[neutron-mc] Problems in Powder2.comp

[Chapon, LC (Laurent)]

Hi, 

 

I think there are possibly two problems in the component Powder2: 

 

Line  105 : I think it should be l=v*(dt-t0) instead of v*dt. The
attenuation due to scattering was therefore much larger than expected.  

 

 103   dt = rand01()*(t1 - t0) + t0; /* Time of scattering */

 104   PROP_DT(dt);                 /* Point of scattering */

 105   l = v*dt;                          /* Penetration in sample */

 

The other problem is on line 170 : When using focus_aw and focus_ah. The
angles should be provided in radians and not degrees as suggested in the
component. Otherwise, DEG2RAD should be use to convert the focus_aw and
focus_ah parameters when calling the routine
randvec_target_rect_angular. 

 

170       randvec_target_rect_angular(&vx, &vy, &vz, &solid_angle, 

171                                               aim_x, aim_y, aim_z,
focus_aw, focus_ah, ROT_A_CURRENT_COMP);

 

 

______________________________________

Dr Laurent Chapon

Instrument Scientist

ISIS department

Bldg R3

Rutherford Appleton Laboratory

Chilton, Didcot

OX11 0QX

UK

+44(0)1235-446090

 

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