[ Identification | Description | Input parameters | Links ]

The ISIS_SANS2d Instrument

Identification

• Site: ISIS
• Author: Richard Heenan with edits by Peter Willendrup
• Origin: ISIS, DTU Fysik
• Date: 2014

Description

This instrument models the ISIS TS2 SANS2d instrument up to the sample position.

From the author:
IMPORTANT: The instrument model does not currently include a correct moderator description
- and the results it produces have not been validated against experimental results.
The actual bender is continuously curved, here use straight segments approx.with gravity.
1/7/10 L1=4m  increased gap between bender exit and S1 slit from .247 to .286m
At 4m we actually use 1.75 to 16.5 angstrom.
Note "2m guides" are actually 1.985m long (new ones will be 1.981m) so "real gaps" are included below, losses are pro-rata the gap/guide lengths.
Both rear & front detectors are 980mm square and offset 150 above beam (would only use 100mm with hindsight)
Rear detector can be offset -300mm or +269mm sideways.
Front detector is closest at approx 1.4m,  furthest at approx((read det position) - 1.6m) , offset  up to -1200mm sideways
there are 2 baffles between front & rear detector
NIMROD (W5) spectrum might better than SANS2d (E2) spectrum for liquid H2 face incurent use.
Stu Ansell's McStas spectra for TS-2 actually have no angle variation included.
In reality spectra and backgrounds will vary, fast background is likely much higher on ZOOM(E1) than SANS2d (E2)
RKH 2014

Input parameters

Links

• Source code for ISIS_SANS2d.instr.

[ Identification | Description | Input parameters | Links ]