pleiades.utils.units module

class pleiades.utils.units.TimeUnitOptions(value)[source]

Bases: str, Enum

s = 's'
ms = 'ms'
us = 'us'
ns = 'ns'
ps = 'ps'
class pleiades.utils.units.EnergyUnitOptions(value)[source]

Bases: str, Enum

meV = 'meV'
eV = 'eV'
keV = 'keV'
MeV = 'MeV'
GeV = 'GeV'
J = 'J'
class pleiades.utils.units.CrossSectionUnitOptions(value)[source]

Bases: str, Enum

barn = 'barn'
millibarn = 'millibarn'
microbarn = 'microbarn'
cm2 = 'cm^2'
class pleiades.utils.units.DistanceUnitOptions(value)[source]

Bases: str, Enum

cm = 'cm'
nm = 'nm'
pm = 'pm'
m = 'm'
angstrom = 'angstrom'
pleiades.utils.units.convert_time_units(from_unit, to_unit)[source]

Convert time from one unit to another unit based on TimeUnitOptions options

Parameters:
Returns:

Time in the new unit.

Return type:

float

pleiades.utils.units.convert_distance_units(from_unit, to_unit)[source]

Convert distance from one unit to another unit based on DistanceUnitOptions options

Parameters:
Returns:

distance in the new unit.

Return type:

float

pleiades.utils.units.convert_to_energy(from_unit, to_unit)[source]

Convert energy from one unit to another unit based on EnergyUnitOptions options

Parameters:
Returns:

Energy in the new unit.

Return type:

float

pleiades.utils.units.convert_to_cross_section(from_unit, to_unit)[source]

Convert cross section from one unit to another unit based on CrossSectionUnitOptions options

Parameters:
Returns:

Cross section in the new unit.

Return type:

float

pleiades.utils.units.convert_array_from_time_to_lambda(time_array: ndarray, time_unit: TimeUnitOptions, distance_source_detector: float, distance_source_detector_unit: DistanceUnitOptions, detector_offset: float, detector_offset_unit: DistanceUnitOptions, lambda_unit: DistanceUnitOptions) → ndarray[source]

Convert an array of time values to wavelength values.

Parameters:

  • time_array (np.ndarray) – Array of time values.

  • time_unit (TimeUnitOptions) – Unit of the input time.

  • distance_source_detector (float) – Distance from the source to the detector.

  • distance_source_detector_unit (DistanceUnitOptions) – Unit of the distance.

  • detector_offset (float) – Offset of the detector.

  • detector_offset_unit (DistanceUnitOptions) – Unit of the offset.

  • lambda_unit (DistanceUnitOptions) – Unit of the output wavelength.

This is using the formula: lambda_m = h/(m_n * distance_source_detector_m) * (time_array_s + detector_offset_s)

Returns:

Array of wavelength values.

Return type:

np.ndarray

pleiades.utils.units.convert_array_from_time_to_energy(time_array: ndarray, time_unit: TimeUnitOptions, distance_source_detector: float, distance_source_detector_unit: DistanceUnitOptions, detector_offset: float, detector_offset_unit: DistanceUnitOptions, energy_unit: EnergyUnitOptions) → ndarray[source]

Convert an array of time values to energy values.

Parameters:

  • time_array (np.ndarray) – Array of time values.

  • time_unit (TimeUnitOptions) – Unit of the input time.

  • distance_source_detector (float) – Distance from the source to the detector.

  • distance_source_detector_unit (DistanceUnitOptions) – Unit of the distance.

  • detector_offset (float) – Offset of the detector.

  • detector_offset_unit (DistanceUnitOptions) – Unit of the offset.

  • energy_unit (EnergyUnitOptions) – Unit of the output energy.

this is using the formula: E_ev = 1/2 m_n (L/t_tof)^2 / electron_volt

where

t_tof = L/ v (L is the distance from the source to the detector in m, v is the velocity of the neutron in m/s). E is the kinetic energy of the neutron in eV.

Returns:

Array of energy values.

Return type:

np.ndarray

pleiades.utils.units.calculate_number_density(material_density_g_cm3: float, thickness_mm: float, atomic_mass_amu: float) → float[source]

Convert material properties to number density (atoms/barn).

Migrated from legacy/pleiades_old/simData.py for use in multi-isotope INP generation.

Parameters:

  • material_density_g_cm3 – Material density in g/cm³

  • thickness_mm – Sample thickness in mm

  • atomic_mass_amu – Atomic mass in amu

Returns:

Number density in atoms/barn (areal density)

Return type:

float

Example

>>> # For Hafnium sample: density=13.31 g/cm³, thickness=5mm, mass=178.49 amu
>>> density = calculate_number_density(13.31, 5.0, 178.49)
>>> print(f"Number density: {density:.6e} atoms/barn")

Note

This calculation uses the same formula as the legacy code: areal_density = thickness * density * AVOGADRO / atomic_mass / CM2_TO_BARN

TODO: Future enhancement - auto-retrieve material density from element database