MARI
MARI is a direct-geometry spectrometer at the ISIS Neutron and Muon Source. [1]
References
Versions
MARI (default)
MARI
For details on the parameters associated with the MARI version, please see the MARI data.
Models
PyChop_fit (default)
PyChop_fit
This is the recommended PyChop_fit model - it is an alias for the PyChop_fit_v1 model, which is the model actually containing the data.
Important
PyChop_fit refers to the best version of this model - using a specific version may run the risk using a model with known bugs or other issues and is not advisable unless replicating the results of a given version of the model.
PyChop_fit_v1
This section contains the data for the MARI instrument associated with the PyChop_fit_v1 model. For more information about how the model works and its implementation, please see resins.models.pychop.PyChopModelFermi. For more information on the model parameters, please see PyChop_fit_v1 model data.
Configurations:
Data
name: "MARI"
default_version: "MARI"
version:
MARI:
default_model: "PyChop_fit"
models:
PyChop_fit: "PyChop_fit_v1"
PyChop_fit_v1:
function: "pychop_fit_fermi"
citation: ['R. I. Bewley, R. A. Ewings, M. D. Le, T. G. Perring and D. J. Voneshen, 2018. PyChop', 'https://mantidproject.github.io/docs-versioned/v6.10.0/interfaces/direct/PyChop.html']
parameters:
d_chopper_sample: 1.689
d_sample_detector: 4.022
aperture_width: 0.06667
theta: 13.0
defaults:
e_init: 500
chopper_frequency: 400
frequency_matrix: [[0], [1]]
moderator:
type: 2
scaling_function: None
measured_wavelength: [4.024, 5.6898, 2.325, 2.848, 1.5224, 3.4331, 1.8009, 1.1167]
measured_width: [53.2, 62, 39.2, 44.8, 18.8, 48.8, 27.2, 12.4]
parameters: [38.6, 0.5226]
detector:
type: 2
phi: 0.0
depth: 0.025
sample:
type: 2
thickness: "2e-2"
width: 0.019
height: "5e-2"
gamma: 0.0
choppers:
Disk:
distance: 7.85
nslot: 4
slot_width: 65
slot_ang_pos: [0, 36.48, 72.76, 145.52]
guide_width: 60
radius: 367
num_disk: 1
is_phase_independent: True
default_phase: "0"
Fermi:
distance: 10.05
aperture_distance: 7.19
configurations:
chopper_package:
default_option: "A"
A:
pslit: 0.00076
radius: 0.049
rho: 1.3
tjit: 0.0
restrictions: {'e_init': [0, 2000], 'chopper_frequency': [50, 601, 50]}
B:
pslit: 0.00114
radius: 0.049
rho: 0.82
tjit: 0.0
restrictions: {'e_init': [0, 2000], 'chopper_frequency': [50, 601, 50]}
C:
pslit: 0.00152
radius: 0.049
rho: 0.58
tjit: 0.0
restrictions: {'e_init': [0, 2000], 'chopper_frequency': [50, 601, 50]}
G:
pslit: 0.00038
radius: 0.01
rho: 0.8
tjit: 0.0
restrictions: {'e_init': [0, 181], 'chopper_frequency': [50, 601, 50]}
R:
pslit: 0.001143
radius: 0.049
rho: 1.3
tjit: 0.0
restrictions: {'e_init': [0, 2000], 'chopper_frequency': [50, 601, 50]}
S:
pslit: 0.00228
radius: 0.049
rho: 1.3
tjit: 0.0
restrictions: {'e_init': [0, 2000], 'chopper_frequency': [50, 601, 50]}