Cylindrical tallies, negatives fluxes?

[Thomas]

Using estimator = ‘collision’ solves the issue.

I think that, as for spheres detectors, tracklengths calculations for cylindrical detectors are bugged…

See the topic about spheres here :

Question for mesh tallys and cells, very different values

import openmc import numpy as np import pandas as pd import os os.environ[‘OPENMC_CROSS_SECTIONS’] = ‘’ openmc.config[‘cross_sections’] = ‘’ Materials air=openmc.Material(name=‘air’) air.add_element(‘N’,80) air.add_element(‘O’,20) air.set_density(‘g/cm3’,1.3e-3) materials = openmc.Materials([air]) materials.export_to_xml() Geometry Limiting Planes Xm = openmc.XPlane( x0=-300, name=‘X-’, boundary_type=‘vacuum’) Xp = openmc.XPlane( x0=+300, name=‘X+’, boundary_type=‘vacuum’) Ym = …