******************************************************************************* 
This is a demo of running crystal diffraction on SHADOW.
*******************************************************************************
System PSLC (vms 4.4)

Username: XRAYOP
Password: 
        Welcome to VAX/VMS Version 4.4
       University of Wisconsin - Madison
         Physical Sciences Laboratory

At 13:30 on 11-Mar, disk drive D13 experienced a destructive hardware
failure.  All files have been restored to their state as of approximately
10:00 on 11-Mar.  Modifications made after that time are irretrievably lost.

INGRES will be upgraded to Version 5.0/03 (vax.vms/02) on Sunday, 15-Mar-1987.

LaTeX classes are being scheduled in the HEP conference room.
Send mail to SYS_KEHRES for more information.

We have TEX_SPELL, a new spelling checker.  See the bulletin for more
information  (enter $ BULLETIN ).

The versatec printer/plotter (lpb0:) is down until further notice.

    Last interactive login on Thursday, 12-MAR-1987 12:06
    Last non-interactive login on Tuesday, 10-MAR-1987 09:37

You are logged into _RTA1:




Defining Logical Names and Environmental Parameters
Graphics device [e.g. TTD3: ] ? : TT:


All logical names and command defined.

Enter $GO to activate SHADOW.

Enter HELPSHA for help.

Type NEWS for recent modifications.: 
$ CREATE/DIR [.XTAL]
$ SD [.XTAL]
$ DIR
%DIRECT-W-NOFILES, no files found
$ !
$ ! BRAGG is the program that generates the crystal parameters in a format
$ ! suitable as input to SHADOW.
$ !
$ ! Let us use the GaAs (111) plane, with incident photon energy of 11160 eV.
$ !
$ BRAGG			
All crystal structures are refered to a cubic unit cell.
Bravais lattice type : 
0	for ZincBlende
1	for Rocksalt
2	for simple FCC
3      for CsCl structure
Then ? 
0
Lattice constant (Angs) ? 
5.65
Index of crystal plane of reflection H,K,L : 
1,1,1
***********************************************************
The ZINCBLENDE structure is defined by atom A located at 
(0,0,0) and atom B at (1/4,1/4,1/4) of the fcc lattice.
***********************************************************
Enter 2-letters (capitalized) atomic symbol for atom A : 
GA
Enter 2-letters (capitalized) atomic symbol for atom B : 
AS
***********************************************************
Atomic scattering factor is defined by fo + f' + if", where
    fo = fo(SIN(theta)/Lambda) is the non-dispersive part
    f', f" (Lambda) are the dispersive part.
***********************************************************
We need fo at 3 different values of SIN(theta)/Lambda, which
should cover the range of interest and center around :
SIN(theta)/Lambda =   0.1532788325282192     ratio.
***********************************************************
Please enter 1) SIN(theta)/Lambda, 2) fo ,
For atom A, first set : 
0.14,27.162				! The International Tables for X-Ray
          , second set : 		! Crystallography lists fo as a
0.15,26.783				! function of SIN(theta)/Lambda for
          , third set : 		! each element and some ions.
0.16,26.406				!
For atom B, first set : 		! Here the user needs to supply fo 
0.14,28.742				! centered around 0.15327..., and 
          , second set : 		! within some limits that SHADOW can
0.15,28.307				! interpolate for fo.
          , third set : 		!
0.16,27.877
***********************************************************
f', f" is furnished from optical constant library within ...
minimum photon energy (eV) : 
11100					
maximum photon energy (eV) : 
11200
energy step (eV) : 
10
Do you want to include crystal absorption [1/0] ? 
1
Temperature factor : 
0.979					! Debye-Waller factor.
Output file name (for SHADOW) : 
GAAS.PAR
Do you want to generate a rocking curve [1/0] ? 
1
... at what energy (eV) ? 
11160
 
So far, we are working with:
Lambda  =    1.110978494623656     Angstroms
Theta (graz)  =    9.804650841199757     degrees
Bragg angle      =    9.807153296220226     degrees
Structure factor  =  (142.6426218594671,11.03752285669588)
Refraction index = 1 - delta - i*beta :
           delta =   7.3270650274570581E-06
            beta =   4.8385681505652676E-07
Absorption coeff =    547.2944878508624     cm-1
 
