Esempio n. 1
0
    def set_hydro_num(self, T, ndens):
        """Sets the  matrix of momentum relaxation collsion rates formulated 
        in the above reference for a system described by hydrodynamics, i.e.
        only a single temperature is avaliable.
    
        Parameters
        ----------
        T : float 
            System temperature in units of energy/kb
        ndens : (N,) np.ndarray
            Number density of each ion species in units of 1/length^{3}.

        """
        leff = get_leff(T, T, self.zsolver.zbars, ndens, self.cd, o=self.o)
        #set each upper triangular nu to g
        for i in range(ndens.shape[0]):
            for j in range(i, ndens.shape[0]):
                self.nu[i, j] = self.zsolver.zbars[i]*self.zsolver.zbars[j]
                self.nu[i,j] = self.nu[i,j]*self.cd['e']*self.cd['e']
                self.nu[i,j] = self.cd['kc']*self.nu[i,j]/leff/(self.cd['kb']*T)
        self.nu = 128.0*np.pi*np.pi*get_calk(1, 1, self.nu)/3.0/np.power(2*np.pi, 1.5)
        #set each lower triangular element to its upper triangular equivalent
        for i in range(ndens.shape[0]):
            for j in range(i, ndens.shape[0]):
                self.nu[i,j] = self.nu[i,j]*np.power(self.zsolver.zbars[i]*\
                                    self.zsolver.zbars[j]*self.cd['e']*self.cd['e'], 2.0)
                self.nu[i,j] = self.nu[i,j]*np.sqrt(self.mass[i]*self.mass[j])
                self.nu[i,j] = self.nu[i,j]/np.sqrt((self.mass[i] + self.mass[j]))
                self.nu[i,j] = ndens[i]*ndens[j]*self.nu[i,j]
                self.nu[i,j] = self.nu[i,j]/np.power(self.cd['kb']*T, 1.5)
                self.nu[j,i] = self.nu[i,j]
        for i in range(ndens.shape[0]):
            self.nu[i, :] = self.cd['kc']*self.cd['kc']*self.nu[i, :]/(self.mass[i]*ndens[i])
Esempio n. 2
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def get_kinetic_num(Te, T, Zbar, ndens, mass, cd, o=3):
    """Returns the  matrix of momentum relaxation collsion rates formulated 
    in the above reference for a system described by kinetics, i.e.
    each ion species has its own temperature.
    
    Parameters
    ----------
    Te : float
        System electron temperature.
    T : (N,) np.ndarray 
        System ion temperatures in units of energy/kb
    Zbar : (N,) np.ndarray
        The effective charge of each ion species in units of electron
        charge.
    ndens : (N,) np.ndarray
        Number density of each ion species in units of 1/length^{3}.
    cd : dict
        A dictionary holding all of the fundamental constants in the same
        units as the other input args (`ndens`, `T`, `masses`). Must have
        the following keys: na, kb, e, g, hbar, c, kc, me, mp.
    mass : (N,) np.ndarray
        Mass of each species.
    o : {3, 1, 2}, optional
        Order of approximation to use. 1->appx with max 2.5% relative error,
        2->appx with max 1.1% relative error, and 3->'exact' (with fermi 
        integral fits).

    Returns
    -------
    nu : (N, N) np.ndarray
        The collision frequencies between each species. 
    """
    leff = get_leff(Te, T, Zbar, ndens, cd, o=o)
    nu = np.zeros((ndens.shape[0], ndens.shape[0]), dtype=ndens.dtype)
    #set each upper triangular nu to g
    for i in range(ndens.shape[0]):
        for j in range(i, ndens.shape[0]):
            nu[i,
               j] = Zbar[i] * Zbar[j] * cd['e'] * cd['e'] * (mass[i] + mass[j])
            nu[i, j] = nu[i, j] / leff / (cd['kb'] *
                                          (mass[i] * T[j] + mass[j] * T[i]))
    nu = 128.0 * np.pi * np.pi * get_calk(1, 1, nu) / 3.0 / np.power(
        2 * np.pi, 1.5)
    #set each lower triangular element to its upper triangular equivalent
    for i in range(ndens.shape[0]):
        for j in range(i, ndens.shape[0]):
            nu[i, j] = nu[i, j] * np.power(
                Zbar[i] * Zbar[j] * cd['e'] * cd['e'], 2.0)
            nu[i,
               j] = nu[i, j] * np.sqrt(mass[i] * mass[j]) * (mass[i] + mass[j])
            nu[i, j] = ndens[i] * ndens[j] * nu[i, j]
            nu[i, j] = nu[i, j] / np.power(
                cd['kb'] * (mass[i] * T[j] + mass[j] * T[i]), 1.5)
            nu[j, i] = nu[i, j]
    for i in range(ndens.shape[0]):
        nu[i, :] = nu[i, :] / (mass[i] * ndens[i])
    return nu