Symbols
Symbol |
Description |
Units |
\(a\) |
minor radius of the torus (horizontal) |
\(m\) |
\(a_{ij}\) |
coefficient of matrix \(A\) |
|
\(A\) |
atomic mass of ion |
|
\(A_i\) |
atomic mass of ion |
|
\(A_\alpha \) |
atomic mass of ion species \(\alpha \) |
|
\([a,b]\) |
arbitrary finite interval |
|
\(\alpha \) |
as suffix is species label or index |
|
\(\alpha _n\) |
perturbation amplitude |
|
\(\alpha ^{Z_p\rightarrow Z}\) |
partial dielectronic recombination rate coefficient |
\(m^3 s^{-1}\) |
\(\alpha ^{Z\rightarrow Z_m}\) |
partial dielectronic recombination rate coefficient |
\(m^3 s^{-1}\) |
\(b\) |
minor radius of the torus (vertical) |
\(m\) |
\(B_0\) |
used to make \(B\) dimensionless |
\(T\) |
\(B_s\) |
characteristic magnetic field used to make \(\bf B\) dimensionless |
\(T\) |
\(\bar {N}_Z\) |
average number of charge states |
|
\(B=|{\bf B}|\) |
amplitude of the imposed magnetic field |
\(T\) |
\(B_T\) |
amplitude of the imposed toroidal magnetic field |
\(T\) |
\(\beta \) |
as suffix is species label |
|
\(\beta \) |
(Glossary) Ratio of plasma pressure to pressure in magnetic field |
|
\({\bf a} = d^2 {\bf x}/dt^2\) |
acceleration experienced by a particle |
\(m^2 s^{-1}\) |
\({\bf A}({\bf x},t)\) |
magnetic vector potential |
\(T m\) |
\({\bf B}({\bf x},t)\) |
magnetic field |
\(T\) |
\(\bf b\) |
unit vector giving the direction of the magnetic field |
|
\({\bf E}({\bf x},t)\) |
electric field |
\(V m^{-1}\) |
\(E_s\) |
characteristic electric field used to make \(\bf E\) dimensionless |
\(V m^{-1}\) |
\({\bf E}^{+}\) |
modified electric field |
\(m^{-2}\) |
\(\bf F\) |
force vector |
\(N\) |
\({\bf u}_\wedge \) |
pseudo / thermal velocity component in flux surface normal to field direction |
\(m s^{-1}\) |
\(\bf v\) |
generic velocity |
\(m s^{-1}\) |
\({\bf v}_\alpha \) |
velocity of species \(\alpha \) |
\(m s^{-1}\) |
\({\bf v}_{\|}\) |
fluid velocity directed along fieldline |
\(m s^{-1}\) |
\({\bf v}_\perp \) |
fluid velocity component normal to flux surface |
\(m s^{-1}\) |
\({\bf v}_\wedge \) |
fluid velocity component in flux surface normal to field direction |
\(m s^{-1}\) |
\({\bf v}_0\) |
initial fluid velocity |
\(m s^{-1}\) |
\({\bf v}_{cx}\) |
‘charge exchange’ perpendicular fluid velocity component |
\(m s^{-1}\) |
\({\bf v}_{E \times B}\) |
‘E cross B’ perpendicular fluid velocity component |
\(m s^{-1}\) |
\({\bf v}_e\) |
velocity of the electrons |
\(m s^{-1}\) |
\({\bf v}_i\) |
velocity of the ion species |
\(m s^{-1}\) |
\({\bf v}_{e \nabla B}\) |
‘grad B’ perpendicular fluid velocity component for electrons |
\(m s^{-1}\) |
\({\bf v}_{i \nabla B}\) |
‘grad B’ perpendicular fluid velocity component for ions |
\(m s^{-1}\) |
\({\bf v}_\textrm {diff}\) |
‘diffusive’ perpendicular fluid velocity component |
\(m s^{-1}\) |
\({\bf x}=\left (x_1,x_2,\dots ,x_d\right )\) |
is a \(d\)-dimensional vector |
|
\(\bf x\) |
position |
\(m\) |
\(b_n\) |
‘b-factors’ ref. [112, slide 21] |
|
\(\boldsymbol {\xi }(\theta )\) |
multi-dimensional random variable with a specific probability distribution as a function of the random parameter \(0\leq \theta \leq 1\) |
|
\(\boldsymbol {B}\) |
(K+S) Basis matrix |
|
\(\boldsymbol {D}_{\xi }\) |
(K+S) Elemental derivative matrix with respect to \(\xi \) |
|
\(\boldsymbol {f}^e\) |
(K+S) Force vector of the \(e\)th element |
|
\(\boldsymbol {H}\) |
