[ Identification | Description | Input parameters | Output parameters | Links ]

# The `HET` Instrument

HET: High Energy Transfer Chopper Spectrometer

## Identification

- Site: ISIS
- Author: Dickon Champion
- Origin: ISIS (UK)
- Date: 22nd Jan 2004.
- Version: 1.2

## Description

    This instrument is a simple model of the HET spectrometer at the ISIS neutron
    facility. The input arguments are hardwired so that the Fermi chopper position
    is 10 metres from the moderator. This instrument uses the FC module written by
    Andrew Garret which comes with no guarantees as to its accuracy in modelling the
    Fermi Chopper.

    Example: mcrun HETfull.instr E_0=443.0,E_1=470.0,chop_select=450.0,nu_chop=600.0, type=2

## Input parameters

Parameters in boldface are required; the others are optional.

Name | Unit | Description | Default
--- | --- | --- | ---
E_0 | meV | lowest energy sampled | 443.0
E_1 | meV | highest energy sampled | 470.0
chop_select | meV | energy selected by chopper | 450.0
nu_chop | Hz | frequency of chopper rotation | 600.0
type | sloppy chopper = 1, B chopper = 2 | chopper package selected | 2

## Links

- Source code for `HET.instr`.

[ Identification | Description | Input parameters | Output parameters | Links ]