unzhakov
0c5c53688d
Add implementation for the basic set of spectrum components: Primary ------- - Phase Space - Fermi Function Corrections ----------- - Atomic: - Screening - Atomic exchange - E/M and finite size: - Finite nucleus size and charge distribution - Radiative
45 lines
1.1 KiB
Python
45 lines
1.1 KiB
Python
import numpy as np
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from beta_spectrum.constants import ALPHA
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from beta_spectrum.base import SpectrumComponent
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from beta_spectrum.utils import nuclear_radius
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class FiniteSizeL0(SpectrumComponent):
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"""
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Finite nuclear size correction L0(W)
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Implements low-Z expansion (Hayen et al.)
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Includes (1 + gamma)/2 prefactor
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"""
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def __init__(self, Z: int, A: int):
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self.Z = Z
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self.A = A
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self.R = nuclear_radius(A)
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self.alphaZ = ALPHA * Z
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self.gamma = np.sqrt(1 - self.alphaZ**2)
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# beta-minus decay
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self.sign = -1
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def __call__(self, W: np.ndarray) -> np.ndarray:
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# Terms from expansion
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term1 = self.sign * self.alphaZ * W * self.R
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term2 = (13 / 60) * self.alphaZ**2
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term3 = -0.5 * (self.alphaZ * self.R) / W
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return 1 + term1 + term2 + term3
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class ChargeDistributionU(SpectrumComponent):
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def __init__(self, Z: int, A: int):
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self.Z = Z
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self.R = nuclear_radius(A)
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self.alphaZ = ALPHA * Z
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def __call__(self, W: np.ndarray) -> np.ndarray:
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return 1.0 + (1 / 5) * (self.alphaZ * W * self.R) ** 2
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