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

The PSD_entry component

Entry window of a curved linear gaschamber PSD

Identification

• Author: Thomas C Hansen
• Origin: ILL (Dif/D20)
• Date: 07 March 2000
• Version: 1.1

Description

Aluminium entry window for a curved linear position sensitive detector (PSD),
as used in constant wavelength neutron powder diffraction (ILL Grenoble: D20).
Normally, this component is always used in front of a PSD_curved component.

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
radius	m	Outer radius of detector entry window (=radius-gap in PSD_curved) (1.418)
height	m	Height of detector (=height in PSD_curved) (0.15)
nd	1	Number of cells (=nd in PSD_curved) (1536)
pitch	deg	angular pitch (=pitch in PSD_curved) (0.1)
gap	m	Thickness of entry window (0.007)
tt0	deg	detection angle of first cell (=tt0 in PSD_curved) (0)
pack	1	Packing density of window material
Vc	AA**3	Unit cell volume of window material
sigma_a	barn	Absorption cross section
q	1/AA	Wavevector
j	1	Multiplicity
F2	fm**2	Structure factor
DW	1/AA**2	Debye-Waller factor
period	1	Number of cells on one MSGC plate (=period in PSD_curved) (32)
sign	1	Chirality of 1st diffractometer axis=sign[takeoff of d20adapt.instr] (-1)

Output parameters

Name	Unit	Description	Default
my_s_v2	m/s**2	Attenuation factor due to elastic coherent scattering, multiplied by neutron velocity**2
my_a_v	1/s	Attenuation factor due to absorption, multiplied by neutron velocity
q_v	m/s	Corresponding velocity of wavevector Q

Links

• Source code for PSD_entry.comp.
• Source code of d20adapt.instr, where this component is used
• The corresponding detector PSD_curved.comp

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

Generated automatically by McDoc, Kristian Nielsen <kristian.nielsen@risoe.dk> / Jan 22 2001

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Last Modified: Tuesday, 22-Jun-2004 14:04:09 CEST