Esempio n. 1
0
class nuVeto(object):
    """Class for computing the neutrino passing fraction i.e. (1-(Veto probability))"""
    def __init__(self,
                 costh,
                 pmodel=(pm.HillasGaisser2012, 'H3a'),
                 hadr='SIBYLL2.3c',
                 barr_mods=(),
                 depth=1950 * Units.m,
                 density=('CORSIKA', ('SouthPole', 'December')),
                 debug_level=1):
        """Initializes the nuVeto object for a particular costheta, CR Flux,
        hadronic model, barr parameters, and depth

        Note:
            A separate MCEq instance needs to be created for each
            combination of __init__'s arguments. To access pmodel and hadr,
            use mceq.pm_params and mceq.yields_params
        Args:
            costh (float): Cos(theta), the cosine of the neutrino zenith at the detector
            pmodel (tuple(CR model class, arguments)): CR Flux
            hadr (str): hadronic interaction model
            barr_mods: barr parameters
            depth (float): the depth at which the veto probability is computed below the ice
        """
        self.costh = costh
        self.pmodel = pmodel
        self.geom = Geometry(depth)
        theta = np.degrees(np.arccos(self.geom.cos_theta_eff(self.costh)))
        if density[0] == 'MSIS00_IC':
            print('Passing "MSIS00_IC" assumes IceCube-centered coordinates, '
                  'which obviates the depth used here. Switching to "MSIS00" '
                  'for identical results.')
            density = ('MSIS00', density[1])

        config.debug_level = debug_level
        # config.enable_em = False
        config.enable_muon_energy_loss = False
        config.return_as = 'total energy'
        config.adv_set['allowed_projectiles'] = [
            2212, 2112, 211, -211, 321, -321, 130, -2212, -2112
        ]  #, 11, 22]
        config.ctau = 2.5
        self.mceq = MCEqRun(
            # provide the string of the interaction model
            interaction_model=hadr,
            # primary cosmic ray flux model
            # support a tuple (primary model class (not instance!), arguments)
            primary_model=pmodel,
            # zenith angle \theta in degrees, measured positively from vertical direction at surface
            theta_deg=theta,
            # atmospheric density model
            density_model=density)

        if len(barr_mods) > 0:
            for barr_mod in barr_mods:
                # Modify proton-air -> mod[0]
                self.mceq.set_mod_pprod(2212, BARR[barr_mod[0]].pdg, barr_unc,
                                        barr_mod)
            # Populate the modifications to the matrices by re-filling the interaction matrix
            self.mceq.regenerate_matrices(skip_decay_matrix=True)

        X_vec = np.logspace(np.log10(2e-3),
                            np.log10(self.mceq.density_model.max_X), 12)
        self.dX_vec = np.diff(X_vec)
        self.X_vec = 10**centers(np.log10(X_vec))

    @staticmethod
    def categ_to_mothers(categ, daughter):
        """Get the parents for this category"""
        rcharge = '-' if 'bar' in daughter else '+'
        lcharge = '+' if 'bar' in daughter else '-'
        rbar = 'bar' if 'bar' in daughter else ''
        lbar = '' if 'bar' in daughter else 'bar'
        if categ == 'conv':
            mothers = ['pi' + rcharge, 'K' + rcharge, 'K_L0']
            if 'nu_tau' in daughter:
                mothers = []
            elif 'nu_e' in daughter:
                mothers.extend(['K_S0', 'mu' + rcharge])
            elif 'nu_mu' in daughter:
                mothers.extend(['mu' + lcharge])
        elif categ == 'pr':
            if 'nu_tau' in daughter:
                mothers = ['D' + rcharge, 'D_s' + rcharge]
            else:
                mothers = ['D' + rcharge, 'D_s' + rcharge, 'D' + rbar + '0'
                           ]  #, 'Lambda'+lbar+'0']#, 'Lambda_c'+rcharge]
        elif categ == 'total':
            mothers = nuVeto.categ_to_mothers(
                'conv', daughter) + nuVeto.categ_to_mothers('pr', daughter)
        else:
            mothers = [
                categ,
            ]
        return mothers

