The kl and kla Monte Carlo codes



Intro

This is an attempt to document how the kl_sd/kla Monte Carlo codes to 'model' feeding and decay of superdeformed bands work. Both the codes and feeding/decay theories are complicated - so some of the explanations are a bit terse.

The kl_sd/kla Monte Carlo codes were ported from VMS (yes, I have a dark past on the platform... didn't know better at the time) so some things don't quite work properly yet. The code should be refined as time goes on.


Theory of feeding and decay of  SD bands

...to be written.

However, here is an old postscript file that explains some of the inner workings of the Monte Carlo process. It is a bit out of data; but most of the formulas still hold....


How to use the kl Monte Carlo code

The first thing to do is to get and modify a script file to run the program. Currently, a script file looks like
#
# $Id: go_kl_sd_feed,v 1.1 1998/06/19 20:27:56 tl Exp tl $
#
rm -f do.tmp toplist.dat *.TOP *.top
#
kl_sd <<+
80,192                ! z,a of nucleus
n
1                     ! modulus for normal writeout
50000                 ! # number of cascades
0.0,0.0               ! primary cut off energies
total_entry.mascii
EIND162
1                     ! # times to smooth the entry dist.
10.4,10.4             ! n&sd entry spins
8.0 ,8.0              ! n&sd exit  spins
1.2,0.8               ! pairing term
24.0,24.0             ! level dens par
1                     ! level density type
0.01,0.01             ! minimum rho cascade cut off condition
400.0,1900.0          ! mean entry quadrupole moment
400.0,1900.0          ! mean exit  quadrupole moment
0.085,0.085           ! rotational damping width (sigma)
0.2,0.2               ! __ associated cut off energies
hg192_n_gdr.dat
hg192_sd_gdr_wide.dat
hg192_nd_yrast.dat
hg192_sd_yrast.dat
hg192_j1_nd.dat
3                     ! smooth
hg192_j1_sd.dat
3                     ! smooth
88.75,121.55          ! rigid body moment of inertias
10   ,10              ! % mean energy jitter
hg192_bsd.dat
0.5                   ! minimum barrier hight
homg.dat
0,5.0                 ! e1 precalc range u
0,2.0                 ! e2 precalc range mean e
do.tmp
decay_out.dat
+
#
The kl_sd program will ask questions, which are answered in the script file via the
<<+
.
.
.
+
redirection.

In this case the starting entry distribution is read from the file "total_entry.mascii" which is an ascii matrix. The file contains lines of the form "k h count" as:

    8    4      2
    9    2      2
    9    3     26
    9    4     18
    9    5     21
   10    2      3
   10    3     35
   10    4     25
.
.
.
   51   26     17
   51   27      2
   52   23      1
   52   24      6
   52   27      4
   53   27      5
   54   27      4
   54   28      4
   55   27      1
   55   28      5
(for sparse data, this type of ascii matrix is advantageous since it will work on all platforms and both in C and Fortran). The "EIND162" is not used, ignore it. After the entry distribution follows a number of parameter pairs for the ND and SD wells, respectively.

Some of the inputs at the end are 'spectra' of moments of inertias etc. They all have a very simple (and platform independent) format. E.g., the "hg192_j1_nd.dat" file looks like this:

 0 60.98
33 60.98
36 75.5
90 75.5
which gives the moment of inertia at 4 spins (0, 33, 36, 90). The kl_sd program will linearly interpolate between the data-points given. In addition, when it makes sense, after some of these files there is an option to smooth the data a given number of times after the linear interpolation.

Finally, the last line is the name of the event-by-event data file where the gamma cascades are stored: "do.tmp". (ignore the "decay_out.dat" line, it's not used in this case). When you run the program you should see an output that looks something like this. (it's a bit messy to read because of some formatting problems). A number of spectra are written out:

gdr_n.top                                                   
gdr_s.top                                                   
kl_n_yrast.top                                              
kl_s_yrast.top                                              
kl_yrast.top                                                
j1_nd.top                                                   
j1_sd.top                                                   
eg_nd.top                                                   
eg_sd.top                                                   
kl_vn.top                                                   
kl_vs.top                                                   
kl_bsd.top                                                  
kl_homega.top                                               
kl_yrast_comb.top  
Most are the 'completed' spectra from .dat files and can be displayed directly by the 'xmgr' plotting program. The analysis of the gamma cascades in the "do.tmp" file is explained in the following section.


