Search file

A search_file format is defined as follows:

(2*string, 2*integer: free format)
input_file, output_file, nvariables, ndatasets

input_file: name of file (in single quotes) with regular FRESCOX input
output_file: name of file for the final FRESCOX output
nvariables: number of search variables
ndatasets: number of experimental data sets.

Repeated nvariables times, a namelist with some of the following variables:

namelist  &variable:
name,kind,step,valmin,valmax, kp,pline,col,potential,nopot,
dataset,datanorm,dataEshift,reffile, nafrac,afrac,
energy, damp, jtot,par,channel,width,rwa,B, leff,
pline2,col2,ratio2

name is name of variable (up to 10 characters),
kind: 0=ignore, 1=potential, 2=afrac, 3=R-matrix energy,
4=R-mat partial width, 5=dataset normalisation
step: step size for finding derivatives etc, zero for fixed. (default 0.01)
valmin: strict lower bound (if non-zero),
valmax: strict upper bound (if non-zero),
null: (default -124578) `undefined' value,

kind=1: Variable potential parameter:
kp: number of potential as in &pot namelist,
pline: order of which &pot namelist within potential definition,
col: number within namelist: selecting P0–P7 ,
potential: value of this potential parameter (default null: use input_file)
pline2,col2: if both assigned, then potential parameter at line pline2 and index col2 is automatically set to a value of ratio2 times this parameter's value.

kind=2: Variable spectroscopic amplitude:
nafrac: order number of &cfp namelist in input_file
afrac: spectroscopic amplitude A (default null: use input_file)

kind=3: Variable energy of R-matrix term:
term: term number (default 1)
jtot: J value for additional R-matrix term
par: parity (+1 or –1)
energy: energy (cm MeV in entrance channel) of additional R-matrix term (default 0)
damp: energy (cm MeV in entrance channel) of imaginary width of this R-matrix term (default 0). The actual imaginary part is damp/2
nopot: Disable potential & Buttle correction for this J/pi set (logical T or F, default F)

kind=4: Variable partial width of R-matrix term:
channel: channel number (in order generated by FRESCOX)
term: term number (default 1)
rwa: the width is reduced width amplitude $\gamma$ , else $\Gamma=2\gamma^2 P$ . (default T)
B: the boundary condition B. (Default: from BNDX).
width: width for this channel (MeV $^{1/2}$ if rwa or energy subthreshold, else MeV(cm)) (default 0)

kind=5: Variable dataset normalisation:
dataset(1:2): index (or, first and last, inclusive) of which dataset (1 to ndatasets) (default 1), or
reffile: filename of dataset. If has a `*', renorm all sets with names matching up to that character,
datanorm: search on absolute normalisation factor of this dataset and its error (default: 1.0)

kind=6: Variable dataset energy shift:
dataset(1:2): index (or, first and last, inclusive) of which dataset (1 to ndatasets) (default 1), or
reffile: filename of dataset. If has a `*', shift all sets with names matching up to that character,
dataEshift: search on absolute energy incremental shift of this dataset (default: 0.0)

kind=7: Variable damping width of R-matrix term:
term: term (default 1). For the real energy there should be a kind=3 variable with the same term.
damp: Imaginary width (cm MeV in entrance channel) of this R-matrix term (default 0).
When energy is set, use the (real) leff to rescale the damping width according to energy above threshold energy by the penetrability ratio $P_{\rm leff}(E - {\tt energy})/P_{\rm leff}(e_{\rm pole} - {\tt energy})$ , with elastic Coulomb. If not set, use constant damping widths as 2*imaginary parts of the pole energies.
The damp variable in kind=3 is fixed, but those in kind=7 can be varied in searches.

Repeated ndatasets times, namelist with some of the following variables, then the corresponding data:

namelist \&data:
type,data_file,points,delta,xmin,lab,energy,angle,
idir,iscale,abserr,ic,ia,k,q,jtot,par,channel,value,error,leg,ib,
pel,exl,labe,lin,lex,term

type (default 0)
= –3 Legendre coefficient for input energy and fixed order leg
= –2 Legendre coefficient (integer order leg) for input energy: double distribution
= –1 Legendre coefficient for varying integer order leg, for fixed energy
= 0 angular distribution for fixed energy
= 1 excitation and angular cross section double distributions
= 2 excitation cross section for fixed angle
= 3 excitation total cross section. Also: ic=0: ia=0 is total reaction cross section; ia=1 is total fusion cross section; 1 $<$ ia $<$ NFUS+1 are fusion from potential KFUS (in &Fresco namelist) for inelastic state ia–1.
= 4 excitation phase shift for fixed partial wave
= 5 desired factor for bound state search (binding energy or potential scale according to ISC).
= 6 specific experimental constraint on a search parameter par, to be value with error error (abserr=T or F).
= 7 specific constraint on energy of R-matrix pole term in the Brune basis to be value with error error (abserr=T or F).
= 8 specific constraint on total formal width of R-matrix pole term in the Brune basis to be value with error error (abserr=T or F).

data_file: name of data file with data, ` $=$ ' for search_file, ` $<$ ' for stdin (default ` $=$ ')
points: number of data points (default: keep reading as many as possible),
delta: if non-zero, construct linear x-scale from xmin in steps of delta, (default 0)
lab: T for lab angles and cross sections (default F for cm frame).
Aflip: T to change cm calculated angles to $180-\theta$ (default F).
energy: lab energy for this type=0 dataset (default: use ELAB(1) from &Fresco namelist)
pel,exl,labe,lin,lex: specify input channels for this data set.

idir (default 0)
=-1 cross-section data are given as astrophysical S-factors, but will be converted to absolute,
= 0 cross-section data are given in absolute units,
= 1 cross-section data are ratio to Rutherford
= 2 cross sections are given in absolute units but will be converted to ratio to rutherford.

iscale (default 2)
= -1 dimensionless (eg ratio to rutherford if idir=1),
= 0 absolute cross-section units are fermi-squared/sr.
= 1 absolute scale is barn/sr
= 2 absolute scale is mb/sr
= 3 absolute scale is micro-b/sr

abserr: T or F for absolute error (default F)
ic: partition number of cross section channel (index of Cards 6) (default 1)
ia: excitation pair number of cross section (index of Cards 7) (default 1)
k: tensor rank of cross section (0, 1, 2,..) (default 0).
q: index for tensor $T_{kq}$ of cross section (0, 1, 2,..) (default 0). $T_{00}$ = angular distribution $\sigma(\theta)$ .
jtot: The J value (as on Card 2) for phase shift
par: The parity (–1 or +1) for phase shift, for type=4
par or number of search parameter, for type=6.
channel: Channel number of entrance channel in coupled channels set (default 1), for phase shift
value: Value of search parameter, for type=6
error: Error in value of search parameter, for type=6

ib: if 0 $<$ ib $<$ ia, then ib is final state of gamma decay. (default 0)
If this is given for data type=0,1,2, then the ia is the initial state, and all angles are the gamma detection angles, and cross sections are integrated over all ejectile particle angles. Need to set dgam=1, pp=3, kqmax $\geq 2\times$ spin of state ia, thmin=0 and thmax=180 degrees.
`

Data input (free format):
if type=1 or –2, read: energy, angle, value, error
if type=5, read: kn, target, error
otherwise:
if delta $\ne$ 0, read: value, error
if delta=0, read: x, value, error

where x is angle for type=0, is leg for type=–1 or –2, and lab energy for type=–3, 2, 3 and 4.