    @staticmethod
    def esamp(enu, accuracy):
        """ returns the sampling of parent energies for a given enu
        """
        # TODO: replace 1e8 with MMC-prpl interpolated bounds
        return np.logspace(np.log10(enu), np.log10(enu + 1e8),
                           int(1000 * accuracy))

    @staticmethod
    def projectiles():
        """Get allowed pimaries"""
        pdg_ids = config.adv_set['allowed_projectiles']
        namer = ParticleProperties.modtab.pdg2modname
        allowed = []
        for pdg_id in pdg_ids:
            allowed.append(namer[pdg_id])
            try:
                allowed.append(namer[-pdg_id])
            except KeyError:
                continue
        return allowed

    @staticmethod
    def nbody(fpath, esamp, enu, fn, l_ice):
        with np.load(fpath) as dfile:
            xmus = centers(dfile['xedges'])
            xnus = np.concatenate([xmus, [1]])
            vals = np.nan_to_num(dfile['histograms'])

            ddec = interpolate.RegularGridInterpolator((xnus, xmus),
                                                       vals,
                                                       bounds_error=False,
                                                       fill_value=None)
            emu_mat = xmus[:, None] * esamp[None, :] * Units.GeV
            pmu_mat = ddec(np.stack(np.meshgrid(enu / esamp, xmus), axis=-1))
            reaching = 1 - np.sum(pmu_mat * fn.prpl(
                np.stack([emu_mat, np.ones(emu_mat.shape) * l_ice], axis=-1)),
                                  axis=0)
            reaching[reaching < 0.] = 0.
            return reaching

    @staticmethod
    @lru_cache(2**12)
    def psib(l_ice, mother, enu, accuracy, prpl):
        """ returns the suppression factor due to the sibling muon
        """
        esamp = nuVeto.esamp(enu, accuracy)
        fn = MuonProb(prpl)
        if mother in ['D0', 'D0-bar']:
            reaching = nuVeto.nbody(
                resource_filename('nuVeto',
                                  'data/decay_distributions/D0_numu.npz'),
                esamp, enu, fn, l_ice)
        elif mother in ['D+', 'D-']:
            reaching = nuVeto.nbody(
                resource_filename('nuVeto',
                                  'data/decay_distributions/D+_numu.npz'),
                esamp, enu, fn, l_ice)
        elif mother in ['Ds+', 'Ds-']:
            reaching = nuVeto.nbody(
                resource_filename('nuVeto',
                                  'data/decay_distributions/Ds_numu.npz'),
                esamp, enu, fn, l_ice)
        elif mother == 'K0L':
            reaching = nuVeto.nbody(
                resource_filename('nuVeto',
                                  'data/decay_distributions/K0L_numu.npz'),
                esamp, enu, fn, l_ice)
        else:
            # Assuming muon energy is E_parent - E_nu
            reaching = 1. - fn.prpl(
                list(zip((esamp - enu) * Units.GeV, [l_ice] * len(esamp))))
        return reaching

    @lru_cache(maxsize=2**12)
    def get_dNdEE(self, mother, daughter):
        """Differential parent-->neutrino (mother--daughter) yield"""
        ihijo = 20
        e_grid = self.mceq.e_grid
        delta = self.mceq.e_widths
        x_range = e_grid[ihijo] / e_grid
        rr = ParticleProperties.rr(mother, daughter)
        dNdEE_edge = ParticleProperties.br_2body(mother, daughter) / (1 - rr)
        dN_mat = self.mceq._decays.get_matrix(
            (ParticleProperties.pdg_id[mother], 0),
            (ParticleProperties.pdg_id[daughter], 0))
        dNdEE = dN_mat[ihijo] * e_grid / delta
        logx = np.log10(x_range)
        logx_width = -np.diff(logx)[0]
        good = (logx + logx_width / 2 < np.log10(1 - rr)) & (x_range >= 5.e-2)

