# The `Test_Rotator` Instrument

*McStas: Unittest for Rotator/Derotator*

## Identification

- **Site:** Tests_optics
- **Author:** Peter Willendrup
- **Origin:** ESS
- **Date:** October 2023

## Description

```text
Unittest for Rotator/Derotator

Example: mcrun test.instr <parameters=values>
```

## Input parameters

Parameters in **boldface** are required; the others are optional.

| Name | Unit | Description | Default |
|------|------|-------------|---------|
| nu | Hz | Rotation frequency | 10 |
| phase | deg | Rotatoion phase | 5 |
| dir | int | Rotation axis direction x=1, y=2, z=3 | 2 |

## Links

- [Source code](Test_Rotator.instr) for `Test_Rotator.instr`.
- A reference/HTML link for more information

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