First tries using McStas

[artus at obiwan.kri.physik.uni-muenchen.de]

Dear Kristian,

in the last days since our return from Denmark I've installed your
program McStas on my machine here. Right now I'm trying to get my
first "instrument" running. I have some 'beginners problems' and now allow
myself to ask for help.
I wanted to simulate a simple straight neutron guide with m=2 for left 
and right faces and m=3 for top and bottom faces. But the component
Guide only allows one kind of coating. It is not quite clear to me
from the manual how to build such a guide out of four Mirror
components. The manual says that Mirrors can be used to assemble a
guide but it says also that a Mirror lies in the xy-plane. Wouldn't
one need Mirrors lying parallel to the z-axis to build a guide? May be 
the use of different coatings within the same guide can be implemented 
within the Guide component in some future release?

To make things easier I tried to set up the instrument with m=2 for
all faces. But trying to compile it with McStas ends with:

artus at obiwan:/home/artus/mcstas/resi1 > mcstas resi1.instr 
parse error, expecting `"AT"' at line 37.
Errors encountered during parse.
artus at obiwan:/home/artus/mcstas/resi1 > 

The AT is expected in the END line? 
I cannot find any error in resi1.instr:

DEFINE INSTRUMENT RESI1()

TRACE

COMPONENT a1 = Arm()
  AT (0,0,0) ABSOLUTE

COMPONENT source = Source_flat(
	radius = 0.050,
	dist = 2.000,
	xw = 0.020, yh = 0.060,
	E0 = 81.804,	/* = 1A*/
	dE = 1.0)	/* =0.99394A - 1.00617A 
  AT (0,0,0) RELATIVE a1

COMPONENT guide1 = Guide(
	w1 = 0.020
	h1 = 0.060
	w2 = 0.020
	h2 = 0.060
	l = 11.500
	R0 = 1.0
	Qc = 0.0214
	alpha = 5.617
	m = 2
	W = 0.0033)
  AT (0,0,2) RELATIVE a1 

COMPONENT mon = Monitor(
	xmin = -0.01,
	xmax = 0.01,
	ymin = -0.03,
	ymax = 0.03)
  AT (0,0,13.5) RELATIVE a1

END

What is wrong with the input file? The example files on the CD
unfortunately don't contain a Mirror or Guide component for
comparison.

Furthermore I've tried to use mcdisplay on the example files but this
also ends with an error:

artus at obiwan:/home/artus/mcstas/example > mcdisplay linup-1.instr 
Can't locate PGPLOT.pm in @INC (@INC contains: /usr/lib/perl5/i586-linux/5.00404 /usr/lib/perl5 /usr/lib/perl5/site_perl/i586-linux /usr/lib/perl5/site_perl .) at /usr/local/bin/mcdisplay line 6.
BEGIN failed--compilation aborted at /usr/local/bin/mcdisplay line 6.
artus at obiwan:/home/artus/mcstas/example > 

I have installed pgplot from the CD. The pgplot examples are running
and 

PGPLOT_DIR="/usr/local/pgplot/"; export PGPLOT_DIR
PGPLOT_DEV="/xwin"; export PGPLOT_DEV

is added to my .bashrc file.

I couldn't find the file PGPLOT.pm anywhere on the harddisk. I also
didn't find any information about this in the installation guidelines
of pgplot. What is wrong?

Thank you very much for your help and

best wishes from Garching,

Georg

*********************************************

Dr. Georg Artus
Technische Universität München
FRM-II Reaktorstation
D-85747 Garching

Tel: +49 (0)89/289-14018
Fax: +49 (0)89/289-12112
E-mail: gartus at ph.tum.de