Create a wavelength lookup table for LoKI#

[1]:

import scipp as sc
from ess.reduce import unwrap
from ess.reduce.nexus.types import AnyRun

Setting up the workflow#

Note here that for now, we have no chopper in the beamline. This should be added in the next iteration.

[2]:

source_position = sc.vector([0, 0, 0], unit='m')

wf = unwrap.LookupTableWorkflow()
wf[unwrap.DiskChoppers[AnyRun]] = {}
wf[unwrap.SourcePosition] = source_position
wf[unwrap.NumberOfSimulatedNeutrons] = 200_000  # Increase this number for more reliable results
wf[unwrap.SimulationSeed] = 1234
wf[unwrap.PulseStride] = 1
wf[unwrap.LtotalRange] = sc.scalar(9.0, unit="m"), sc.scalar(35.0, unit="m")
wf[unwrap.DistanceResolution] = sc.scalar(0.1, unit="m")
wf[unwrap.TimeResolution] = sc.scalar(250.0, unit='us')

Compute the table#

[3]:

table = wf.compute(unwrap.LookupTable)
table.array

Downloading file 'ess/ess.h5' from 'https://github.com/scipp/tof-sources/raw/refs/heads/main/1/ess/ess.h5' to '/home/runner/.cache/tof'.

[3]:

scipp.DataArray (1.16 MB)

Dimensions:
- distance: 264
- event_time_offset: 287

Coordinates: (2)

distance

(distance)

float64

m

8.8, 8.9, ..., 35.000, 35.100

Values:
array([ 8.8,  8.9,  9. ,  9.1,  9.2,  9.3,  9.4,  9.5,  9.6,  9.7,  9.8,
        9.9, 10. , 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9,
       11. , 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12. ,
       12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, 12.9, 13. , 13.1,
       13.2, 13.3, 13.4, 13.5, 13.6, 13.7, 13.8, 13.9, 14. , 14.1, 14.2,
       14.3, 14.4, 14.5, 14.6, 14.7, 14.8, 14.9, 15. , 15.1, 15.2, 15.3,
       15.4, 15.5, 15.6, 15.7, 15.8, 15.9, 16. , 16.1, 16.2, 16.3, 16.4,
       16.5, 16.6, 16.7, 16.8, 16.9, 17. , 17.1, 17.2, 17.3, 17.4, 17.5,
       17.6, 17.7, 17.8, 17.9, 18. , 18.1, 18.2, 18.3, 18.4, 18.5, 18.6,
       18.7, 18.8, 18.9, 19. , 19.1, 19.2, 19.3, 19.4, 19.5, 19.6, 19.7,
       19.8, 19.9, 20. , 20.1, 20.2, 20.3, 20.4, 20.5, 20.6, 20.7, 20.8,
       20.9, 21. , 21.1, 21.2, 21.3, 21.4, 21.5, 21.6, 21.7, 21.8, 21.9,
       22. , 22.1, 22.2, 22.3, 22.4, 22.5, 22.6, 22.7, 22.8, 22.9, 23. ,
       23.1, 23.2, 23.3, 23.4, 23.5, 23.6, 23.7, 23.8, 23.9, 24. , 24.1,
       24.2, 24.3, 24.4, 24.5, 24.6, 24.7, 24.8, 24.9, 25. , 25.1, 25.2,
       25.3, 25.4, 25.5, 25.6, 25.7, 25.8, 25.9, 26. , 26.1, 26.2, 26.3,
       26.4, 26.5, 26.6, 26.7, 26.8, 26.9, 27. , 27.1, 27.2, 27.3, 27.4,
       27.5, 27.6, 27.7, 27.8, 27.9, 28. , 28.1, 28.2, 28.3, 28.4, 28.5,
       28.6, 28.7, 28.8, 28.9, 29. , 29.1, 29.2, 29.3, 29.4, 29.5, 29.6,
       29.7, 29.8, 29.9, 30. , 30.1, 30.2, 30.3, 30.4, 30.5, 30.6, 30.7,
       30.8, 30.9, 31. , 31.1, 31.2, 31.3, 31.4, 31.5, 31.6, 31.7, 31.8,
       31.9, 32. , 32.1, 32.2, 32.3, 32.4, 32.5, 32.6, 32.7, 32.8, 32.9,
       33. , 33.1, 33.2, 33.3, 33.4, 33.5, 33.6, 33.7, 33.8, 33.9, 34. ,
       34.1, 34.2, 34.3, 34.4, 34.5, 34.6, 34.7, 34.8, 34.9, 35. , 35.1])