(K+S) Helmholtz matrix (\(=\mathcal {A}^T \underline {\boldsymbol {H}^e} \mathcal {A}\))) |
|
\(\boldsymbol {H}^e\) |
(K+S) Elemental Helmholtz matrix |
|
\(\boldsymbol {L}\) |
(K+S) Laplacian matrix (\(=\mathcal {A}^T \underline {\boldsymbol {L}^e} \mathcal {A}\))) |
|
\(\boldsymbol {\Lambda }(u)\) |
(K+S) Diagonal matrix of \(u(\xi _i, \xi _2)\) evaluated at quadrature points |
|
\(\boldsymbol {L}^e\) |
(K+S) Elemental Laplacian matrix |
|
\(\boldsymbol {M}\) |
(K+S) Mass matrix (\(=\mathcal {A}^T \underline {\boldsymbol {M}^e} \mathcal {A}\)) |
|
\(\boldsymbol {\mathcal {A}}^T\) |
(K+S) Matrix global assembly |
|
\(\boldsymbol {M}^e\) |
(K+S) Elemental mass matrix |
|
\(\boldsymbol {n}\) |
(K+S) Unit outward normal |
|
\(\boldsymbol {\omega }\) |
(K+S and plasma models) Vorticity |
\(s^{-1}\) or \(C m^{-3}\) |
\(\boldsymbol {u}^e\) |
(K+S) Vector containing function evaluated at quadrature points |
|
\(\boldsymbol {W}\) |
(K+S) Diagonal weight / Jacobian matrix |
|
\(\boldsymbol {\xi }(\theta )\) |
multi-dimensional random variable with a specific probability distribution as a function of the random parameter \(0\leq \theta \leq 1\) |
|
\(B_p\) |
amplitude of the poloidal magnetic field |
\(T\) |
\(C_0=\sqrt {K_{MA} T_0}\) |
used to make velocities dimensionless |
\(m s^{-1}\) |
\(\cap \) |
(Sets) Set intersection |
|
\(\chi \) |
(K+S) Space of trial solutions |
|
\(\chi ^{\delta }\) |
(K+S) Finite-dimensional space of trial solutions |
|
\(\chi _i(\xi )\) |
(FE Basis) Local Cartesian to global coordinate mapping |
|
\(c_p\) |
specific heat at constant pressure |
\(J kg^{-1} K^{-1}\) |
\(c_s = \sqrt {\frac {kT_i + {Z_i} kT_e}{{m_i}}}\) |
approx. plasma acoustic speed |
\(m s^{-1}\) |
\(c_s = \sqrt {\frac {p}{\rho _m}}\) |
plasma acoustic speed |
\(m s^{-1}\) |
\(c_{se} = \sqrt {\frac {kT_e}{{m_e}}}\) |
acoustic speed of electrons |
\(m s^{-1}\) |
\(c_{si} = \sqrt {\frac {kT_i}{{m_i}}}\) |
acoustic speed of ions |
\(m s^{-1}\) |
\(C_S\) |
sound speed coefficient in radiation equation |
\(m s^{-1}\) |
\(\cup \) |
(Sets) Set union |
|
\(C(x_i, x_j)\) |
covariance of random variables \(x_i\), \(x_j\) |
|
\(d\) |
number of dimensions over which the integral is performed |
|
\(\delta p_i\) |
stress tensor |
\(N m^{-2}\) |
\(\delta \) |
Kronecker delta |
|
\(\delta _D\) |
Dirac delta function |
|
\(\delta _e\) |
energy flux factor at boundary of the electrons |
|
\(\delta =\frac {1}{2}(\delta _e+\delta _i)\) |
energy flux factor at boundary of ‘mean’ species |
|
\(\delta _i\) |
energy flux factor at boundary of the ion species |
|
\(\delta _\alpha \) |
(Glossary) Magnetisation parameter, species \(\alpha \) gyroradius normalised to \(L\) |
|
\(\delta (x)\) |
Dirac delta function of continuous real variable \(x\) |
|
\(D\) |
spatial dimensionality of problem |
|
\(D_A\) |
diffusion coefficient for plasma charges in a background of neutrals |
\(m^2 s^{-1}\) |
\(D_e\) |
diffusion coefficient for electrons, eg. in a background of neutrals |
\(m^2 s^{-1}\) |
\(D_{fv\alpha }\) |
scale dissipation in equation for evolution of species velocity \({\bf v}_\alpha \) |
|
\(D_n\) |
neutral diffusion coefficient |
\(m^2 s^{-1}\) |
\(D_{fp\alpha }\) |
scale dissipation in equation for evolution of species pressure/energy \(p_\alpha \) |
|
\(D_i\) |
diffusion coefficient for ions, eg. in a background of neutrals |
\(m^2 s^{-1}\) |
\(|e|\) |
absolute value of the charge on the electron |
\(C\) |
\(e\) |
