal relation between recombination and photoionization [109][110][111][112][113][114][115][116][117][118][119][120], and secondly, to contribute to the exploration of the electronic structure of tungsten ions. It is known that the plasma density in a fusion device is low so that absorption of high-energy photons is unlikely.…”

Photoionization of N3 +and Ar8 +in an electron beam ion trap by synchrotron radiation

“…They also offer the possibility of performing systematic studies on electron-electron correlation along isoelectronic and isonuclear sequences, a tool capable of providing deep insights into many-body quantum mechanics. Since direct PI measurements are largely missing for HCIs the study of the time-reversed process to PI, namely photorecombination, using ion storage ring [14][15][16][17] and electron beam ion trap (EBIT) [18][19][20][21][22] techniques has given access to valuable data for benchmarking theory through the principle of detailed balance. However, these methods only gave a partial view of PI, and direct measurements are of great importance.…”