How to use the kla analysis program

This section explains how the gamma cascades in the output file from kl_sd are analyzed with the kla program

Here is an example of a script file that will analyze such a file:

#
# $Id: go_kla,v 1.2 1998/06/12 16:41:44 tl Exp tl $
#
rm -f TOPLIST.DAT KLA_CASCADES.DAT
#
kla <<+
0,100                ! entry point spin window range
0,100                ! entry point u    window range
all                  !specify starting states- nd,sd or all
all                  !specify end point
any
y
5000              ! # cascades to analyze
/home/tl/d6/kl/hg192_se.dat
80                   ! z
0.5                  ! tf foil start
6.6                  ! tf foil thickness
.00                  ! b0 - kill
.21                  ! g factor
.340,-.076           ! a2,a4 for e2
-.222,+.446,-.217    ! a2(-1),a2(0),a2(+1) for e1
1.9,0.0              ! u0 nd & sd; orig. u0_nd is 2.1
0.0,0.0              ! ust


25,50                ! vector selection
do.tmp
+

exit
The first five lines specifies how the cascades are selected -- see the log file for details. The next 'y' asks the program to write "a sequence of cascades to a file". Then follows the maximum number of cascades the program should analyze.

The "/home/tl/d6/kl/hg192_se.dat" file contains the v/c vs time information:

             v/c    t[ps]      x        E     Se     Sn   Stot
    0.0180686601   0.0002  0.001  29.1882  10.39   1.46  11.85
    0.0180356726   0.0023  0.010  29.0817  10.36   1.46  11.82
    0.0179990456   0.0047  0.020  28.9636  10.32   1.46  11.79
    0.0179624427   0.0070  0.030  28.8459  10.29   1.47  11.76
    0.0179258622   0.0094  0.040  28.7286  10.25   1.47  11.72
    0.0178893041   0.0117  0.050  28.6115  10.22   1.48  11.69
    0.0178527739   0.0141  0.060  28.4947  10.18   1.48  11.66
    0.0178162660   0.0165  0.070  28.3783  10.15   1.48  11.63
    0.0177797824   0.0188  0.080  28.2622  10.11   1.49  11.60
.
.
.
    0.0032493740   0.7945  4.225   0.9300   1.05   4.69   5.74
    0.0029934668   0.8084  4.250   0.7872   0.97   4.72   5.69
    0.0027167955   0.8236  4.275   0.6461   0.88   4.73   5.61
    0.0024141751   0.8406  4.300   0.5076   0.78   4.70   5.48
    0.0020779362   0.8600  4.325   0.3730   0.67   4.62   5.29
    0.0016958759   0.8831  4.350   0.2448   0.55   4.42   4.97
    0.0012464433   0.9130  4.375   0.1280   0.40   3.97   4.37
    0.0006851506   0.9599  4.400   0.0343   0.22   2.84   3.06
     0             0.9600  4.400    0        0      0      0

for the ions so that it can calculate how the gamma spectra looks like in the lab taking into account: When you run the program you should see an output that looks something like this. A large number of spectra are written out, in this example:
a0.top                   exit_prob_e.top          mean_u_vs_i.top
alleg.top                exit_prob_i.top          mtot.top
alleg_nd.top             exit_prob_u.top          mult_di.top
alleg_sd.top             exit_t.top               mult_e2.top
av_decay_path.top        exit_t_short.top         mult_st.top
composite.top            i_in_vs_i_ex.top         no_di_vs_x.top
composite_nd.top         j1_nd.top                no_e1_vs_x.top
composite_sd.top         j1_sd.top                no_e2_vs_x.top
d1_tab.top               kl_yrast_comb.top        pos_tab.top
decay_type.top           kla_entry_points.top     ratio.top
decay_vs_gno.top         kla_exit_points.top      sig_av_dec_path.top
decaytime_all.top        m_del_vs_egam.top        spin_vs_x.top
decaytime_dipoles.top    m_di_vs_x.top            st_all.top
decaytime_e2.top         m_e1_vs_x.top            st_nd.top
decaytime_stat.top       m_e2_vs_x.top            st_sd.top
di_all.top               m_ex_t_vs_mult.top       to_grass_decay_pos.top
di_nd.top                me_di_vs_egam.top        tot_qc.top
di_sd.top                me_di_vs_spin.top        tot_qc_32.top
disc_feed.top            me_di_vs_step.top        u_in_vs_i_ex.top
e2_all.top               me_di_vs_u.top           vc_tab.top
e2_nd.top                mean_a2.top              vc_vs_e_di.top
e2_sd.top                mean_a4.top              vc_vs_e_e2.top
e_in_vs_i_ex.top         mean_di_vs_i.top         vc_vs_e_stat.top
e_tab.top                mean_e2_vs_ex_i.top      vector.top
e_theta_1.top            mean_e2_vs_i.top         vector_nd.top
e_theta_2.top            mean_e2_vs_i_nd.top      vector_sd.top
eg_nd.top                mean_e2_vs_i_sd.top      vn.top
eg_sd.top                mean_e2_vs_step.top      vs.top
entry_prob_e.top         mean_st_vs_i.top         wn.top
entry_prob_i.top         mean_time_vs_i.top       ws.top
entry_prob_u.top         mean_time_vs_u.top
The meaning of the spectra are explained (in terse terms) in the log file in lines like:
 spectrum..: e_in_vs_i_ex.top                                            
 _contains.: av entry e vs exit i
and most of the spectra can be viewed by the 'xmgr' plotting program.


FAQ


Misc

...to be written.


Torben@anl.gov