Real(Ss) :  25.541823566710784 microradians
Real(Sp) :  24.060473952622004 microradians
+/- how many microradians : 
60
How many points : 
200
Do you want to try another energy [1/0] ? 
0
$ DIR

Directory D13:[XRAYOP.XTAL]

GAAS.PAR;1                4  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
ROCK_CURVE.P;1           20  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
ROCK_CURVE.PAR;1          3  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
ROCK_CURVE.S;1           20  12-MAR-1987 12:14  (RWED,RWED,RE,RE)

Total of 4 files, 47 blocks.
$ !
$ ! At the end of the file GAAS.PAR is a table of :
$ ! 	eV	f'(Ga)	f"(Ga)	f'(As)	f"(As)
$ ! from the optical constant library.  The users can edit this part if they 
$ ! have more accurate values, especially near an absorption edge.
$ !
$ T GAAS.PAR
          0   1562378464.990918      3.2620290209213856E-08
         31          33  0.9790000000000000    
(4.000000000000000,-6.8654264713317982E-17)
(4.000000000000000,6.8654264713317982E-17)
(8.4736075498395345E-17,-4.000000000000000)
(8.4736075498395345E-17,4.000000000000000)
  32.67800000000011      -40.80000000000018       10.00000000000364    
  35.35699999999986      -50.74999999999727       24.99999999999272    
         11
  11100.00000000000      -1.895109680624937       3.414937245198015    
 -2.436850441775594      0.5607204097485073    
  11110.00000000000      -1.880106255382257       3.410127243375178    
 -2.449320912049193      0.5598036778163483    
  11120.00000000000      -1.865102830139578       3.405317241552341    
 -2.461791382322792      0.5588869458841894    
  11130.00000000000      -1.850099404896898       3.400507239729505    
 -2.474261852596391      0.5579702139520304    
  11140.00000000000      -1.835095979654219       3.395697237906668    
 -2.486732322869990      0.5570534820198715    
  11150.00000000000      -1.820092554411540       3.390887236083831    
 -2.499202793143589      0.5561367500877125    
  11160.00000000000      -1.805089129168860       3.386077234260994    
 -2.511673263417189      0.5552200181555536    
  11170.00000000000      -1.790085703926181       3.381267232438158    
 -2.524143733690788      0.5543032862233946    
  11180.00000000000      -1.775082278683501       3.376457230615321    
 -2.536614203964387      0.5533865542912357    
  11190.00000000000      -1.760078853440822       3.371647228792484    
 -2.549084674237986      0.5524698223590767    
  11200.00000000000      -1.745075428198142       3.366837226969648    
 -2.561555144511585      0.5515530904269178    
$ !
$ ! ROCK_CURVE.PAR lists the parameters used to generate the rocking
$ ! curve at 11160 eV.
$ !
$ T ROCK_CURVE.PAR
ZincBlende structure :
For atom A, fo + f' + if" =  (24.85407850869210,3.386077234260994)
         B,               =  (25.65378599830614,0.5552200181555536)
Lattice constant =    5.650000000000000     Angstroms
d-spacing        =    3.262029020921386     Angstroms
Photon energy  =    11160.00000000000     eV
Lambda  =    1.110978494623656     Angstroms
Theta (graz)  =    9.804650841199757     degrees
Bragg angle      =    9.807153296220226     degrees
SIN(theta)/Lambda =   0.1532788325282192     ratio.
Refraction index = 1 - delta - i*beta :
           delta =   7.3270650274570581E-06
            beta =   4.8385681505652676E-07
Absorption coeff =    547.2944878508624     cm-1
Temperature factor =   0.9790000000000000    
Structure factor F(000) =  (238.7329504296558,15.76518900966619)
Structure factor F(hkl) =  (142.6426218594671,11.03752285669588)
Real(Ss) :  25.541823566710784 microradians
Real(Sp) :  24.060473952622004 microradians
$ 
$ T ROCK_CURVE.S
-6.0000000000000001E-05  4.4734048523468558E-02
-5.9396984924623116E-05  4.5743273694228367E-02
-5.8793969849246232E-05  4.6788310752051254E-02
:			:
:			:
 5.8793969849246230E-05  4.6607134825068388E-02
 5.9396984924623114E-05  4.5572622137689746E-02
 5.9999999999999999E-05  4.4573179462104158E-02
$ !
$ ! Plot out the rocking curve for S-polarization.
$ !
$ TDTEK
TOP DRAWER (10/10/80) NOW EXECUTING

