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[ Identification | Description | Input parameters | Output parameters | Links ]
The ESS_IN5_reprate Instrument
Identification
- Site: ESS
- Author: Kim Lefmann (kim.lefmann@risoe.dk), Helmuth Schober, Feri Mezei
- Origin:ESS
- Date: September 20, 2006
- Version: 1.3 Updated with respect to McStas 1.12b version which does not compile
Description
McStas instrument for simulating IN5-TYPE (cold chopper) multi-frame spectrometer at ESS LPTS
Input parameters
Parameters in boldface are required; the others are optional.| Name | Unit | Description | Default |
|---|---|---|---|
| Lam_min | AA | Minimum wavelength emitted by the moderator | 4.9 |
| Lam_max | AA | Maximum wavelength emitted by the moderator | 5.1 |
| Lam_target | AA | Target wavelength for the monochromating crystal | 5 |
| Pulse_width | s | Length of the long pulse. Default to 2 ms. | 0.002 |
| Twopulses | 1 | Possibility of emitting neutrons from a second pulse. Default 0. | 0 |
| GUI_start | m | Distance from moderator to guide start | 1.5 |
| FO1_DIST | m | Distance from moderator to FO1 chopper | 6 |
| L_ballistic_begin | m | Length of expanding ballistic section in the beginning of the guide | 19.5 |
| L_ballistic_end | m | Length of compressing ballistic section in the end of the guide | 17 |
| Length | moderator to F2 | [m] Total length of spectrometer | 100 |
| SAMPLE_DIST | m | Distance from F2 to sample | 1.2 |
| DETECTOR_DIST | m | Length sample-detector | 4 |
| GUI_h | m | Height of guide opening at entry | 0.105 |
| GUI_w | m | Width of guide opening at entry H1-H4: [m] Height of guide elements W1-W4: [m] Width of guide elements | 0.1 |
| GUI_GAP | m | Gap between guides due to chopper hardware | 0.05 |
| H1 | 0.167 | ||
| W1 | 0.116 | ||
| H2 | 0.185 | ||
| W2 | 0.15 | ||
| H3 | 0.19 | ||
| W3 | 0.15 | ||
| H4 | 0.213 | ||
| W4 | 0.14 | ||
| H_chop | m | Height at F2 chopper position | 0.075 |
| W_chop | m | Width at F2 chopper position | 0.03 |
| H_end | m | Height of guide opening at exit | 0.042 |
| W_end | m | Width of guide opening at exit | 0.0215 |
| ALPHA | m | Parameter for supermirrors in guides, Swiss Neutronics best at 3.4 | 3.4 |
| M | 1 | Parameter for supermirrors in guides, Swiss Neutronics best at 4 | 3.5 |
| F_slow1 | Hz | Frequency of the FO1 chopper | 16.6667 |
| F_slow2 | Hz | Frequency of the FO2 chopper | 0 |
| F_fast1 | Hz | Frequency of the F1 chopper | 0 |
| F_fast2 | Hz | Frequency of the F2 chopper | 200 |
| N_fast | 1 | Number of symmetric openings in the fast F choppers | 1 |
| SLOW1_THETA | deg | Opening angle of the FO1 chopper | 120 |
| FO3 | if 1, same as F2; if 2, half of F2, etc. | [1] Inverse frequency of FO3 chopper | 1 |
| THETA_fast1 | deg | Opening angle of the F1 chopper | 180 |
| FAST_THETA | deg | Opening angle of the F2 chopper | 5 |
| Gamma | 0=elastic | [meV] Width of sample quasielastic scattering | 0 |
| Etun | meV | Tunneling energy | 1 |
| V_HOLE | m | Radius of hole in V sample (must be smaller than the outer radius: 0.01) FRAC_QUASIEL [1] Fraction of the sample that scatters quasielastically | 0 |
| FRAC_QUASIEL | 0 | ||
| FRAC_TUNNEL | 0 | ||
| TT | deg | 2T (or a4) scattering angle | 50 |
| RES_DE | meV | Adjustable zoom for energy monitor at detector position | 0.5 |
Links
- Source code for
ESS_IN5_reprate.instr. - The ESS-Rencurel website.
[ Identification | Description | Input parameters | Output parameters | Links ]
Generated automatically by McDoc, Peter Willendrup <peter.willendrup@risoe.dk> / Tue Aug 10 09:44:40 2010