(K+S) Finite element number \(1 \leq e \leq N_{el}\) |
|
\(e_{ijk}\) |
weighted integral of triple products of \(\Psi _i\) of the ion species |
|
\(\emptyset \) |
(Sets) Empty set |
|
\(\epsilon _0\) |
permittivity of free space |
\(F m^{-1}\) |
\(\epsilon _r=t_s/t_0\) |
scale factor for transient term |
|
\(\eta _1, \eta _2, \eta _3\) |
(FE Basis) Local collapsed Cartesian coordinates |
|
\(\eta _B\) |
plasma resistivity after Braginskii |
\(\Omega m\) |
\(\eta _d=\eta _B/\mu _0\) |
plasma resistivity, as diffusivity |
\(m^2 s^{-1}\) |
\(\eta _{e{\sf n}}\) |
contribution to plasma resistivity, as diffusivity, from electron-neutral interactions |
\(m^2 s^{-1}\) |
\(\eta _{e{\sf n}\|}\) |
contribution to plasma parallel resistivity, as diffusivity, from electron-neutral interactions |
\(m^2 s^{-1}\) |
\(\eta _{i{\sf n}}\) |
contribution to plasma resistivity, as diffusivity, from ion-neutral interactions |
\(m^2 s^{-1}\) |
\(\eta _{i{\sf n}\|}\) |
contribution to plasma parallel resistivity, as diffusivity, from ion-neutral interactions |
\(m^2 s^{-1}\) |
\(f_0\) |
constant in the expansion of \(f\left (x_1,\ldots ,x_d\right )\) |
|
\(f_0\) |
initial distribution function of the electrons |
\(m^{-6} s^3\) |
\(f_\alpha \) |
distribution function of species \(\alpha \) |
\(m^{-6} s^3\) |
\(f_e\) |
distribution function of the electrons |
\(m^{-6} s^3\) |
\(f_i\) |
distribution function of the ion species |
\(m^{-6} s^3\) |
\(f_{ij}(x_i,x_j)\) |
coefficient in the expansion of \(f\left (x_1,\ldots ,x_d\right )\) |
|
\(f_{ce}= \frac {\omega _{ce}}{2\pi }\) |
electron cyclotron frequency |
\(s^{-1}\) |
\(f_{ci}= \frac {\omega _{ci}}{2\pi }\) |
ion cyclotron frequency |
\(s^{-1}\) |
\(f_{pe}= \frac {\omega _{pe}}{2\pi }\) |
electron plasma frequency |
\(s^{-1}\) |
\(f_{pi}= \frac {\omega _{pi}}{2\pi }\) |
ion plasma frequency |
\(s^{-1}\) |
\(f_i(x_i)\) |
coefficient in the expansion of \(f\left (x_1,\ldots ,x_d\right )\) |
|
\(f\left (x_1,\ldots ,x_d\right )\) |
joint probability distribution |
|
\(f^\mathcal {E}\) |
flux term (fieldline integrated source) for plasma energy |
|
\(F^\mathcal {E}\) |
flux term (fieldline integrated source divided by field) for plasma energy |
\(m^{-1} s^{-2} C\) |
\(f^n\) |
flux term (fieldline integrated source) for plasma number density |
|
\(F^n\) |
flux term (fieldline integrated source divided by field) for plasma number density |
\(m^{-3} C\) |
\(f^u\) |
flux term (fieldline integrated source) for plasma momentum |
|
\(F^u\) |
flux term (fieldline integrated source divided by field) for plasma momentum |
\(m^{-2} s^{-1} C\) |
\(f(x,{\bf v},t)\) |
generic distribution function |
\(m^{-6} s^3\) |
\(f_{n,Kn}({\bf v})\) |
Knudsen distribution function |
\(m^{-4} s^4\) |
\(\Gamma (x)\) |
gamma function of continuous variable \(x\) |
|
\(g\) |
factor in (twice) the heat flux |
|
\(g(h_j)\) |
activation function (of input \(h_j\)) of a neuron in a neural network |
|
\(G\) |
Green’s function |
|
\(H_\alpha \) |
Hamiltonian for species \(\alpha \) |
|
\(\hat {\boldsymbol {u}}^e\) |
(K+S) Vector of expansion coefficients |
|
\(\hat {v}_g\) |
(K+S) Global list of coefficients |
|
\(\hat {v}_g\) |
(K+S) List of all elemental coefficients (\(=\underline {v^e}\)) |
|
\(h\) |
mesh or inter-node spacing |
\(m\) |
\(h_j\) |
real-number input to a neuron in a neural network |
|
\(h_p(\xi )\) |
(FE Basis) One-dimensional Lagrange polynomial of order \(p\) |
|