        x_low = x_range[x_range < 5e-2]
        dNdEE_low = np.array([dNdEE[good][-1]] * x_low.size)
        dNdEE_interp = lambda x_: interpolate.pchip(
            np.concatenate([[1 - rr], x_range[good], x_low])[::-1],
            np.concatenate([[dNdEE_edge], dNdEE[good], dNdEE_low])[::-1],
            extrapolate=True)(x_) * np.heaviside(1 - rr - x_, 1)
        return x_range, dNdEE, dNdEE_interp

    @lru_cache(maxsize=2**12)
    def grid_sol(self, ecr=None, particle=None):
        """MCEq grid solution for \\frac{dN_{CR,p}}_{dE_p}"""
        if ecr is not None:
            self.mceq.set_single_primary_particle(ecr, particle)
        else:
            self.mceq.set_primary_model(*self.pmodel)
        self.mceq.solve(int_grid=self.X_vec, grid_var="X")
        return self.mceq.grid_sol

    @lru_cache(maxsize=2**12)
    def nmu(self, ecr, particle, prpl='ice_allm97_step_1'):
        """Poisson probability of getting no muons"""
        grid_sol = self.grid_sol(ecr, particle)
        l_ice = self.geom.overburden(self.costh)
        mu = np.abs(self.get_solution('mu-', grid_sol)) + np.abs(
            self.get_solution(
                'mu+', grid_sol))  # np.abs hack to prevent negative fluxes
        fn = MuonProb(prpl)
        coords = list(
            zip(self.mceq.e_grid * Units.GeV, [l_ice] * len(self.mceq.e_grid)))
        ### DEBUG ###
        # if np.trapz(mu*fn.prpl(coords)*self.mceq.e_grid, np.log(self.mceq.e_grid)) < 0:
        #     import pdb
        #     pdb.set_trace()
        ###
        return np.trapz(mu * fn.prpl(coords) * self.mceq.e_grid,
                        np.log(self.mceq.e_grid))

    @lru_cache(maxsize=2**12)
    def get_rescale_phi(self, mother, ecr=None, particle=None):
        """Flux of the mother at all heights"""
        grid_sol = self.grid_sol(
            ecr, particle
        )  # MCEq solution (fluxes tabulated as a function of height)
        dX = self.dX_vec * Units.gr / Units.cm**2
        rho = self.mceq.density_model.X2rho(
            self.X_vec) * Units.gr / Units.cm**3
        inv_decay_length_array = (
            ParticleProperties.mass_dict[mother] /
            (self.mceq.e_grid[:, None] * Units.GeV)) / (
                ParticleProperties.lifetime_dict[mother] * rho[None, :])
        rescale_phi = dX[None, :] * inv_decay_length_array * self.get_solution(
            mother, grid_sol, grid_idx=False).T
        return rescale_phi

