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GiBUU

# Jobcard switches for the Deuterium target

In section 8.4.1 of Oliver Buss' thesis there are details given on the GiBUU deuterium implementation. The aim of this wiki page is to outline jobcard switches, which are necessary to make use of this implementation.

First the target has to be adjusted to Deuterium:

$target target_Z=1 target_A=2 fermimotion=.true.$end


To distribute the nucleons in position and momentum space we can choose between two different wave function models:

$deuteriumFermi waveFunction_switch=2 ! 1=Bonn ! 2=Argonne$end


Next, we need to define a potential to bind the two nucleons. For this we can't use a mean field, because Deuterium represents a too small system. Instead we use a real two-body potential. Using the parallel ensemble technique, the potential V for each nucleon in the jth ensemble is given by $$V=V_\text{2-body}(r_{1,j}-r_{2,j})$$ where $$r_{i,j}$$ is the position of the ith nucleon in the jth ensemble. For the full ensemble method, a Deuterium potential is not yet properly implemented. So we choose for the general input and the propagation routines the following switches:

$input delta_T = 0.025 ! small time step sizes since the two-body potential is stiff and therefore the propagation is sensitive to too large time steps fullensemble=.false. ! => use parallel ensemble technique freezeRealParticles=.false. length_perturbative=1 ! We don't use perturbative particles, see comments below ...$end

$initDensity densitySwitch=1 splineExtraPolation=.true. !Switch for linear spline extrapolation for dynamically calculated density: Extrapolates density between gridPoints(1)=100 gridPoints(2)=100 gridPoints(3)=100 gridSize(1)=8. gridSize(2)=8. gridSize(3)=8.$end

$propagation delta_P=0.01 ! Delta Momentum for derivatives DerivativeType=2 ! 1=first order Range-Kutta, 2=second order Range-Kutta predictorCorrector=.true. ! Whether to use a predictor/corrector algorithm to do the propagation$end

$baryonPotential EQS_Type=7 ! => Two body potential for deuterium DeltaPot=1 ! Switch for potential of spin=3/2 resonances ! 1=nucleon (spin=1/2) potential times 3/5 [according to ericson/Weise book] ! 2= 100 MeV *rho/rhoNull symmetriePotFlag=.false. ! Switch for the assymetry term in the nucleon potential$end

$Yukawa yukawaFlag=.false. !decides whether Yukawa is switched off(.false.) or on (.true.)$end


Oliver prefers not to use perturbative particles with Deuterium, since there is no unperturbed nucleus left if there is a nuclear reaction in deuterium. So he chooses

$low_photo_induced ... realRun=.true. ! => reaction products are set into real particle vector$end