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[ Identification | Description | Input parameters | Output parameters | Links ]
The PSD_curved component
Curved linear 1D MSGC PSD
Identification
- Author: Thomas C Hansen
- Origin: ILL (Dif/D20)
- Date: 07 March 2000
- Version: 1.0
Description
A curved linear 1D PSD monitor using a cylindrical projection. This detector type is commonly used in constant wavelength neutron powder diffraction, based either on multiwire- (MWGC) or microstrip- (MSGC) gaschamber technology. This implementation is mainly pushed by the MSGC realisation (D20) of such a PSD, as done on D20 at ILL. So some kind of 'polygonality' effect resulting from the polygonal arrangement of MSGC plates will be considered in the near future by an approximation of the electron avalanche trace in the electrical field.
Input parameters
Parameters in boldface are required; the others are optional.| Name | Unit | Description | Default |
|---|---|---|---|
| radius | m | Radius of detector at center of MSGC plate (=radius in PSD_entry + gap) (1.471) | |
| height | m | Height of detector (=height in PSD_entry) (0.15) | |
| nd | 1 | Number of cells (=nd in PSD_entry) (1536) | |
| pitch | deg | angular pitch (=pitch in PSD_entry) (0.1) | |
| gap | m | gaschamber detection gap (0.053) | |
| filename | string | Name of file in which to store the detector image (NULL) | |
| sign | 1 | Chirality of 1st diffractometer axis=sign[takeoff of d20adapt.instr] (-1) | |
| tt0 | deg | Angular position of 1st PSD cell (=tt0 in PSD_entry) (0) | |
| pdet | bar | Pressure of 3He detection gas (1.2) | |
| pT_trace | m | Average effective length of proton/tritium trace (0.005) | |
| period | 1 | Number of detection cells per MSGC plate (=period in PSD_entry) (32) | |
| cellwidth | m | Width of one detection cell on a MSGC plate (0.002568) |
Output parameters
| Name | Unit | Description | Default |
|---|---|---|---|
| PSD_N | *1 | Array of neutron counts | |
| PSD_p | *1.0 | Array of neutron weight counts | |
| PSD_p2 | *1.0 | Array of second moments | |
| alpha | rad | Angle covered by one MSGC plate | |
| R1 | m | PSD radius at MSGC edge |
Links
- Source code for
PSD_curved.comp. - Source code of d20adapt.instr, where this component is used
- Source code of PSD_entry.comp, a corresponding entry window
[ Identification | Description | Input parameters | Output parameters | Links ]
Generated automatically by McDoc, Kristian Nielsen <kristian.nielsen@risoe.dk> / Jan 22 2001