    def get_integrand(self,
                      categ,
                      daughter,
                      enu,
                      accuracy,
                      prpl,
                      ecr=None,
                      particle=None):
        """flux*yield"""
        esamp = self.esamp(enu, accuracy)
        mothers = self.categ_to_mothers(categ, daughter)
        nums = np.zeros((len(esamp), len(self.X_vec)))
        dens = np.zeros((len(esamp), len(self.X_vec)))
        for mother in mothers:
            dNdEE = self.get_dNdEE(mother, daughter)[-1]
            rescale_phi = self.get_rescale_phi(mother, ecr, particle)
            # DEBUG
            # from matplotlib import pyplot as plt
            # plt.plot(np.log(self.mceq.e_grid[rescale_phi[:,0]>0]),
            #          np.log(rescale_phi[:,0][rescale_phi[:,0]>0]))
            # rescale_phi = np.array([interpolate.interp1d(self.mceq.e_grid, rescale_phi[:,i], kind='quadratic', bounds_error=False, fill_value=0)(esamp) for i in range(rescale_phi.shape[1])]).T
            ###
            # TODO: optimize to only run when esamp[0] is non-zero
            rescale_phi = np.exp(
                np.array([
                    interpolate.interp1d(
                        np.log(self.mceq.e_grid[rescale_phi[:, i] > 0]),
                        np.log(rescale_phi[:, i][rescale_phi[:, i] > 0]),
                        kind='quadratic',
                        bounds_error=False,
                        fill_value=-np.inf)(np.log(esamp))
                    if np.count_nonzero(rescale_phi[:, i] > 0) > 2 else [
                        -np.inf,
                    ] * esamp.shape[0] for i in range(rescale_phi.shape[1])
                ])).T
            # DEBUG
            # print rescale_phi.min(), rescale_phi.max()
            # print np.log(esamp)
            # plt.plot(np.log(esamp),
            #          np.log(rescale_phi[:,0]), label='intp')
            # plt.legend()
            # import pdb
            # pdb.set_trace()
            ###
            if 'nu_mu' in daughter:
                # muon accompanies nu_mu only
                pnmsib = self.psib(self.geom.overburden(self.costh), mother,
                                   enu, accuracy, prpl)
            else:
                pnmsib = np.ones(len(esamp))
            dnde = dNdEE(enu / esamp) / esamp
            nums += (dnde * pnmsib)[:, None] * rescale_phi
            dens += (dnde)[:, None] * rescale_phi

        return nums, dens

    def get_solution(self, particle_name, grid_sol, mag=0., grid_idx=None):
        """Retrieves solution of the calculation on the energy grid.

        Args:
          particle_name (str): The name of the particle such, e.g.
            ``total_mu+`` for the total flux spectrum of positive muons or
            ``pr_antinumu`` for the flux spectrum of prompt anti muon neutrinos
          mag (float, optional): 'magnification factor': the solution is
            multiplied by ``sol`` :math:`= \\Phi \\cdot E^{mag}`
          grid_idx (int, optional): if the integrator has been configured to save
            intermediate solutions on a depth grid, then ``grid_idx`` specifies
            the index of the depth grid for which the solution is retrieved. If
            not specified the flux at the surface is returned
          integrate (bool, optional): return averge particle number instead of
          flux (multiply by bin width)

        Returns:
          (numpy.array): flux of particles on energy grid :attr:`e_grid`
        """

        # MCEq index conversion
        ref = self.mceq.pman.pname2pref
        p_pdg = ParticleProperties.pdg_id[particle_name]
        reduce_res = True

        if grid_idx is None:  # Surface only case
            sol = np.array([grid_sol[-1]])
            xv = np.array([self.X_vec[-1]])
        elif isinstance(grid_idx,
                        bool) and not grid_idx:  # Whole solution case
            sol = np.asarray(grid_sol)
            xv = np.asarray(self.X_vec)
            reduce_res = False
        elif grid_idx >= len(self.mceq.grid_sol):  # Surface only case
            sol = np.array([grid_sol[-1]])
            xv = np.array([self.X_vec[-1]])
        else:  # Particular height case
            sol = np.array([grid_sol[grid_idx]])
            xv = np.array([self.X_vec[grid_idx]])

        # MCEq solution for particle
        direct = sol[:, ref[particle_name].lidx:ref[particle_name].uidx]
        res = np.zeros(direct.shape)
        rho_air = 1. / self.mceq.density_model.r_X2rho(xv)

        # meson decay length
        decayl = ((self.mceq.e_grid * Units.GeV) /
                  ParticleProperties.mass_dict[particle_name] *
                  ParticleProperties.lifetime_dict[particle_name] / Units.cm)

