Index error occurs within the get_XS during continuous energy calculations

[melekderman]

Description:

An index error emerges during continuous energy calculations after the inactive cycles, for example, in the continuous-energy version of the C5G7-TD model (C5CE), static phase 1:

**(mcdc_env) flip1 ~/projects/problems/challenge_problems/07-C5CE-4_phase/static-phase1 1006$ python -m cProfile -o output_1e2.prof input.py --mode=python

  __  __  ____  __ ____   ____
 |  \/  |/ ___|/ /_  _ \ / ___|
 | |\/| | |   /_  / | | | |
 | |  | | |___ / /| |_| | |___
 |_|  |_|\____|// |____/ \____|

           Mode | Python
      Algorithm | History-based
  MPI Processes | 1
 OpenMP Threads | 1
 Now running TNT...

 #     k        GyRad.  k (avg)
 ====  =======  ======  ===================
 1     1.34906   12.27
 2     0.95941   16.70
 3     0.92802   20.42
 4     1.10895   22.34
 5     0.62517   27.32
 6     1.09287   28.71
 7     0.70137   34.20
 8     0.98292   32.01
 9     0.88183   34.07
 10    0.96569   32.04
nuclide["ce_nu_d"][j]: [0. 0. 0. 0. 0.]
E: 2388634.141459218
nuclide["E_nu_d"]: [0. 0. 0. 0. 0.]
nuclide["NE_nu_d"]: 0
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/nfs/stak/users/dermanm/miniconda3/envs/mcdc_env/lib/python3.11/cProfile.py", line 191, in <module>
    main()
  File "/nfs/stak/users/dermanm/miniconda3/envs/mcdc_env/lib/python3.11/cProfile.py", line 180, in main
    runctx(code, globs, None, options.outfile, options.sort)
  File "/nfs/stak/users/dermanm/miniconda3/envs/mcdc_env/lib/python3.11/cProfile.py", line 20, in runctx
    return _pyprofile._Utils(Profile).runctx(statement, globals, locals,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/nfs/stak/users/dermanm/miniconda3/envs/mcdc_env/lib/python3.11/profile.py", line 63, in runctx
    prof.runctx(statement, globals, locals)
  File "/nfs/stak/users/dermanm/miniconda3/envs/mcdc_env/lib/python3.11/cProfile.py", line 101, in runctx
    exec(cmd, globals, locals)
  File "input.py", line 378, in <module>
    mcdc.run()
  File "/nfs/stak/users/dermanm/projects/libraries/MCDC/mcdc/main.py", line 84, in run
    loop_eigenvalue(data_arr, mcdc_arr)
  File "/nfs/stak/users/dermanm/projects/libraries/MCDC/mcdc/loop.py", line 154, in loop_eigenvalue
    loop_source(seed_source, data, mcdc)
  File "/nfs/stak/users/dermanm/projects/libraries/MCDC/mcdc/loop.py", line 360, in loop_source
    exhaust_active_bank(data, mcdc)
  File "/nfs/stak/users/dermanm/projects/libraries/MCDC/mcdc/loop.py", line 257, in exhaust_active_bank
    loop_particle(P_arr, data, mcdc)
  File "/nfs/stak/users/dermanm/projects/libraries/MCDC/mcdc/loop.py", line 497, in loop_particle
    step_particle(P_arr, data, prog)
  File "/nfs/stak/users/dermanm/projects/libraries/MCDC/mcdc/loop.py", line 506, in step_particle
    kernel.move_to_event(P_arr, data, mcdc)
  File "/nfs/stak/users/dermanm/projects/libraries/MCDC/mcdc/kernel.py", line 2413, in move_to_event
    eigenvalue_tally(P_arr, distance, mcdc)
  File "/nfs/stak/users/dermanm/projects/libraries/MCDC/mcdc/kernel.py", line 2132, in eigenvalue_tally
    nu_d = get_nu_group(NU_FISSION_DELAYED, nuclide, E, j)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/nfs/stak/users/dermanm/projects/libraries/MCDC/mcdc/kernel.py", line 3338, in get_nu_group
    return get_XS(
           ^^^^^^^
  File "/nfs/stak/users/dermanm/projects/libraries/MCDC/mcdc/kernel.py", line 3304, in get_XS
    E2 = E_grid[idx + 1]
         ~~~~~~^^^^^^^^^
IndexError: index 5 is out of bounds for axis 0 with size 5**

Observations:

• When checking the values of the arguments passed to the get_XS function at this energy, I observed that the values (data, E_grid, and NE) other than E, are zero.

07-C5CE-4_phase/static-phase1:

nuclide["ce_nu_d"][j]: [0. 0. 0. 0. 0.]
E: 2388634.141459218
nuclide["E_nu_d"]: [0. 0. 0. 0. 0.]
nuclide["NE_nu_d"]: 0

07-C5CE-4_phase/static-phase2:

nuclide["ce_nu_d"][j]: [0. 0. 0. 0. 0.]
E: 359140.4050425384
nuclide["E_nu_d"]: [0. 0. 0. 0. 0.]
nuclide["NE_nu_d"]: 0

07-C5CE-4_phase/static-phase3:

nuclide["ce_nu_d"][j]: [0. 0. 0. 0. 0.]
E: 359140.4050425384
nuclide["E_nu_d"]: [0. 0. 0. 0. 0.]
nuclide["NE_nu_d"]: 0

07-C5CE-4_phase/static-phase4:

nuclide["ce_nu_d"][j]: [0. 0. 0. 0. 0.]
E: 1803386.4079506723
nuclide["E_nu_d"]: [0. 0. 0. 0. 0.]
nuclide["NE_nu_d"]: 0

• For other energies calculated up to this point, I verified that these argument values were not 0, for example:

nuclide["ce_nu_d"][group]: [0.00105286 0.00110932 0.00110932 0.00059784 0.00059784]
E: 0.10319329728921613
nuclide["E_nu_d"]: [1.e-05 5.e+04 4.e+06 7.e+06 3.e+07]
nuclide["NE_nu_d"]: 5

nuclide["ce_nu_d"][group]: [0.00055487 0.00058463 0.00058463 0.00031507 0.00031507]
E: 39.419109137797946
nuclide["E_nu_d"]: [1.e-05 5.e+04 4.e+06 7.e+06 3.e+07]
nuclide["NE_nu_d"]: 5

Identified issues to be resolved:

1) Why are the data, E_grid, and NE values 0 for these specific energy values?
2) When the NE=0 for some reason, the binary_search_with_length function in algorithm.py reduces the index value by 1 and it causes an index error. (The if length == 0: right = len(grid) - 1 statement in binary_search_with_length function within algorithym.py might require review.)