echidna.calc package

Submodules

echidna.calc.constants module

echidna.calc.decay module

Double beta decay utility converter

Provides a useful tool for converting between different double beta dacay parameters.

class echidna.calc.decay.DBIsotope(name, atm_weight_iso, atm_weight_nat, abundance, phase_space, matrix_element, loading=None, outer_radius=None, scint_density=None)[source]

Bases: object

Class which calculates expected counts for a DBD isotope
over a given experiment livetime.
Parameters:
  • name (string) – Name of the isotope.
  • atm_weight_iso (float) – Atomic weight of isotope in g/mol.
  • atm_weight_nat (float) – Atomic weight of natural element in g/mol.
  • abundance (float) – Natural abundance of isotope with 0 to 1 equivalent to 0% to 100%.
  • phase_space (float) – Phase space of the isotope.
  • matrix_element (float) – Matrix element of the isotope.
  • loading (float, optional) – Loading of isotope with 0 to 1 equivalent to 0% to 100%. Default is stored in echidna.calc.constants
  • scint_density (float, optional) – Density of liquid scintillator in kg/mm^3. Default is stored in echidna.calc.constants
  • outer_radius (float, optional) – Radius of outer container containing fiducial volume, e.g. AV, in mm. Default is stored in echidna.calc.constants
Variables:
  • _name (string) – Name of the isotope.
  • _atm_weight_iso (float) – Atomic weight of isotope in g/mol.
  • _atm_weight_nat (float) – Atomic weight of natural element in g/mol.
  • _abundance (float) – Natural abundance of isotope with 0 to 1 equivalent to 0% to 100%.
  • _phase_space (float) – Phase space of the isotope.
  • _matrix_element (float) – Matrix element of the isotope.
  • _loading (float) – Loading of isotope with 0 to 1 equivalent to 0% to 100%. Default is stored in echidna.calc.constants
  • _scint_density (float) – Density of liquid scintillator in kg/mm^3. Default is stored in echidna.calc.constants
  • _outer_radius (float) – Radius of outer container containing fiducial volume, e.g. AV, in mm. Default is stored in echidna.calc.constants
Raises:
  • ValueError – If abundance is < 0. or > 1.
  • ValueError – If outer_radius is negative or zero.
activity_to_counts(activity, livetime=5.0)[source]

Converts activity to number of counts, assuming constant activity.

Parameters:
  • activity (float) – Initial activity of the isotope in \(years^{-1}\).
  • livetime (float, optional) – Amount of years of data taking. Default is 5 years.
Raises:

ValueError – If livetime is not positive and non-zero.
Returns:

Number of counts.
Return type:

float
activity_to_half_life(activity, n_atoms=None)[source]

Calculates the half-life of an isotope with a given activity and number of atoms.

Parameters:
  • activity (float) – Activity of the isotope in
  • n_atoms (float, optional) – Number of atoms of an isotope.
Returns:

Half-life in years.
Return type:

float
counts_to_activity(counts, livetime=5.0)[source]

Converts counts to activity, assuming constant activity.

Parameters:
  • counts (float) – Number of counts.
  • livetime (float, optional) – Amount of years of data taking. Default is 5 years.
Raises:

ValueError – If livetime is not positive and non-zero.
Returns:

Activity of the isotope in \(years^{-1}\).
Return type:

float
counts_to_eff_mass(counts, n_atoms=None, livetime=5.0)[source]

Converts from signal counts to effective majorana mass.

Parameters:
  • counts (float) – Number of signal counts within the livetime specified.
  • n_atoms (float, optional) – Number of isotope atoms/nuclei that could potentially decay to produce signal.
  • livetime (float, optional) – Amount of years of data taking. Default is 5 years.
Raises:

ValueError – If livetime is not positive and non-zero.
Returns:

Effective majorana mass in eV.
Return type:

float
counts_to_half_life(counts, n_atoms=None, livetime=5.0)[source]

Converts from signal count to isotope’s half-life.

Parameters:
  • count (float) – Number of signal counts within the livetime specified.
  • n_atoms (float, optional) – Number of isotope atoms/nuclei that could potentially decay to produce signal.
  • livetime (float, optional) – Amount of years of data taking. Default is 5 years.
Raises:

ValueError – If livetime is not positive and non-zero.
Returns:

Isotope’s \(0\nu2\beta\) half-life in years.
Return type:

float
eff_mass_to_counts(eff_mass, n_atoms=None, livetime=5.0)[source]

Converts from effective majorana mass to signal counts.

Parameters:
  • eff_mass (float) – Effective majorana mass in eV.
  • n_atoms (float, optional) – Number of isotope atoms/nuclei that could potentially decay to produce signal.
  • livetime (float, optional) – Amount of years of data taking. Default is 5 years.
Raises:
  • ValueError – If effective mass is not positive and non-zero.
  • ValueError – If arg:livetime is not positive and non-zero.
Returns:

Expected number of signal counts within the livetime specified.
Return type:

float
eff_mass_to_half_life(eff_mass)[source]

Converts from effective majorana mass to \(0\nu2\beta\) half-life.

Parameters:eff_mass (float) – Effective majorana mass, in eV.
Raises:ValueError – If effective mass is not positive and non-zero.
Returns:\(0\nu2\beta\) half-life, in years.
Return type:float
get_n_atoms(loading=None, scint_density=None, target_mass=None, scint_mass=None, outer_radius=None)[source]

Calculates the number of atoms of the double-beta isotope.

Set up to follow the full (SNO+-specific) calculation as per SNO+-doc-1728v2 but can look at other scenarios/detectors by overriding the default args.

Warning

All args default to SNO+ specific values!

Parameters:
  • loading (float, optional) – Loading of isotope with 0 to 1 equivalent to 0% to 100%. Default is stored as a class variable.
  • scint_density (float, optional) – Density of liquid scintillator in kg/mm^3. Default is stored as a class variable.
  • target_mass (float, optional) – Target mass in kg. Calculates a value by default.
  • scint_mass (float, optional) – Mass of scintillator in kg. Calculates a value by default.
  • outer_radius (float, optional) – Radius of outer container containing fiducial volume, e.g. AV, in mm. Default is stored as a class variable.
Raises:
  • ValueError – If loading is not between zero and 1.
  • ValueError – If outer_radius is negative or zero.
Returns:

Number of atoms.
Return type:

float
half_life_to_activity(half_life, n_atoms=None)[source]
Calculates the activity for an isotope with a given half-life
and number of atoms.
Parameters:
  • half_life (float) – Half-life of an isotope in years.
  • n_atoms (float, optional) – Number of atoms of an isotope.
Returns:

Activity in decays per year.
Return type:

float
half_life_to_counts(half_life, n_atoms=None, livetime=5.0)[source]

Converts from isotope’s half-life to signal counts.

Parameters:
  • half_life (float) – Isotope’s \(0\nu2\beta\) half-life in years.
  • n_atoms (float, optional) – Number of isotope atoms/nuclei that could potentially decay to produce signal.
  • livetime (float, optional) – Amount of years of data taking. Default is 5 years.
Raises:

ValueError – If livetime is not positive and non-zero.
Returns:

Expected number of counts.
Return type:

float
half_life_to_eff_mass(half_life)[source]
Converts from \(0\nu2\beta\) half-life to effective
majorana mass.
Parameters:half_life (float) – \(0\nu2\beta\) half-life, in years.
Returns:Effective majorana mass, in eV.
Return type:float
echidna.calc.decay.test(args)[source]

Test function to show agreement with Andy’s numbers.

Parameters:args (dict) – Command line arguments from argparse

Module contents