event_time_offset

(event_time_offset)

float64

µs

0.0, 249.750, ..., 7.118e+04, 7.143e+04

Values:
array([    0.        ,   249.75024975,   499.5004995 ,   749.25074925,
         999.000999  ,  1248.75124875,  1498.5014985 ,  1748.25174825,
        1998.001998  ,  2247.75224775,  2497.5024975 ,  2747.25274725,
        2997.002997  ,  3246.75324675,  3496.5034965 ,  3746.25374625,
        3996.003996  ,  4245.75424575,  4495.5044955 ,  4745.25474525,
        4995.004995  ,  5244.75524476,  5494.50549451,  5744.25574426,
        5994.00599401,  6243.75624376,  6493.50649351,  6743.25674326,
        6993.00699301,  7242.75724276,  7492.50749251,  7742.25774226,
        7992.00799201,  8241.75824176,  8491.50849151,  8741.25874126,
        8991.00899101,  9240.75924076,  9490.50949051,  9740.25974026,
        9990.00999001, 10239.76023976, 10489.51048951, 10739.26073926,
       10989.01098901, 11238.76123876, 11488.51148851, 11738.26173826,
       11988.01198801, 12237.76223776, 12487.51248751, 12737.26273726,
       12987.01298701, 13236.76323676, 13486.51348651, 13736.26373626,
       13986.01398601, 14235.76423576, 14485.51448551, 14735.26473526,
       14985.01498501, 15234.76523477, 15484.51548452, 15734.26573427,
       15984.01598402, 16233.76623377, 16483.51648352, 16733.26673327,
       16983.01698302, 17232.76723277, 17482.51748252, 17732.26773227,
       17982.01798202, 18231.76823177, 18481.51848152, 18731.26873127,
       18981.01898102, 19230.76923077, 19480.51948052, 19730.26973027,
       19980.01998002, 20229.77022977, 20479.52047952, 20729.27072927,
       20979.02097902, 21228.77122877, 21478.52147852, 21728.27172827,
       21978.02197802, 22227.77222777, 22477.52247752, 22727.27272727,
       22977.02297702, 23226.77322677, 23476.52347652, 23726.27372627,
       23976.02397602, 24225.77422577, 24475.52447552, 24725.27472527,
       24975.02497502, 25224.77522478, 25474.52547453, 25724.27572428,
       25974.02597403, 26223.77622378, 26473.52647353, 26723.27672328,
       26973.02697303, 27222.77722278, 27472.52747253, 27722.27772228,
       27972.02797203, 28221.77822178, 28471.52847153, 28721.27872128,
       28971.02897103, 29220.77922078, 29470.52947053, 29720.27972028,
       29970.02997003, 30219.78021978, 30469.53046953, 30719.28071928,
       30969.03096903, 31218.78121878, 31468.53146853, 31718.28171828,
       31968.03196803, 32217.78221778, 32467.53246753, 32717.28271728,
       32967.03296703, 33216.78321678, 33466.53346653, 33716.28371628,
       33966.03396603, 34215.78421578, 34465.53446553, 34715.28471528,
       34965.03496503, 35214.78521479, 35464.53546454, 35714.28571429,
       35964.03596404, 36213.78621379, 36463.53646354, 36713.28671329,
       36963.03696304, 37212.78721279, 37462.53746254, 37712.28771229,
       37962.03796204, 38211.78821179, 38461.53846154, 38711.28871129,
       38961.03896104, 39210.78921079, 39460.53946054, 39710.28971029,
       39960.03996004, 40209.79020979, 40459.54045954, 40709.29070929,
       40959.04095904, 41208.79120879, 41458.54145854, 41708.29170829,
       41958.04195804, 42207.79220779, 42457.54245754, 42707.29270729,
       42957.04295704, 43206.79320679, 43456.54345654, 43706.29370629,
       43956.04395604, 44205.79420579, 44455.54445554, 44705.29470529,
       44955.04495504, 45204.7952048 , 45454.54545455, 45704.2957043 ,
       45954.04595405, 46203.7962038 , 46453.54645355, 46703.2967033 ,
       46953.04695305, 47202.7972028 , 47452.54745255, 47702.2977023 ,
       47952.04795205, 48201.7982018 , 48451.54845155, 48701.2987013 ,
       48951.04895105, 49200.7992008 , 49450.54945055, 49700.2997003 ,
       49950.04995005, 50199.8001998 , 50449.55044955, 50699.3006993 ,
       50949.05094905, 51198.8011988 , 51448.55144855, 51698.3016983 ,
       51948.05194805, 52197.8021978 , 52447.55244755, 52697.3026973 ,
       52947.05294705, 53196.8031968 , 53446.55344655, 53696.3036963 ,
       53946.05394605, 54195.8041958 , 54445.55444555, 54695.3046953 ,
       54945.05494505, 55194.80519481, 55444.55544456, 55694.30569431,
       55944.05594406, 56193.80619381, 56443.55644356, 56693.30669331,
       56943.05694306, 57192.80719281, 57442.55744256, 57692.30769231,
       57942.05794206, 58191.80819181, 58441.55844156, 58691.30869131,
       58941.05894106, 59190.80919081, 59440.55944056, 59690.30969031,
       59940.05994006, 60189.81018981, 60439.56043956, 60689.31068931,
       60939.06093906, 61188.81118881, 61438.56143856, 61688.31168831,
       61938.06193806, 62187.81218781, 62437.56243756, 62687.31268731,
       62937.06293706, 63186.81318681, 63436.56343656, 63686.31368631,
       63936.06393606, 64185.81418581, 64435.56443556, 64685.31468531,
       64935.06493506, 65184.81518482, 65434.56543457, 65684.31568432,
       65934.06593407, 66183.81618382, 66433.56643357, 66683.31668332,
       66933.06693307, 67182.81718282, 67432.56743257, 67682.31768232,
       67932.06793207, 68181.81818182, 68431.56843157, 68681.31868132,
       68931.06893107, 69180.81918082, 69430.56943057, 69680.31968032,
       69930.06993007, 70179.82017982, 70429.57042957, 70679.32067932,
       70929.07092907, 71178.82117882, 71428.57142857])

