coulomb excitation data analysis codes; gosia 2007 - Physics and ...

5.12 OP,INTG (INTEGRATE)This command produces the most accurate calculation of the yields of deexcitation γ-rays following Coulombexcitation to be used for realistic comparison with experimental data. This option includes integration oversolid angle of the particle detectors, energy loss in the target as well as full correction for the recoil velocityof the deexciting nucleus and the deorientation effect.OP,INTG comprises two distinct stages. The first stage calculates the yields of deexcitation γ-raysintegrated over azimuthal angle φ for each energy and scattering angle meshpoint. This calculation of themeshpoint yields should be repeated for each experiment according to the order that the experiments appearin the EXPT input. GOSIA stores the calculated meshpoint yields as internal files. The second stage usesthe data stored in these internal files to integrate over bombarding energy and the range of scattering anglessubtended by the particle detectors which is performed by interpolating between the γ yields calculated ateach meshpoint. It is permitted to integrate over any arbitrary (θ, φ) shape for the particle detector includingthe case of several (≤ 4) φ ranges for each θ value. An option is included to simplify integration over circulardetectors because of the frequent use of such a geometry. The input for the circular detector is a slightlymodified subset of the normal input.The full input to OP,INTG is described below followed by the input for the circular detector option.Since the input to OP,INTG is long, a summary of the input is given at the end of this section to serve as aquick reference. Section 7.4.4 shows the correct location of OP,INTG in the input stream.5.12.1 NORMAL INPUT TO OP,INTGThe input sequence is as follows:OP,INTGNE,± NT,E min ,E max ,θ min ,θ max–––––––––––––––––––where:NENTThe total number of energy meshpoints at which full Coulomb excitation calculations will beperformed (NE ≤ 20).The total number of θ meshpoints at which the full Coulomb excitation calculations will be performed,(NT ≤ 11). Negative value of NT specifies that the ∆φ data specifying the shape of thedetector will be entered by the user to improve the accuracy for complicated θ, φ, shapes. ( see below)E min , E max The minimum and maximum bombarding energies (in MeV) between which the integrationis to be performed.θ min , θ max The minimum and maximum angles (in degrees) between which the integration is to beperformed. Note, θ angles are always positive and correspond to laboratory scattering angles of thedetected particle, that is, the angle of the scattered projectile if it is detected and the angle of therecoiling target nucleus if it is detected. The above input string is modified if the circular detector flagCRD in CONT is activated for this experiment, as described later.–––––––––––––––––––-E 1 , E 2 ,...E NE Energy meshpoints at which the exact Coulomb excitation calculations are performed(MeV). These must exceed or at least equal the range over which the integration is to be performedto obtain reliable Lagrange interpolation.79