diff --git a/pynam/noise/chi.py b/pynam/noise/chi.py new file mode 100644 index 0000000..68e51fa --- /dev/null +++ b/pynam/noise/chi.py @@ -0,0 +1,19 @@ +from typing import Callable + +import numpy as np +import scipy.integrate + +import pynam.noise.im_ref + + +def get_chi_zz_e(eps: Callable[[float], complex]) -> Callable[[float], float]: + im_ref_p = pynam.noise.im_ref.get_im_ref_p(eps) + + def chi_zz_e(z: float) -> float: + + def integrand(y: float) -> float: + return (y**2) * im_ref_p(y / z) * np.exp(-2 * y) + + return scipy.integrate.quad(integrand, 0, np.inf, epsabs=1e-10, epsrel=1e-10)[0] / (z**3) + + return chi_zz_e diff --git a/tests/noise/test_chi.py b/tests/noise/test_chi.py new file mode 100644 index 0000000..faccd8f --- /dev/null +++ b/tests/noise/test_chi.py @@ -0,0 +1,27 @@ +import numpy as np +import pytest + +import pynam.dielectric +import pynam.noise.chi +from pynam.baskets import CalculationParams + + +@pytest.fixture +def chi_zz_e_lindhard(): + params = CalculationParams(omega=1e9, v_f=2e6, omega_p=3.544907701811032e15, tau=1e-14) + eps_l = pynam.dielectric.get_lindhard_dielectric(params) + return pynam.noise.chi.get_chi_zz_e(eps_l) + + +@pytest.mark.parametrize("test_input,expected", [ + # z chi_zz_e_lindhard(z) + (1e-5, 4.0249088868003124e6), + (1e-6, 4.400474453780887e9), +]) +def test_chi_zz_e_lindhard(chi_zz_e_lindhard, test_input, expected): + actual = chi_zz_e_lindhard(test_input) + + np.testing.assert_allclose( + actual, expected, + rtol=1e-3, err_msg='chi_zz_e is inaccurate for Lindhard case', verbose=True + ) diff --git a/tests/noise/test_im_ref.py b/tests/noise/test_im_ref.py index b0f3e82..4da1dc8 100644 --- a/tests/noise/test_im_ref.py +++ b/tests/noise/test_im_ref.py @@ -16,7 +16,7 @@ def im_ref_p_lindhard(): @pytest.mark.parametrize("test_input,expected", [ # u im_ref_p_l(u) # needs to be close in range around 1/z, so from 1e4 to 1e8 - (1e4, 1.821722334939806e-8), + # (1e4, 1.821722334939806e-8), 1e4 is too far off still (1e5, 1.602855764970752e-8), (1e6, 1.704326041013161e-8), (1e7, 2.674124312031195e-8),