Data: (1)

(distance, event_time_offset)

float64

Å

nan, nan, ..., 8.074, 8.308

σ = nan, nan, ..., 1.462, 1.853

Values:
array([[       nan,        nan, 0.2148344 , ...,        nan,        nan,
               nan],
       [       nan,        nan, 0.21241726, ...,        nan,        nan,
               nan],
       [       nan,        nan, 0.21140654, ...,        nan,        nan,
               nan],
       ...,
       [8.54793577, 8.78012913, 8.36028391, ..., 8.10410374, 7.99302061,
        8.54793577],
       [7.99956531, 8.39549593, 8.81742205, ..., 8.05682364, 8.13086086,
        7.99956531],
       [8.30834448, 8.15007414, 7.88318828, ..., 8.3654067 , 8.07364651,
        8.30834448]], shape=(264, 287))

Variances (σ²):
array([[           nan,            nan, 1.63721776e-04, ...,
                   nan,            nan,            nan],
       [           nan,            nan, 1.42831882e-04, ...,
                   nan,            nan,            nan],
       [           nan,            nan, 1.07851736e-04, ...,
                   nan,            nan,            nan],
       ...,
       [4.82458372e+00, 6.31272347e+00, 3.10166559e+00, ...,
        2.17606846e+00, 1.12793671e+00, 4.82458372e+00],
       [1.10327512e+00, 3.84813613e+00, 6.31678736e+00, ...,
        1.99675485e+00, 2.27031939e+00, 1.10327512e+00],
       [3.43304475e+00, 2.18904901e+00, 1.01319152e-02, ...,
        4.37937313e+00, 2.13640607e+00, 3.43304475e+00]], shape=(264, 287))

[4]:

table.plot()

[4]:

../../_images/user-guide_loki_loki-make-wavelength-lookup-table_6_0.svg

Save to file#

[5]:

# Write to file
table.save_hdf5('loki-wavelength-lookup-table-no-choppers.h5')

Writing type '<class 'NoneType'>' to HDF5 not implemented, skipping.

This Page

Create a wavelength lookup table for LoKI#

Setting up the workflow#

Compute the table#

Save to file#