\(i\) |
as suffix denotes ions |
|
\(i\) |
as suffix denotes regular excited state |
|
\(i\) |
as suffix generic label |
|
\(I\) |
as suffix labels Monte-Carlo interactions |
|
\(I_\phi \) |
\(\phi -\) or toroidal component of plasma current |
\(A\) |
\(I_H\) |
Hydrogen reionisation potential as defined in ref. [113] |
\(eV\) |
\(i,j,k\) |
(K+S) General summation indices |
|
\(^I\mathcal {F}_{i\sigma }\) |
coefficient of ionisation for the transition from metastable state \(\sigma \) to regular excited state \(i\) |
|
\(\in \) |
(Sets) Is a member of; belongs to |
|
\(I(\psi )=B_T/R\) |
function giving the toroidal field as a function of \(\psi \) |
\(T m^{-1}\) |
\(I^Z\) |
power per atom released in dielectronic recombination |
\(W\) |
\(j\) |
as suffix is generic label |
|
\(j_{ext}(R,Z)\) |
electric current density induced in plasma by external coils |
\(A m^{-2}\) |
\(j_\phi \) |
\(\phi -\) or toroidal component of plasma current density |
\(A m^{-2}\) |
\(j_{\|}\) |
component of plasma current density parallel to fieldline |
\(A m^{-2}\) |
\({\bf j}_{sh}\) |
sheath plasma current density |
\(A m^{-2}\) |
\(k\) |
as suffix is generic label |
|
\(k\) |
chosen to scale so that \(kT_0\), \(kT_d\) is an energy |
\(?\) |
\(\kappa _\alpha \) |
thermal diffusivity of species \(\alpha \) |
\(m^2 s^{-1}\) |
\(\kappa _{e\|}\) |
parallel thermal diffusivity of electrons |
\(m^2 s^{-1}\) |
\(\kappa _{e\perp }\) |
perpendicular thermal diffusivity of electrons |
\(m^2 s^{-1}\) |
\(\kappa _{i\|}\) |
parallel thermal diffusivity of ions |
\(m^2 s^{-1}\) |
\(\kappa _{i\perp }\) |
perpendicular thermal diffusivity of ions |
\(m^2 s^{-1}\) |
\(\kappa =k_c/\rho _m c_p\) |
thermal diffusivity tensor of solid |
\(m^2 s^{-1}\) |
\(k_B\) |
Boltzmann’s constant |
\(J K^{-1}\) |
\(k_c\) |
thermal conductivity tensor |
\(J m^{-1} s^{-1} K^{-1}\) |
\(K_{cx}\left ( n_i, T_i \right )\) |
reaction rate of charge exchange reactions |
\(m^3 s^{-1}\) |
\(K_i\) |
ionization reaction rate |
\(m^3 s^{-1}\) |
\(K_{MA}\) |
chosen as \(k_B/m_i\) or \(|e|/m_i\) so that \(\sqrt {K_MT_d}\) is an ion speed |
\(?\) |
\(K_M\) |
chosen as \(k_B/m_u\) or \(|e|/m_u\) so that \(\sqrt {K_MT_d/A}\) is an ion speed |
\(?\) |
\(K_r\) |
recombination reaction rate |
\(m^3 s^{-1}\) |
\(kT_0\) |
\(T_0\) in energy units |
\(J\) |
\(kT_d\) |
\(T_d\) in energy units |
\(J\) |
\(K_v(x)\) |
modified Bessel function of the second kind, order \(v\) |
|
\(k_w\) |
wavenumber vector |
\(m^{-1}\) |
\(\lambda \) |
arbitrary quantity |
\(?\) |
\(\lambda \) |
Coulomb logarithm |
|
\(\lambda \) |
(K+S) Helmholtz equation constant |
|
\(\Lambda \) |
Coulomb logarithm |
|
\(\lambda _q\) |
\(e\)-folding length of midplane profile of power loss when an exponential is fitted |
\(m\) |
\(\Lambda _b\) |
sheath potential drop normalized to \(T_e\) |
\(eV\) |
\(\lambda _D\) |
(Glossary) Debye lengthscale above which local electrostatic fluctuations due to presence of discrete charged particles are negligible |
\(m\) |
\(\lambda _{mfp,\alpha }\) |
(Glossary) Mean free path of particle species \(\alpha \) |
\(m\) |
\(\langle \sigma v \rangle _{CX}\) |
reaction rate for charge exchange |
\(m^3 s^{-1}\) |
\(\langle \sigma v \rangle _{ION}\) |
reaction rate for ionisation |
\(m^3 s^{-1}\) |
\(\langle \sigma v \rangle _{REC}\) |
reaction rate for recombination |
\(m^3 s^{-1}\) |
\(\langle \sigma v\rangle \) |
generic reaction rate |
