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

5.18 OP,POIN (POINT CALCULATION)This option command causes execution of a calculation of the γ-ray yields for one scattering angle andone bombarding energy as specified for each experiment in EXPT. OP,POIN can be used to simulate’corrected’ experimental γ yields. In this mode OP,POIN also generates a ’corrected experimental yieldsfile’ on TAPE4, which can be used subsequently for simulating the real experiments (e.g. to analyze theinfluence of the matrix elements on the supposedly observed yields). Note: when executing OP,POIN oneshould set the experimental yields file selector (NTAP in OP,YIEL input) to 0 - see 5.29. Section 7.4.3 showsthe correct location of OP,POIN in the input stream.The input to OP,POIN is as follows:OP, POINIFL, YLIM IFL =0 specifies the normal calculation, IFL =1 the ’simulation’ calculation. YLIMis redundant if IFL =0,whereasifIFL =1 it specifies that all transitions whose yield divided bythe yield of the normalizing transition (defined in OP,YIEL) exceeds YLIM will be treated as ’experimentallyobservables’ and will be included in the TAPE4 file. OP,POIN will also produce a filecontaining the γ detector efficiency information if OP,RAW was executed and PRT, flag 20 was set to1 (TAPE23). Note that the decay energies in TAPE23 output are Doppler-shifted.Note that OP.POIN evaluates the point γ-ray yield in the laboratory frame for transition I → I f that isdefined by equation 4.16. That is:ZY Point d 2 σ(I → I f )(I → I f )=sin(θ p )dφφ pdΩ γ dΩ p (4.16)pwhere the integrand is given byd 2 σ(I → I f )dΩ p dΩ γ= σ R (θ p ) X R kχ (I,I f ; θ p )P kχ (θ γ )(2 cos χ(φ p − φ γ ) − δ χ0 ) (4.13)kχ≥0Note that Y Point (I → I f ) includes the Rutherford cross section, the sin(θ p ) term, integration over theprojectile φ p angle, the deorientation effect and γ-detector Q K attenuation coefficients.The total number of coincident γ-raysdetectedthenisgivenbyCounts =10 −27 ·∙ Qˆqe¸·∙NAA¸· [ρdx] · Y Point (I → I f ) · ∆θ p · ε p · ε γ · ∆Ω γwhere:Q is the integrated beam charge [C]ˆq the average charges state of the beame the proton charge [1.602 × 10 −19 C]N A Avogadro number [6.022 × 10 23 atoms/mol]A Target mass number [g/mol]ρdx areal target thickness in [g/cm 2 ]Y Point mb(I → I f ) OP.POIN output in [sr·rad ]∆θ p Projectile scattering angle range [rad]ε p particle detection efficiency per unit solid angleε γ γ-ray detector efficiency excluding the geometrical solid angle∆Ω γ geometrical solid angle of the γ-ray detector. Note that usually one only knows the productε γ · ∆Ω γ97