MOD NOECHO
           1  MOD NOECHO                                                                                
                                                                           
@ROCK_CURVE.S
READING FROM INDIRECT COMMAND FILE: ROCK_CURVE.S                    
           2     -6.0000000000000001E-05  4.4734048523468558E-02
                                                                           
END OF INDIRECT COMMAND FILE
JOIN 1
         202  JOIN 1                                                                                    
                                                                           
END
         203  END                                                                                       
                                                                           
FORTRAN STOP
$ DIR

Directory D13:[XRAYOP.XTAL]

GAAS.PAR;1                4  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
ROCK_CURVE.P;1           20  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
ROCK_CURVE.PAR;1          3  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
ROCK_CURVE.S;1           20  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
SAVE.DAT;1                8  12-MAR-1987 12:20  (RWED,RWED,RE,RE)
TD.FIL;1                  1  12-MAR-1987 12:20  (RWED,RWED,RE,RE)

Total of 6 files, 56 blocks.
 
$ !
$ ! Things seem OK. So we can run SHADOW (finally).
$ ! To check things out, let us use a monochromatic source with only
$ ! vertical divergence.
$ !
$ GO



  :::::::  :::    ::            :::    :::::::        :::::     :::  ::  ::
 ::::::::  :::    ::           ::::    ::::::::      :::::::    :::  ::  ::
:::        :::    ::          ::: :    :::   :::    :::    ::   :::  ::  ::
:::        :::    ::         ::: ::    :::    ::    :::    ::   :::  ::  ::
 :::::::   :::::::::        :::  ::    :::    ::    :::    ::   :::  ::  ::
  :::::::  :::::::::       :::   ::    :::    ::    :::    ::   :::  ::  ::
       ::  :::    ::      :::    ::    :::    ::    :::    ::   :::  ::  ::
      :::  :::    ::     :::     ::    :::   :::    :::   :::   ::: ::: :::
::::::::   :::    ::    :::      ::    ::::::::      :::::::     :::::::::
:::::::    :::    ::   :::       ::    :::::::        :::::       ::: :::




VERSION     86.4                                                19 JAN 1986




Hit <RETURN> when ready: 




                            S H A D O W


Commands Available at this level:

HELP              More informations on the following commands
SOURCE            Generates a source file
TRACE             Starts the tracing of an Optical System from a specified
                  source file
MENU              Begins the process of defining an Optical System
INIT              Defines scratch directories and set default to scratch
EXIT              Returns to DCL




Shadow:: SOURCE


SOURCE selected. Begin procedure.


This procedure generates a SOURCE for SHADOW.
Mode selected [ ? <ret> for HELP ] ? : PROMPT
Call to INPUT




---------------------------------- S H A D O W  ------------------------------- 
Jan 1986                                         F.Cerrina        ECE - UW      

Defining source : 
When prompted for a yes/no answer, you may enter:
for   YES  answer      Y, 1
for   NO   answer      anything else




Do you want a verbose [ 1 ] or terse [ 0 ] output ?
1

------------- SOURCE SPECS ------------------
Options available:
Random in  BOTH REAL and MOMENTUM space      	0
Grid       BOTH      				1
Grid       REAL, random  MOMENTUM              2
Random     REAL,  grid   MOMENTUM      	3
Ellipses in PHASE space, random around each ellipse   4
Ellipses in PHASE space,   grid around each ellipse   5
Source modelling type [ 0-5 ] ? 
0
How many rays [ 1 - 5 000 ] ? 
1000
Seed [ odd, 1000 - 1 000 000 ] ? 
12345

 The source is specified in the laboratory reference frame. The program will then rotate the set of 
rays in the mirror frame.

Type of source,now.

         use  ( 0 ) for point source  
              ( 1 ) for rectangular s.
              ( 2 ) for elliptical  s.
              ( 3 ) for gaussian    s.

