Create a time-of-flight lookup table for TBL#

[1]:

import scipp as sc
from ess.reduce import time_of_flight

Setting up the workflow#

[2]:

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

wf = time_of_flight.TofLookupTableWorkflow()
wf[time_of_flight.DiskChoppers] = {}
wf[time_of_flight.SourcePosition] = source_position
wf[time_of_flight.NumberOfSimulatedNeutrons] = 200_000  # Increase this number for more reliable results
wf[time_of_flight.SimulationSeed] = 1234
wf[time_of_flight.PulseStride] = 1
wf[time_of_flight.LtotalRange] = sc.scalar(25.0, unit="m"), sc.scalar(35.0, unit="m")
wf[time_of_flight.DistanceResolution] = sc.scalar(0.1, unit="m")
wf[time_of_flight.TimeResolution] = sc.scalar(250.0, unit='us')
wf[time_of_flight.LookupTableRelativeErrorThreshold] = 1.0

Compute the table#

[3]:

table = wf.compute(time_of_flight.TimeOfFlightLookupTable)
table

[3]:
Show/Hide data repr Show/Hide attributes
scipp.DataArray (471.82 KB)
    • distance: 104
    • event_time_offset: 287
    • distance
      (distance)
      float64
      m
      24.85, 24.950, ..., 35.050, 35.150
      Values:
      array([24.85, 24.95, 25.05, 25.15, 25.25, 25.35, 25.45, 25.55, 25.65,
       25.75, 25.85, 25.95, 26.05, 26.15, 26.25, 26.35, 26.45, 26.55,
       26.65, 26.75, 26.85, 26.95, 27.05, 27.15, 27.25, 27.35, 27.45,
       27.55, 27.65, 27.75, 27.85, 27.95, 28.05, 28.15, 28.25, 28.35,
       28.45, 28.55, 28.65, 28.75, 28.85, 28.95, 29.05, 29.15, 29.25,
       29.35, 29.45, 29.55, 29.65, 29.75, 29.85, 29.95, 30.05, 30.15,
       30.25, 30.35, 30.45, 30.55, 30.65, 30.75, 30.85, 30.95, 31.05,
       31.15, 31.25, 31.35, 31.45, 31.55, 31.65, 31.75, 31.85, 31.95,
       32.05, 32.15, 32.25, 32.35, 32.45, 32.55, 32.65, 32.75, 32.85,
       32.95, 33.05, 33.15, 33.25, 33.35, 33.45, 33.55, 33.65, 33.75,
       33.85, 33.95, 34.05, 34.15, 34.25, 34.35, 34.45, 34.55, 34.65,
       34.75, 34.85, 34.95, 35.05, 35.15])
    • distance_resolution
      ()
      float64
      m
      0.10000000000000142
      Values:
      array(0.1)
    • error_threshold
      ()
      float64
      𝟙
      1.0
      Values:
      array(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])
    • pulse_period
      ()
      float64
      µs
      71428.57142857142
      Values:
      array(71428.57142857)
    • pulse_stride
      ()
      int64
      1
      Values:
      array(1)
    • time_resolution
      ()
      float64
      µs
      249.7502497502497
      Values:
      array(249.75024975)
    • (distance, event_time_offset)
      float64
      µs
      6.956e+04, 6.952e+04, ..., 7.404e+04, 7.362e+04
      σ = 880.701, 984.356, ..., 1.782e+04, 1.589e+04
      Values:
      array([[69560.69227517, 69519.76736659, 70140.72590775, ...,
        68867.79296964, 69245.39894307, 69560.69227517],
       [69483.51979216, 69665.53039819, 69844.33662745, ...,
        69102.79413823, 69152.83605128, 69483.51979216],
       [69447.68560121, 69781.89415851, 69880.89456877, ...,
        69063.77534321, 69373.15576621, 69447.68560121],
       ...,
       [73953.842521  , 71394.6337556 , 74652.6583674 , ...,
        74217.36322184, 72782.90594314, 73953.842521  ],
       [73228.1032382 , 74484.65940167, 73837.7481326 , ...,
        72947.25531121, 71983.00467554, 73228.1032382 ],
       [73616.10992809, 73383.30756582, 74560.4227035 , ...,
        71974.3918415 , 74044.16869488, 73616.10992809]], shape=(104, 287))

      Variances (σ²):
      array([[7.75634571e+05, 9.68957205e+05, 8.48803421e+05, ...,
        6.12366551e+05, 6.88986598e+05, 7.75634571e+05],
       [6.56096936e+05, 7.91945952e+05, 8.75153161e+05, ...,
        6.21641713e+05, 6.67760750e+05, 6.56096936e+05],
       [7.12050861e+05, 6.75684190e+05, 5.83136455e+05, ...,
        7.78377530e+05, 6.09796070e+05, 7.12050861e+05],
       ...,
       [2.81005968e+08, 1.11491577e+08, 2.97938852e+08, ...,
        3.28057996e+08, 2.28251537e+08, 2.81005968e+08],
       [2.32721728e+08, 3.09540311e+08, 2.63862250e+08, ...,
        2.49574902e+08, 1.67965222e+08, 2.32721728e+08],
       [2.52585594e+08, 2.24348594e+08, 3.10237939e+08, ...,
        1.92051565e+08, 3.17470085e+08, 2.52585594e+08]], shape=(104, 287))
[4]:

table.plot()

[4]:
../../_images/user-guide_tbl_tbl-make-tof-lookup-table_6_0.svg

Save to file#

[5]:

# Save chopper metadata
# Write to file
table.save_hdf5('TBL-tof-lookup-table-no-choppers.h5')