        # number of targets per cm2
        ndens = rho_air * Units.Na / Units.mol_air
        sec = self.mceq.pman[p_pdg]
        prim2mceq = {
            'p+-bar': 'pbar-',
            'n0-bar': 'nbar0',
            'D0-bar': 'Dbar0',
            'Lambda0-bar': 'Lambdabar0'
        }
        for prim in self.projectiles():
            if prim in prim2mceq:
                _ = prim2mceq[prim]
            else:
                _ = prim
            prim_flux = sol[:, ref[_].lidx:ref[_].uidx]
            proj = self.mceq.pman[ParticleProperties.pdg_id[prim]]
            prim_xs = proj.inel_cross_section()
            try:
                int_yields = proj.hadr_yields[sec]
                res += np.sum(int_yields[None, :, :] * prim_flux[:, None, :] *
                              prim_xs[None, None, :] * ndens[:, None, None],
                              axis=2)
            except KeyError as e:
                continue

        res *= decayl[None, :]
        # combine with direct
        res[direct != 0] = direct[direct != 0]

        if particle_name[:-1] == 'mu':
            for _ in ['k_' + particle_name, 'pi_' + particle_name]:
                res += sol[:, ref[_ + '_l'].lidx:ref[_ + '_l'].uidx]
                res += sol[:, ref[_ + '_r'].lidx:ref[_ + '_r'].uidx]

        res *= self.mceq.e_grid[None, :]**mag

        if reduce_res:
            res = res[0]
        return res

    def get_fluxes(self,
                   enu,
                   kind='conv nu_mu',
                   accuracy=3.5,
                   prpl='ice_allm97_step_1',
                   corr_only=False):
        """Returns the flux and passing fraction
        for a particular neutrino energy, flux, and p_light
        """
        # prpl = probability of reaching * probability of light
        # prpl -> None ==> median for muon reaching
        categ, daughter = kind.split()

        esamp = self.esamp(enu, accuracy)

        # Correlated only (no need for the unified calculation here) [really just for testing]
        passed = 0
        total = 0
        if corr_only:
            # sum performs the dX integral
            nums, dens = self.get_integrand(categ, daughter, enu, accuracy,
                                            prpl)
            num = np.sum(nums, axis=1)
            den = np.sum(dens, axis=1)
            passed = integrate.trapz(num, esamp)
            total = integrate.trapz(den, esamp)
            return passed, total

        pmodel = self.pmodel[0](self.pmodel[1])

        #loop over primary particles
        for particle in pmodel.nucleus_ids:
            # A continuous input energy range is allowed between
            # :math:`50*A~ \\text{GeV} < E_\\text{nucleus} < 10^{10}*A \\text{GeV}`.

            # ecrs --> Energy of cosmic ray primaries
            # amu --> atomic mass of primary

            # evaluation points in E_CR
            ecrs = amu(particle) * np.logspace(2, 10, int(10 * accuracy))

            # pnm --> probability of no muon (just a poisson probability)
            nmu = [self.nmu(ecr, particle, prpl) for ecr in ecrs]

            # nmufn --> fine grid interpolation of pnm
            nmufn = interpolate.interp1d(ecrs,
                                         nmu,
                                         kind='linear',
                                         assume_sorted=True,
                                         bounds_error=False,
                                         fill_value=(0, np.nan))
            # nums --> numerator
            nums = []
            # dens --> denominator
            dens = []
            # istart --> integration starting point, the lowest energy index for the integral
            istart = max(0, np.argmax(ecrs > enu) - 1)
            for ecr in ecrs[istart:]:  # integral in primary energy (E_CR)
                # cr_flux --> cosmic ray flux
                # phim2 --> units of flux * m^2 (look it up in the units)
                cr_flux = pmodel.nucleus_flux(particle,
                                              ecr.item()) * Units.phim2
                # poisson exp(-Nmu) [last term in eq 12]
                pnmarr = np.exp(-nmufn(ecr - esamp))

                num_ecr = 0  # single entry in nums
                den_ecr = 0  # single entry in dens