X-Z plane source type [ 0-3 ] ? 
0

Source depth. The actual source will be centered on the no-depth position. Use 
         (1) for no depth,
         (2) for flat depth distribution,
         (3) for gaussian depth distribution,
                (4) for a synchrotron source depth distr.

                   Then ? 
Source Depth [ 1-4 ] ? 
1


O.K., got it so far.
         Source distribution now. We may use 
             ( 1 ) for a flat source
             ( 2 )       uniform   s.
             ( 3 )       gaussian  s.
             ( 4 )       synchrotron 
             ( 5 )       conical 
             ( 6 )       exact synchrotron 

Source Angle Distribution [ 1-6 ] ? 
2
Horizontal half-divergence [ (+)x, rads ] ? 
0
                           [ (-)x, rads ] ? 
0
Vertical                   [ (+)z, rads ] ? 
60E-6
                           [ (-)z, rads ] ? 
60E-6
Do you want a Photon energy [ Y/N ] ? 
1
We have these choices :
Single line ......................... 1
Several lines ....................... 2
Uniform source....................... 3
Energy distribution [ 1-3 ] ? 
1
Photon Energy [ 0 ] or Angstroms [ 1 ] ? 
0
Energy [ eV ] ? 
11160

Do you want to store the optical paths (OPD) [Y/N] ? 
0
Do you want to generate the A vectors (electric field) [Y/N] ?
0
Exit from INPUT_SOURCE


Generated          250 rays out of         1000
                   500
                   750
                  1000
Exit from SOURCE
SOURCE => Source has been succesfully generated.

SOURCE procedure completed.

Shadow:: TRACE


Ray Tracing Selected. Begin procedure.


Mode selected [ ? <ret> for HELP ] ? : PROMPT
PROMPT selected.
Call to RESET
Exit from RESET


Mode selected is: 
PROMPT                                                                          
Options: to start anew                 [ 0 ] 
            to restart from a given OE [ 1 ] 
Then ? 
0
Call to INPUT_OE



---------------------------------- S H A D O W  ------------------------------- 
Jan 1986                                         F.Cerrina        ECE - UW      
 
When prompted for a yes/no answer, you may enter:
for   YES  answer      Y, 1
for   NO   answer      anything else
 

Defining Optical Element:  1
Continue ? [ ^Z or %EXIT to terminate OS ] 
1




Do you want a verbose [ 1 ] or terse [ 0 ] output ?
1

Let's define the optical or central axis of the system
for this particular optical element.
By this I mean a "virtual" line that runs throughout
the optical system. Along this line are located the 
"continuation" planes, where the OS is subdivided in the
individual OE. This line does not have to coincide with the
true optical axis, as it is used mainly for bookeeping the
data, but it helps greatly in the data analysis if this
identity is preserved as everything in the program is referredto it.
Once established, you still have complete freedom of
"moving" around the mirrors. 
In the case of a grating, you will have several choices. The 
program may override your specifications for the central axis 
and locate the source and image at the "best" position. 
You will be prompted later for this option.
It is recommended to use CM as units. This is not critical for
 most cases, but it is in the case of diffraction elements.
Optical Element definition:
Incidence Angle ? 			!
10					! The angles here do not matter, as
Source Distance ? 			! they will be replaced by the exact
100					! Bragg angle (if you choose auto
Reflection Angle? 			! tuning of the crystal).
10					!
Image Distance  ? 			!
100
Reflector [ 0 ] or refractor [ 1 ] ? 
0

Lets define the mirror. I may compute its parameters, like the
radius or the axes. This will not affect the rest of the calcu
lations; all the geometrical parameters may be modified later.
Or, you may wish to specify the mirror parameters yourself.


