14.25  The Commodus_I3 McStas Component

ISIS Moderators (Tested with McStas 3.1 (Windows))

Identification

• Author: G. Skoro, based on ViewModerator4 from S. Ansell

• Origin: ISIS

• Date: July 2022

Description

Produces a neutron distribution at the ISIS TS1 or TS2 corresponding moderator front face position. The Face argument determines which TS1 or TS2 beamline is to be sampled by using corresponding file. Neutrons are created having a range of energies determined by the E0 and E1 arguments. Trajectories are produced such that they pass through the moderator face (defined by modXsize and modZsize) and a focusing rectangle (defined by xw, yh and dist). — HOW TO USE —

Example:   Commodus_I3(Face="TS1verBase2016_LH8020_newVM-var_South04_Merlin.mcstas", E0 = E_min, E1 = E_max,
modXsize = 0.12, modZsize = 0.12, xw = 0.094, yh = 0.094, dist = 1.6)

MERLIN simulation; TS1 baseline model. In this example, xw and yh are chosen to be identical to the shutter opening dimension. dist = 1.6 is the real distance to the shutter front face: (This is TimeOffset value (=160 [cm]) from TS1verBase2016_LH8020_newVM-var_South04_Merlin.mcstas file.)

N.B. Absolute normalization: The result of the Mc-Stas simulation will show neutron intensity for beam current of 1 uA.

Input parameters

Parameters in boldface are required; the others are optional.

Links

• Component source code found in file Commodus_I3.comp.