/***************************************************************************
*         McStas instrument definition URL=http://www.mcstas.org
*
* Instrument: Test_Magnetic_Majorana
*
* %Identification
* Written by: Peter Christiansen and Peter Willendrup
* Date: August 2006
* Origin: RISOE
* Release: McStas CVS_080624
* Version: $Revision: 1.3 $
* %INSTRUMENT_SITE: tests
*
* This instrument demonstrates how to use the Pol_simpleBfield
* component with a Majorana field.
*
* %Description
* This instrument demonstrates how to use the component
* Pol_simpleBfield with a so called Majorana field.
*
* See: 
* Seeger et al. NIM A: Volume 457, Issues 1-2 , 11 January 2001, Pages 338-346
*
* Note that there are some sytematic fluctuation with the current solution.
*
* Example: mcrun Test_Magnetic_Majorana.instr
*
* %Parameters
*
* Blarge:        [T]   Large linear decreasing field along x axis (+Blarge to -Blarge).
* Bsmall:        [T]   Constant small component of field along y axis.
* magnetLength:  [m]   Magnet length.
*
* %Link
*
* %End
****************************************************************************/

/* Change name of instrument and input parameters with default values */
DEFINE INSTRUMENT Test_Magnetic_Majorana(Blarge=1.0, Bsmall=0.003, 
					 magnetLength=1.0)
					 
/* The DECLARE section allows us to declare variables or  small      */
/* functions in C syntax. These may be used in the whole instrument. */
DECLARE
%{
%}

/* The INITIALIZE section is executed when the simulation starts     */
/* (C code). You may use them as component parameter values.         */
INITIALIZE
%{
%}

/* Here comes the TRACE section, where the actual      */
/* instrument is defined as a sequence of components.  */
TRACE

/* The Arm() class component defines reference points and orientations  */
/* in 3D space. Every component instance must have a unique name. Here, */
/* Origin is used. This Arm() component is set to define the origin of  */
/* our global coordinate system (AT (0,0,0) ABSOLUTE). It may be used   */
/* for further RELATIVE reference, Other useful keywords are : ROTATED  */
/* EXTEND GROUP PREVIOUS. Also think about adding a neutron source !    */
/* Progress_bar is an Arm displaying simulation progress.               */
COMPONENT Origin = Progress_bar()
     AT (0,0,0) ABSOLUTE

COMPONENT source = 
Source_simple(radius = 0.001, dist = 1.0, xw = 0.001, yh = 0.001, 
	      Lambda0 = 15, dLambda = 14.0, flux = 1)
     AT (0, 0, 0) RELATIVE Origin

COMPONENT polSetter =
Set_pol(px=1)
     AT (0, 0, 0.5) RELATIVE Origin

COMPONENT pollambdaMonitor1x = 
PolLambda_monitor(xw=0.1, yh=0.1, 
		  nlam=100, Lmin=0.0, Lmax=30.0, npol=21, 
		  mx=1, my=0, mz=0, filename="pollambdaMon1x.data")
     AT (0, 0, 0.7) RELATIVE Origin

COMPONENT pollambdaMonitor1y =
PolLambda_monitor(xw=0.1, yh=0.1,
		  nlam=100, Lmin=0.0, Lmax=30.0, npol=21,
		  mx=0, my=1, mz=0, filename="pollambdaMon1y.data")
     AT (0, 0, 0.75) RELATIVE Origin

COMPONENT pollambdaMonitor1z =
PolLambda_monitor(xw=0.1, yh=0.1,
		  nlam=100, Lmin=0.0, Lmax=30.0, npol=21,
		  mx=0, my=0, mz=1, filename="pollambdaMon1z.data")
     AT (0, 0, 0.8) RELATIVE Origin

COMPONENT armMagnet = Arm()
     AT (0,0,1) RELATIVE Origin

// The By field is set to rotate the spin 180 degrees for neutrons of wavelenth
// 5 AA
COMPONENT msf =
Pol_simpleBfield(xw=0.08, yh=0.08, length=magnetLength, 
		 Bx=Blarge, By=Bsmall, Bz=0,
		 fieldFunction=majorana_magnetic_field)
     AT (0, 0, 0) RELATIVE armMagnet

COMPONENT msfCp = COPY(msf)
     AT (0, 0, 0) RELATIVE armMagnet

COMPONENT armMagnetEnd = Arm()
     AT (0,0,magnetLength) RELATIVE armMagnet

COMPONENT pollambdaMonitor2x =
PolLambda_monitor(xw=0.1, yh=0.1,
		  nlam=100, Lmin=0.0, Lmax=30.0, npol=21,
		  mx=1, my=0, mz=0, filename="pollambdaMon2x.data")
     AT (0, 0, 0.1) RELATIVE armMagnetEnd

COMPONENT pollambdaMonitor2y =
PolLambda_monitor(xw=0.1, yh=0.1,
		  nlam=100, Lmin=0.0, Lmax=30.0, npol=21,
		  mx=0, my=1, mz=0, filename="pollambdaMon2y.data")
     AT (0, 0, 0.1) RELATIVE armMagnetEnd

COMPONENT pollambdaMonitor2z =
PolLambda_monitor(xw=0.1, yh=0.1,
		  nlam=100, Lmin=0.0, Lmax=30.0, npol=21,
		  mx=0, my=0, mz=1, filename="pollambdaMon2z.data")
     AT (0, 0, 0.1) RELATIVE armMagnetEnd

COMPONENT mpollambdaMonitor2x =
MeanPolLambda_monitor(xw=0.1, yh=0.1,
		      nlam=100, Lmin=0.0, Lmax=30.0,
		      mx=1, my=0, mz=0, filename="mpollambdaMon2x.data")
     AT (0, 0, 0.1) RELATIVE armMagnetEnd

COMPONENT mpollambdaMonitor2y =
MeanPolLambda_monitor(xw=0.1, yh=0.1,
		      nlam=100, Lmin=0.0, Lmax=30.0,
		      mx=0, my=1, mz=0, filename="mpollambdaMon2y.data")
     AT (0, 0, 0.1) RELATIVE armMagnetEnd

COMPONENT mpollambdaMonitor2z =
MeanPolLambda_monitor(xw=0.1, yh=0.1,
		      nlam=100, Lmin=0.0, Lmax=30.0,
		      mx=0, my=0, mz=1, filename="mpollambdaMon2z.data")
     AT (0, 0, 0.1) RELATIVE armMagnetEnd

/* This section is executed when the simulation ends (C code). Other    */
/* optional sections are : SAVE                                         */
FINALLY
%{
  %}
/* The END token marks the instrument definition end */
END