                # dEp
                # integral in Ep
                nums_ecr, dens_ecr = self.get_integrand(
                    categ, daughter, enu, accuracy, prpl, ecr, particle)
                num_ecr = integrate.trapz(
                    np.sum(nums_ecr, axis=1) * pnmarr, esamp)
                den_ecr = integrate.trapz(np.sum(dens_ecr, axis=1), esamp)

                nums.append(num_ecr * cr_flux / Units.phicm2)
                dens.append(den_ecr * cr_flux / Units.phicm2)
            # dEcr
            passed += integrate.trapz(nums, ecrs[istart:])
            total += integrate.trapz(dens, ecrs[istart:])

        return passed, total
def generate_table(interaction_model=None,
                   primary_model=None,
                   density_model=None):

    interaction_model = interaction_model or 'SIBYLL23C'
    primary_model = primary_model or 'H3a'
    density_model = density_model or 'USStd'
    tag = '-'.join((interaction_model.lower(), primary_model.lower(),
                    density_model.lower()))

    weights = None
    if interaction_model == 'YFM':
        # Use weights from Yanez et al., 2019 (https://arxiv.org/abs/1909.08365)
        interaction_model = 'SIBYLL23C'
        weights = {211: 0.141, -211: 0.116, 321: 0.402, -321: 0.583}

    if primary_model == 'GSF':
        primary_model = (crf.GlobalSplineFitBeta, None)
    elif primary_model == 'H3a':
        primary_model = (crf.HillasGaisser2012, 'H3a')
    elif primary_model == 'PolyGonato':
        primary_model = (crf.PolyGonato, None)
    else:
        raise ValueError(f'Invalid primary model: {primary_model}')

    if density_model == 'USStd':
        density_model = ('CORSIKA', ('USStd', None))
    elif density_model.startswith('MSIS00'):
        density_model = ('MSIS00', density_model.split('-')[1:])
    else:
        raise ValueError(f'Invalid density model: {density_model}')

    config.e_min = 1E-01
    config.enable_default_tracking = False
    config.enable_muon_energy_loss = True

    mceq = MCEqRun(interaction_model=interaction_model,
                   primary_model=primary_model,
                   density_model=density_model,
                   theta_deg=0)

    if weights:

        def weight(xmat, egrid, name, c):
            return (1 + c) * numpy.ones_like(xmat)

        for pid, w in weights.items():
            mceq.set_mod_pprod(2212, pid, weight, ('a', w))
        mceq.regenerate_matrices(skip_decay_matrix=True)

    energy = mceq.e_grid
    cos_theta = numpy.linspace(0, 1, 51)
    altitude = numpy.linspace(0, 9E+03, 10)

    data = numpy.zeros((altitude.size, cos_theta.size, energy.size, 2))
    for ic, ci in enumerate(cos_theta):
        print(f'processing {ci:.2f}')

        theta = numpy.arccos(ci) * 180 / numpy.pi
        mceq.set_theta_deg(theta)
        X_grid = mceq.density_model.h2X(altitude[::-1] * 1E+02)
        mceq.solve(int_grid=X_grid)

        for index, _ in enumerate(altitude):
            mu_m = mceq.get_solution('mu-', grid_idx=index) * 1E+04
            mu_p = mceq.get_solution('mu+', grid_idx=index) * 1E+04
            K = (mu_m > 0) & (mu_p > 0)
            data[altitude.size - 1 - index, ic, K, 0] = mu_m[K]
            data[altitude.size - 1 - index, ic, K, 1] = mu_p[K]