\(m^3 s^{-1}\) |
\(L_0\) |
typical lengthscale |
\(m\) |
\(L_i^{N_m}(\boldsymbol {\xi })\) |
(FE Basis) Two-dimensional Lagrange polynomial through \(N_m\) nodes \({\mathbf \xi }_i\) |
|
\(L_s\) |
typical lengthscale along fieldline |
\(m\) |
\(L_{\|}\) |
connection length of typical fieldline |
\(m\) |
\(m\) |
species particle mass |
\(kg\) |
\(M_0\) |
Mach number at \(s=0\) boundary |
|
\(M_1\) |
Mach number at \(s=1\) boundary |
|
\(m_\alpha \) |
mass of species \(\alpha \) |
\(kg\) |
\(\mathbb {E}\) |
expectation |
|
\(\mathbb {E}_{k\neq i, l\neq j}\) |
expectation computed by integrating over all the \(x_k\) except for \(x_i\) and \(x_j\) |
|
\(\mathbb {E}_{x_{k\neq i}}\) |
expectation computed by integrating over all the \(x_k\) except for \(x_i\) |
|
\(\mathbb {L}(u)\) |
(K+S) Linear operator in \(u\) |
|
\(\mathbb {P}\) |
(K+S) Projection operator |
|
\(\mathbb {P}^{\delta }\) |
(K+S) Discrete projection operator |
|
\(\mathbf v\) |
(K+S) Velocity \([u, v, w]^T\) |
|
\(\mathcal {E}_\alpha \) |
energy of species \(\alpha \) |
\(J m^{-3}\) |
\(\mathcal {E}_e\) |
energy of the electrons |
\(J m^{-3}\) |
\(\mathcal {E}_i\) |
energy of the ion species |
\(J m^{-3}\) |
\(\mathcal {E}_R\) |
total plasma radiation |
\(W m^{-3}\) |
\(\mathcal {F}\) |
generic coefficient of excitation, ionisation or recombination |
\(m^3 s^{-1}\) |
\(\mathcal {F}_\alpha \) |
functional of moments of species \(\alpha \) |
\(m^{-6} s^3\) |
\(\mathcal {I}\) |
(K+S) Interpolation operator |
|
\(\mathcal {I}^{\delta }\) |
(K+S) Discrete interpolation operator |
|
\(\mathcal {K}_{\|}\) |
parallel thermal conductivity of plasma |
\(m^{-1}s^{-1}\) |
\(\mathcal {K}\) |
thermal conductivity of plasma |
\(m^{-1}s^{-1}\) |
\(\mathcal {K}_{\perp }\) |
thermal conductivity of plasma perpendicular to field and flux surface |
\(m^{-1}s^{-1}\) |
\(\mathcal {K}_{\wedge }\) |
thermal conductivity of plasma perpendicular to field in flux surface |
\(m^{-1}s^{-1}\) |
\(\mathcal {L}_7\) |
7-D Lie derivative (space, velocity-space and time make up the \(3+3+1=7\) dimensions) |
\(s^{-1}\) |
\(\mathcal {P}_{P}(\Omega )\) |
(K+S) Polynomial space of order \(P\) over \(\Omega \) |
|
\(\mathcal {Q}\) |
coefficient in radiation equation |
\(m^3 s^{-1}\) |
\(\mathcal {Q}_{\sigma \rightarrow \rho }^{Z\rightarrow Z}\) |
parent-metastable cross-coupling coefficient |
\(m^3 s^{-1}\) |
\(\mathcal {S}\) |
coefficient in radiation equation |
\(m^3 s^{-1}\) |
\(\mathcal {S}^{Z_m\rightarrow Z}\) |
ionisation coefficient |
\(m^3 s^{-1}\) |
\(\mathcal {S}^{Z\rightarrow Z_p}\) |
ionisation coefficient |
\(m^3 s^{-1}\) |
\(\mathcal {T}\) |
generic tensor |
\(?\) |
\(\mathcal {V}\) |
(K+S) Space of test functions |
|
\(\mathcal {V}^{\delta }\) |
(K+S) Finite-dimensional space of test functions |
|
\(\mathcal {X}\) |
coefficient in radiation equation |
\(m^3 s^{-1}\) |
\(\mathcal {X}_{\sigma \rightarrow \rho }^{Z\rightarrow Z}\) |
generalised collisional-radiative (GCR) excitation coefficient |
\(m^3 s^{-1}\) |
\(\mathfrak {R}\) |
Real numbers |
|
\(\mathrm {Var}(f)\) |
variance of the distribution of \(f\) computed by integrating over all variables \(x_i\) |
|
\(\mathrm {Var}[Q]\) |
variance in random variable \(Q\) |
|
\(m_e\) |
mass of electron |
\(kg\) |
\(m_i\) |
mass of ion species particle \(m_i= A m_u\) |
\(kg\) |
\(m_n\) |
neutral species particle mass |
\(kg\) |
\(m_p\) |
mass of proton |
\(kg\) |
\(m_u\) |
