Laser Power Balance for Effective Multi-Step Photoionization of Degenerate Atoms.

Abstract

Optimization of laser power balance is studied numerically for effective multi-step photoionization of degenerate atoms. To date, a large number of similar studies have been executed for simple nondegenerate atoms and, therefore, the emphasis in this study is placed on investigating the role of the level degeneracy. It is concluded that a monotonically increasing ]-value in the excitation ladder of levels is preferable, which is followed by some variations thereof. It should also be noted that a reasonably high ionization rate is attainable, in any case, provided that the Rabi-frequencies are optimized at the expense of the sizable laser powers required. The computer code employed here, which deals with the population evolution among numerous magnetic sublevels, has been tested against experiments in advance of the above numerical study.

Modelling and analysis of nucleon emission from deuteron-induced reactions at incident energies up to 100 MeV

“…is considered as a promising reaction to generate intensive neutron beams. Fig.1 shows experimental thick target neutron yields (TTNYs) from (p,xn) and (d,xn) reactions on 9 Be [1,2]. This figure shows some advantages of a (d,xn) neutron source over a widely-used (p,xn) neutron source.…”

“…For the ground and the first excited states of 13 N, we adopt the same F i as the ones for the corresponding states of 13 C derived in Ref. [9]. For the second and the third excited state of 13 N, we fix each F i so as that …”

“…Input parameters used in DWUCK4 calculations are listed in Table 1. These parameters are based on our previous work [9]. Table 1.…”

“…Finally, preequilibrium and evaporation components are estimated using the CCONE code [12], which was successfully applied to neutron nuclear data evaluation for the latest version of Japanese Evaluated Nuclear Data Library (JENDL-4.0) [13]. In our previous works, the code system has been successfully applied to systematic analyses of double-differential cross sections (DDXs) of (d,xp) reactions for 12 C, 27 Al, and 58 Ni at incident energies up to 100 MeV [7][8][9]. The calculation is in good agreement with the experimental data.…”

“…Therefore, we have so far developed a computational code system dedicated to deuteron-induced reactions in combination with some theoretical models [6][7][8][9]. Elastic breakup and stripping reactions to continuum are calculated using the codes based on the ContinuumDiscretized Coupled-Channels method (CDCC) [10] and the Glauber model [6], respectively.…”