/*******************************************************************************
*
* McStas, neutron ray-tracing package
*         Copyright 1997-2002, All rights reserved
*         Risoe National Laboratory, Roskilde, Denmark
*         Institut Laue Langevin, Grenoble, France
*
* Instrument: SANS
*
* %Identification
* Written by: <a href="mailto:kim.lefmann@risoe.dk">Kim Lefmann</a>
* Date: 19th Dec 2003.
* Origin: <a href="http://www.risoe.dk">Risoe</a>
* Release: McStas 1.6
* Version: $Revision: 1.4 $
* %INSTRUMENT_SITE: tests
*
* Test instrument for the Sans_spheres component. No guide / velocity selector
* etc. Will be developed further at at later time.
*
* %Description
* Very simple test instrument for the Sans_spheres component
*
* Example: mcrun SANS.instr r=100, PHI=1e-3, Delta_Rho=0.6, Sigma_a=50, Qmax=0.3
*
* %Parameters
* INPUT PARAMETERS:
* Lambda    : Mean wavelength of neutrons      [AA]
* D_lambda  : Wavelength spread of neutrons    [AA]
* r   : Radius of scattering hard spheres [AA]
* PHI   : Particle volume fraction [1]
* Delta_Rho : Excess scattering length density (fm/AA^3)
* Sigma_a : Absorption cross section density at 2200 m/s [m^-1]
* Qmax    : Maximum momentum transfer [AA^-1]
*
* %Link
* *
* %End
*******************************************************************************/
DEFINE INSTRUMENT Risoe_sans(Lambda=6, D_lambda=0.05, r=100, PHI=1e-3, Delta_Rho=0.6, Sigma_a=50, Qmax=0.3)
DECLARE
%{
%}
INITIALIZE
%{
%}
TRACE

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

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

COMPONENT source = Source_flux_lambda(
    radius = 0.02, dist = 3, xw = 0.01, yh = 0.01,
    lambda_0 = Lambda, d_lambda = D_lambda, flux = 1e8)
  AT (0, 0, 0) RELATIVE arm

COMPONENT coll1 = Slit(
    radius = 0.005)
  AT (0, 0, 3) RELATIVE arm

COMPONENT coll2 = Slit(
    radius = 0.005)
  AT (0, 0, 6) RELATIVE arm

COMPONENT sample = Sans_spheres(R=r, Phi=PHI, Delta_rho=Delta_Rho, sigma_a=Sigma_a, qmax=Qmax)
   AT (0,0,0.2) RELATIVE coll2

COMPONENT detector = PSD_monitor(
    nx = 128, ny = 128, filename = "PSD.dat", xmin = -0.3,
    xmax = 0.3, ymin = -0.3, ymax = 0.3)
  AT (0, 0, 3) RELATIVE sample

COMPONENT Ldetector = L_monitor(
    nchan = 1000, filename = "Edet.dat", xmin = -0.3,
    xmax = 0.3, ymin = -0.3, ymax = 0.3, Lmin = 5.5,
    Lmax = 6.5)
  AT (0, 0, 3.01) RELATIVE sample





FINALLY
%{
%}
END