atomic mass unit |
\(1.6605 \times 10^{-27}\,kg\) |
\(M_s\) |
Mach number, allowed to take either sign |
|
\(M_S\) |
number of energy states of an atom |
|
\(\mu , \nu \) |
(K+S) Dynamic, kinematic viscosities |
|
\(\mu _{cx}=\omega _c/\nu _{cx}\) |
measures strength of magnetization with respect to charge exchange reaction |
|
\(\mu _m\) |
reduced mass of two particles |
\(kg\) |
\(M_Z\) |
number of metastable states for species \(\alpha \) (which includes the ground state) |
|
\(n\) |
number density |
\(m^{-3}\) |
\(n_{ref}\) |
reference number density of the plasma ions |
\(m^{-3}\) |
\(N_{ref} \) |
normalising or reference number density |
\(10^{18}\) |
\(N\) |
number density, may be scaled by \(N_{ref}=10^{18}\) |
\(m^{-3}\) |
\(n_0\) |
initial number density |
\(m^{-3}\) |
\(\nabla \cdot \) |
(K+S) Divergence |
|
\(\nabla \times \) |
(K+S) Curl |
|
\(\nabla ^2\) |
(K+S) Laplacian |
|
\(N_{b}\) |
(K+S) Number of global boundary degrees of freedom |
|
\(n_B=N/B\) |
number density divided by field strength |
\(m^{-3}T^{-1}\) |
\(N_D\) |
Number of degrees of freedom per dimension, \(D=1,2,\ldots 6\) |
|
\(N_{dof}\) |
(K+S) Number of global degrees of freedom |
|
\(n_{con}\) |
blob contrast factor |
|
\(n_e\) |
number density of the electrons |
\(m^{-3}\) |
\(N_{el}\) |
(K+S) Number of finite elements |
|
\(N_{eof}\) |
(K+S) Total number of elemental degrees of freedom \(N_{eof} \simeq N_{el}N_m\) |
|
\(n_i\) |
number density of the plasma ions |
\(m^{-3}\) |
\(n_j({\bf x},t)\) |
member of the set of deterministic coefficients of the “random trial basis" |
|
\(N_{m}\) |
(K+S) Number of elemental degrees of freedom |
|
\(n_n\) |
neutral density |
\(m^{-3}\) |
\(\notin \) |
(Sets) Is not a member of; does not belong to |
|
\(\not \subset \) |
(Sets) Is not a subset of |
|
\(n_p\) |
number density of the plasma ions |
\(m^{-3}\) |
\(N_{Q}\) |
(K+S) Total number of quadrature points \(N_Q = Q_1 Q_2 Q_3\) |
|
\(n_s\) |
number density of isotope \(s\) |
\(m^{-3}\) |
\(N_s\) |
number density of isotope \(s\) |
\(m^{-3}\) |
\(N_T\) |
number of samples in temperature used to define typically a crossection in the ADAS database refs. [114, 115] |
|
\(\nu \) |
plasma kinematic viscosity |
\(m^2 s^{-1}\) |
\(\nu _\alpha \) |
kinematic viscosity of species \(\alpha \) |
\(m^2 s^{-1}\) |
\(\nu _{cx}=K_{cx} n_n\) |
charge exchange ‘frequency’ |
\(s^{-1}\) |
\(\nu _{e0}\) |
electron kinematic viscosity caused by neutrals |
\(m^2 s^{-1}\) |
\(\nu _{e\|}\) |
parallel kinematic viscosity of electrons |
\(m^2 s^{-1}\) |
\(\nu _{e\perp }\) |
perpendicular kinematic viscosity of electrons |
\(m^2 s^{-1}\) |
\(\nu _{i\|}\) |
parallel kinematic viscosity of ions |
\(m^2 s^{-1}\) |
\(\nu _i\) |
ion kinematic viscosity |
\(m^2 s^{-1}\) |
\(\nu _{i0}\) |
ion kinematic viscosity caused by neutrals |
\(m^2 s^{-1}\) |
\(\nu _{i\perp }\) |
perpendicular kinematic viscosity of ions |
\(m^2 s^{-1}\) |
\(\nu ^{*}_\alpha \) |
(Glossary) Normalised collision frequency for species \(\alpha \) |
|
\(\nu ^{*}_c = \frac {q_e^4}{3 m_p^2\epsilon _0^2} L_0 n_0 /C_0^4\) |
Collisionality parameter |
|
\(\nu _\alpha \) |
(Glossary) Collision frequency for species \(\alpha \) |
\(s^{-1}\) |
\(\nu _{\alpha {\sf n}}\) |
Collision frequency for species \(\alpha \) with neutrals |
\(s^{-1}\) |
\(\nu _{\alpha \beta }\) |
Collision frequency for species \(\alpha \) with species \(\beta \) |
\(s^{-1}\) |
\(n^Z\) |