    # Dump the data grid to a litle endian binary file
    data = data.astype('f4').flatten()
    with open(f'data/simulated/flux-mceq-{tag}.table', 'wb') as f:
        numpy.array((energy.size, cos_theta.size, altitude.size),
                    dtype='i8').astype('<i8').tofile(f)
        numpy.array((energy[0], energy[-1], cos_theta[0], cos_theta[-1],
                     altitude[0], altitude[-1]),
                    dtype='f8').astype('<f8').tofile(f)
        data.astype('<f4').tofile(f)
Esempio n. 3
0
mceq.set_theta_deg(theta)

altitude = numpy.array((30., ))
X_grid = mceq.density_model.h2X(altitude * 1E+02)


def weight(xmat, egrid, name, c):
    return (1 + c) * numpy.ones_like(xmat)


mceq.set_mod_pprod(2212, 211, weight, ('a', 0.141))  # Coefficients taken
mceq.set_mod_pprod(2212, -211, weight,
                   ('a', 0.116))  # from table 2 of Yanez et
mceq.set_mod_pprod(2212, 321, weight, ('a', 0.402))  # al.
mceq.set_mod_pprod(2212, -321, weight, ('a', 0.583))
mceq.regenerate_matrices(skip_decay_matrix=True)

mceq.solve(int_grid=X_grid)

energy = mceq.e_grid
flux = mceq.get_solution('mu-', grid_idx=0)
flux += mceq.get_solution('mu+', grid_idx=0)

# Plot the result
plot.figure()
plot.semilogx(energy, energy**3 * flux, 'k--')
plot.errorbar(bess.energy,
              bess.energy**3 * bess.flux,
              yerr=bess.energy**3 * bess.dflux,
              fmt='bo',
              label='BESS-TeV')
Esempio n. 4
0
def Solve_mceqs():
    ### This function solves matrix cascade equations using MCEq. Please
    ### note that MCEq can do a lot more than what is currently used
    ### in this script. For more information and options, visit:
    ### https://github.com/afedynitch/MCEq

    import crflux.models as crf
    from MCEq.core import config, MCEqRun

    def Convert_name(particle):
        # MCEq can't handle "bar"s in particle names. It wants "anti"s instead.
        if 'bar' in particle[0]:
            pname = (particle[0].replace('_', '_anti') if '_' in particle[0] else 'anti' + particle[0])
            pname = pname.replace('bar', '')
        else:
            pname = particle[0]
        return pname

    # Cosmic ray flux at the top of the atmosphere:
    primary_model = (HawkBPL, 0.)
    # High-energy hadronic interaction model:
    interaction_model = 'SIBYLL23C'
    # Zenith angles:
    zenith_deg = np.append(np.arange(0., 90., 10), 89)
    mceq = MCEqRun(interaction_model = interaction_model,
                   primary_model = primary_model,
                   theta_deg = 0.)
    mceq.pman.track_leptons_from([(130,0)], 'K0L_')
    mceq.pman.track_leptons_from([(310,0)], 'K0S_')
    # mceq.pman.print_particle_tables(0)
    mceq._resize_vectors_and_restore()
    mceq.regenerate_matrices()
    config.excpt_on_missing_particle = True
    energy = mceq.e_grid

    ## Solve the equation systems for all zenith angles:
    solutions = [[] for particle in particles]
    for angle in zenith_deg:
        print(
            '\n=== Solving MCEq for BPL '
            + interaction_model + ' ' + str(angle) + ' deg'
        )
        mceq.set_theta_deg(angle)
        mceq.solve()

        # Obtain solution for all chosen particles:
        print('Obtaining solution for:')
        for p, particle in enumerate(particles):
            print(particle[0])
            solutions[p].append(mceq.get_solution(Convert_name(particle), mag=0))
            # mag is a multiplication factor in order to stress steaper
            # parts of the spectrum. Don't store magnified fluxes in nuflux
            # (keep mag=0)!

    # Save solutions to file particle-wise:
    for p, particle in enumerate(particles):
        savename = name + '_' + particle[0]
        headr = (
            savename.replace('_', '\t') + '\n'
            'energy [GeV]\t' + ' '.join([str(z) + ' deg\t' for z in zenith_deg])
        )
        solutions[p].insert(0, energy)
        solutions[p] = np.array(solutions[p])
        np.savetxt(
            dirname + '/data/' + savename + '.dat', np.transpose(solutions[p]),
            fmt='%.8e', header=headr, delimiter='\t'
        )