force free spheromak &all equiltype='ffprime' rmax=100. rzero=110.0 ; minor and major radii--here we have A=1.1 modelbnd=1 ; use ishape formulation to get boundary ishape=5 eshape=1.2 xshape=0.7; ishape=5 is dee shape used for low A ; studies. Try ishape = 4 for rounder dee ; with ishape = 4 ; triang. = sin (xshape) ; with ishape = 5 ; triang. = xshape npsi=131 nthet=129 ; mesh size ; acceptable values are ; npsi=19 nthet=17 ; npsi=35 nthet=33 ; npsi=67 nthet=65 ; npsi=131 nthet=129 ;-----pressure profile------------------ modelp=6 ppcoef=-0.0 0.0 nppcoef=2 ; pprime=0 ; ffprime is polynomial--proportional 1-psi_norm below modelf=1 ffpcoef=-150000.0 150000.0 nffp=2 ; ffprime ;---- magnetic field and total current----------- baxis0=1.00e-4 ; set toroidal field ~0 at edge fixcur=.true. totcur=5.0e5 ; specify total current that you want ;--------------------------------------------------------------------- betafix="none" ; do not adjust beta ieqdsk=0 ; there is no initial guess from a dskeqi file iteqmx=2000 toleq=1.e-3 ; convergence criterion--I almost never change this imislo=3 ; sometimes data near axis is garbage--in that case set ; imislo=3 to use extrapolation to axis which should ; clean it up--otherwise set imislo=0 alpsi=-0.99 ; determines the relationship between psic--psi coordinate ; and psiv--psi value=poloidal flux(*2pi) ; alpsi=0 makes psic = sqrt(psiv) normalized to 0-1 ; for alpsi<0 ; psi_norm(i)=(sin(psic(i)*alpsi*pi*0.5))**2/sin(-alpsi*pi*0.5)**2 ; idea for alpsi~-1 is to put lots of surfaces near axis and ; near edge bavq=0. bava=0.0 bavxz=0.0 nbavxz=6 ; relaxation parameters prtgato=.true. ; print out a dskgato file prtbal=.true. ; print out a dskbalnew file &end