number density for charge state \(Z\) |
\(m^{-3}\) |
\(N_P\) |
number of particles in a calculation |
|
\(N_{P\alpha } \) |
number of particles of species \(\alpha \) in a calculation |
|
\(N_Z\) |
number of charge states for an ion species |
|
\(n^Z_i\) |
number density for charge state \(Z\), excited state \(i\) |
\(m^{-3}\) |
\(n^Z_\sigma \) |
number density for charge state \(Z\), metastable state \(\sigma \) |
\(m^{-3}\) |
\(\omega _{ce}= |e|B/m_e\) |
electron cyclotron angular frequency |
\(radians s^{-1}\) |
\(\omega _{ci}= Z_i e B/m_i\) |
ion cyclotron angular frequency |
\(radians s^{-1}\) |
\(\omega _{pe}= \sqrt {\frac {nq_e^2}{\epsilon _0 m_e}}\) |
plasma angular frequency for electrons |
\(radians s^{-1}\) |
\(\omega _{pi}= Z_i\sqrt {\frac {nq_e^2}{\epsilon _0 m_i}}\) |
plasma angular frequency for ions |
\(radians s^{-1}\) |
\(\Omega \) |
(K+S) Solution domain |
|
\(\Omega ^e\) |
(K+S) Elemental region |
|
\(\mathrm {p}(A|B)\) |
conditional probability of event \(A\) given event \(B\) is known or assumed to have occurred |
|
\(p_\alpha \) |
pressure of species \(\alpha \) |
\(N m^{-2}\) |
\(\parallel Q \parallel _E \) |
the ‘energy’ norm |
|
\((\partial f/\partial t)_C\) |
source in Boltzmann due to inter-particle interactions |
\(m^{-6} s^2\) |
\(\partial \Omega _e\) |
(K+S) Boundary of \(\Omega ^e\) |
|
\(\partial \Omega \) |
(K+S) Boundary of \(\Omega \) |
|
\(\partial \Omega _{\mathcal D}\) |
(K+S) Domain boundary with Dirichlet conditions |
|
\(\partial \Omega _{\mathcal N}\) |
(K+S) Domain boundary with Neumann conditions |
|
\(P_C\) |
number of modes in basis for polynomial chaos |
|
\(p_e\) |
pressure of the electrons |
\(N m^{-2}\) |
\(\phi \) |
angle in toroidal direction |
radians \(^c\) |
\(\Phi \) |
electr(ostat)ic potential |
\(V\) |
\(\phi _{pq}, \phi _{pqr}\) |
(FE Basis) Expansion basis |
|
\(\phi _{e,\xi }\) |
(FE Basis) expansion basis as a function of global position \(\bf x\) |
|
\(p\) |
(K+S) pressure |
\(N m^{-2}\) |
\(p = \sum _\alpha n_\alpha kT_\alpha \) |
plasma pressure |
\(N m^{-2}\) |
\(p\) |
as suffix labels (super-)particles |
|
\(p_i\) |
pressure of the ion species |
\(N m^{-2}\) |
\(P_i\) |
(FE Basis) Polynomial order in the \(i\)th direction |
|
\(p(\psi )\) |
function giving the pressure as a function of \(\psi \) of the magnetic flux |
\(N m^{-2}\) |
\(p,q,r\) |
(K+S) General summation indices |
|
\(Pr\) |
Prandtl number |
|
\(Pr_M\) |
magnetic Prandtl number |
|
\(\psi \) |
poloidal magnetic flux |
\(T m^2\) |
\(\psi ^a_p, \psi ^b_{pq}, \psi ^c_{pqr}\) |
(FE Basis) Modified principal functions |
|
\(\Psi _i\) |
\(i^{th}\) member of a set of basis functions, typically multi-dimensional Hermite polynomials |
|
\(P(T)\) |
emitted power integrated over all wavelengths |
\(W m^3\) |
\(\mathrm {p}(x)\) |
probability distributions |
|
\(P(x)\) |
Cumulant probability distribution |
|
\(P^Z\) |
radiated power per atom of \(n^Z\) |
\(W\) |
\(Q_\|\) |
combined energy flux at a boundary |
\(J m^{-2} s^{-1}\) |
\(q_\alpha \) |
charge on a particle of species \(\alpha \) |
\(C\) |
\(q_e\) |
charge on an electron, negative by convention |
\(C\) |
\(Q(f_\alpha , f_\beta )\) |
Boltzmann collision operator |
\(m^{-6} s^2\) |
\(Q_H\) |
cooling rate due to excitation as defined in ref. [113] |
\(K m^{-3} s^{-1}\) |
\(q_i\) |
charge on an ion |
\(C\) |
\(q_{\|e}\) |
electron energy flux along fieldline |
\(J m^{-2} s^{-1}\) |