What kind of surface are we dealing with ?
spherical    = 1
elliptical   = 2
toroidal     = 3
paraboloid   = 4
plane        = 5
Codling slit = 6
hyperbolical = 7
cone      = 8
polynomial   = 9

Mirror surface [ 1-9] ? 
5
Is the mirror Cylindrical ? 
0
Are we dealing with a Grating ? 
0

Are we dealing with a crystal [ Y/N ] ? 
1
File containing crystal parameters ?
GAAS.PAR
Automatic Tuning of Crystal [ Y/N ] ?
1
You must then supply the wavelength (or photon energy) at 
which you want the crystal tuned.
Energy, in eV, [ 0 ] or wavelength, in Angs., [ 1 ] ? 
0
Photon Energy ? 
11160
Is the mirror convex [ Y/N ] ? 
0
Reflectivity of Surface. SHADOW may solve the Fresnel equations locally.
Available options:'No reflectivity              .......... 0 
Full polarization dependence .......... 1 
No        "           "      .......... 2 
Reflectivity mode [ 0,1,2 ] ? 
0


Mirror orientation angle. Angles are measured CCW, in deg,
referring to the mirror normal. Alpha=0 is the mirror
sitting at the origin, facing up. Alpha = 90 is the 
mirror standing at your right and facing left when you 
look along the beam STANDING ON THE PREVIOUS MIRROR and so on.
Orientation Angle [ Alpha ] ? 
0

Mirror Dimensions finite [ Y/N ] ?
0

 The Optical Element and the the relative mirror are now fully 
defined. The mirror pole is now located at the "center" of the 
optical element. It is possible to override this situation and 
"move" the mirror without affecting the rest of the system.
 It is also possible to move the "source" without affecting the
rest of the system.
 The movements are expressed in the DEFAULT Mirror Ref. Frame.
 so that if you move BOTH source and mirror the relative
movement is the vector sum of the individual ones.
A word of caution: SOURCE movements and MIRROR movements are
NOT equivalent from the point of view of the whole system.
Do you want to move the Source [ Y/N ] ? 
0
   
--- Mirror rotations and position. ---
We define three angles, as rotations around the three axis.
These rotation are  defined in the program as corrections to
the mirror nominal position; that is, they modify the mirror
position relative to the Default Mirror Reference Frame, where
all the calculations are performed. Remember that rotations
do NOT commute. I apply them in the same order of entry.
CW ROTATIONS are (+) angles. A translation can be also applied to the mirror.
Do you want to move the mirror itself [ Y/N ] ? 
0
Rippled surface [ Y/N ] ? 
0

Any screens in this OE [ Y/N ] ? 
0

Slit at continuation plane [ Y/N ] ? 
0
Extra Image plates [ Y/N ] ? 
0
File containing the source array ? 
BEGIN.DAT
Exit from INPUT
Do you want to modify some inputs ? 
0
Tracing optical element #            1
Call to SETSOUR
Exit from SETSOUR
Call to IMREF
Exit from IMREF
Call to OPTAXIS
Exit from OPTAXIS
Call to MSETUP
Exit from MSETUP
Call to RESTART
Exit from RESTART
Call to MIRROR
Exit from MIRROR
Call to IMAGE
Exit from IMAGE
Call to RESET
Exit from RESET

Do you want to change input mode ? 
0
Call to INPUT_OE



---------------------------------- S H A D O W  ------------------------------- 
Jan 1986                                         F.Cerrina        ECE - UW      

Defining Optical Element:  2
Continue ? [ ^Z or %EXIT to terminate OS ] 
%EXIT
End of session


 
Procedure completed. Return to COMMAND level
 


Procedure completed.

Shadow:: EXIT



Exit to DCL

$ DIR

Directory D13:[XRAYOP.XTAL]

BEGIN.DAT;1             188  12-MAR-1987 12:23  (RWED,RWED,RE,RE)
EFFIC.01;1                1  12-MAR-1987 12:25  (RWED,RWED,RE,RE)
END.00;1                  6  12-MAR-1987 12:23  (RWED,RWED,RE,RE)
END.01;1                 11  12-MAR-1987 12:25  (RWED,RWED,RE,RE)
GAAS.PAR;1                4  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
MIRR.01;1               188  12-MAR-1987 12:25  (RWED,RWED,RE,RE)
OPTAX.01;1                2  12-MAR-1987 12:25  (RWED,RWED,RE,RE)
ROCK_CURVE.P;1           20  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
ROCK_CURVE.PAR;1          3  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
ROCK_CURVE.S;1           20  12-MAR-1987 12:14  (RWED,RWED,RE,RE)
SAVE.DAT;1                8  12-MAR-1987 12:20  (RWED,RWED,RE,RE)
STAR.01;1               188  12-MAR-1987 12:25  (RWED,RWED,RE,RE)
START.00;1                6  12-MAR-1987 12:23  (RWED,RWED,RE,RE)
START.01;1               11  12-MAR-1987 12:25  (RWED,RWED,RE,RE)
TD.FIL;1                  1  12-MAR-1987 12:20  (RWED,RWED,RE,RE)

Total of 15 files, 657 blocks.
$ !
$ ! Notice the P-polarization has smaller average reflectivity.
$ !
$ T EFFIC.01
Of a total of   1000 rays, of which   1000 formed the input set 
     0 were out of the mirror N.    1
The mirror collects   1.0000     of the incoming flux.
The average reflectivities are :
S-pol                      0.29661    
P-pol                      0.27033    
Total                      0.28347    
The overall efficiency of the mirror is : 0.28347    
$ MIRINFO

MINFO> Input file MUST be an ERF (Exit Record File) type from SHADOW
MINFO> Please input filename: 
END.01
MINFO> File read correctly.
MINFO> Title ?
PLANE CRYSTAL REFLECTION
MINFO> Comment ?
To test SHADOW of the rocking curve.
MINFO> Output file ?
MIRR.INF
MINFO> Prepare output to file : MIRR.INF                        
$ !
$ ! Notice the incident and reflected angle have been replaced by the 
$ ! Bragg angle.
$ !
$ T MIRR.INF
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
********************   MIRROR  DESCRIPTION   ********************
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
PLANE CRYSTAL REFLECTION                                                        
To test SHADOW of the rocking curve.                                            
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
Input file specified:END.01                                  
Full file Specification :D13:[XRAYOP.XTAL]END.01;1                                   
Creation Date           :12-MAR-1987 12:25
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 

Surface figure was defined as:        PLANE               
Cilindrical figure                      NO
Element type                            REFLECTOR
Element type                            CRYSTAL
Lattice Spacing                          3.2620290209213856E-08
Bragg Reflection from                  
GAAS.PAR                                                                        
Reflectivity                            OFF
Mirror dimensions                       UNLIMITED
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
Central Axis parameters :
Source Plane Distance                      100.0000000000000    
Image  Plane                               100.0000000000000    
Incidence Angle                            80.19284670377978    
Reflection/Diffraction Angle               80.19284670377978    
 
Mirror parameters                       COMPUTED
Same configuration as Central Axis      NO
Objective focus at                        0.0000000000000000E+00
Image focus at                            0.0000000000000000E+00
Incidence angle                           0.0000000000000000E+00
Parameters used follow:
   Plane mirror 
Source of this O.E. moved               NO
Mirror at pole position ( no mov. )     YES
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
$ !
$ ! Now let us verify that SHADOW also compute the same rocking curve.
$ !
$ PREPLOT
PREPLOT> Input file ? 
STAR.01
Read                 1000 rays.
Each ray has           12 entries.
PREPLOT> How many columns to write out ? 
2
Row [1-12]  : the individual column
Row   [20]  : R = SQRT(X**2 + Y**2 + Z**2)
Row   [21]  : angle from the Y-axis
Row   [22]  : the magnitude of A vector
Row   [23]  : A**2
PREPLOT> Row # 1 : 				!
6						! Z'
PREPLOT>       2 : 				!
23						! Electric field square
Options --- Enter				!
0 for excluding the losses
1 for including losses at a particular O.E.
2 for plotting all the rays .
3 for plotting ONLY the losses (all of them)
4 for plotting ONLY the losses at a given O.E.
PREPLOT> Then ? 
0
Output options :
  [ 0 ] store rays in a file
  [ 1 ] plot directly on screen
  [ 2 ] both
Then ? 
2
PREPLOT> Output file ? 
STAR.PLT
PREPLOT> Terminal type: [0] VT240, [1] TEK 40xx, [2] HIREZ, [3] TEK 4107 : 
1
***********
Found         1000 good points out of        1000
$ !
$ !
$ ! Now you can run SHADOW with a more realistic source !
$ !
$ !
$ LOG
  XRAYOP       logged out at 12-MAR-1987 12:29:33.30