\(q_{\|i}\) |
ion energy flux along fieldline |
\(J m^{-2} s^{-1}\) |
\({\bf q}_e\) |
electron energy flux |
\(J m^{-2} s^{-1}\) |
\({\bf q}_i\) |
ion energy flux |
\(J m^{-2} s^{-1}\) |
\(Q_i\) |
(FE Basis) Quadrature order in the \(i\)th direction |
|
\(Q_{ie}\) |
collisional energy equipartition term |
\(kg m^{-1} s^{-3}\) |
\(r\) |
order of higher order term |
|
\(r_0\) |
radius used in initial condition, such as blob size |
\(m\) |
\(R\) |
cylindrical coordinate |
\(m\) |
\(R_0\) |
major radius of torus |
\(m\) |
\(R_p\) |
recycling coefficient for particles |
|
\(R_E\) |
recycling coefficient for particle energy |
|
\(\rho \) |
as suffix is label of metastable state |
|
\(\rho \) |
(K+S) Density |
|
\(\rho _c=\sum _\alpha Z_\alpha |e| n_\alpha \) |
charge density of the medium |
\(C m^{-3}\) |
\(\rho _m=\sum _\alpha A_\alpha m_u n_\alpha \) |
mass density of the medium |
\(kg m^{-3}\) |
\(\rho _{t\alpha }\) |
(Glossary) Gyroradius or Larmor radius of orbit of charged particle of species \(\alpha \) about magnetic field direction |
\(m\) |
\(^R\mathcal {F}_{i\sigma }\) |
coefficient of recombination for the transition from metastable state \(\sigma \) to regular excited state \(i\) |
|
\(s_{\|}\) |
arclength along fieldline |
\(m\) |
\(s\) |
as suffix, isotope label (\(\alpha \) preferred for species) |
|
\(s\) |
parameterises distance along the fieldline \(0\leq s \leq 1\) |
|
\(S_\alpha \) |
source term in Boltzmann equation for species \(\alpha \) |
\(m^{-6} s^2\) |
\(S_C\) |
total source term in Boltzmann equation |
\(m^{-6} s^2\) |
\(S_\mathrm {ana}({\bf x},t)\) |
explicit/analytic source term in fluid equation(s) |
\(m^{-3} s^{-1}\) ? |
\(S^n_\mathrm {ana}({\bf x},t)\) |
numerically convenient source term in fluid equation(s) |
\(m^{-3} s^{-1}\) ? |
\(S_{exp}({\bf x}, {\bf v},t)\) |
explicit source term in Boltzmann equation |
\(m^{-6} s^2\) |
\(\sf n\) |
neutral density |
|
\(\sf T\) |
neutral temperature |
|
\(\sf u\) |
neutral velocity |
|
\(s_i\) |
arclength parameter for boundary (\(i=1\) inner, \(i=2\) outer) |
|
\(s^\mathcal {E}\) |
source term in plasma energy equation |
|
\(s^{\mathcal {E}}_{e}\) |
energy density source term for electrons |
|
\(s^{\mathcal {E}}_{i}\) |
energy density source term for ions |
|
\(s^\mathcal {E}_n\) |
source term in neutral energy equation |
|
\(s^\mathcal {E}_{\perp e}\) |
energy cross-field source term for electrons |
|
\(s^\mathcal {E}_{\perp i}\) |
energy cross-field source term for ions |
|
\(s^\mathcal {E}_{\perp n}\) |
energy cross-field source term for neutrals |
|
\(s^n\) |
source term in plasma density equation |
|
\(s^n_n\) |
source term in neutral density equation |
|
\(s^n_{e}\) |
number density source term for electrons |
|
\(s^n_{i}\) |
number density source term for ions |
|
\(s^u\) |
source term in plasma momentum equation |
|
\(s^u_n\) |
source term in neutral momentum equation |
|
\(s^u_{\perp n}\) |
momentum cross-field source term for neutrals |
|
\(S_i\) |
Sobol sensitivity index, gives a normalised measure of the sensitivity of the distribution of \(f\) to the parameter \(x_i\) |
|
\(\sigma \) |
as suffix labels metastable state |
|
\(\sigma \) |
reaction cross-section |
\(m^2\) |
\(\sigma _C\) |
reaction rate for charge exchange |
|
\(\sigma _E\) |
cooling rate due to excitation |
|
\(\sigma _E\) |
electrical conductivity |
\(\Omega ^{-1} m^{-1}\) |
\(\sigma _I\) |
reaction rate for ionisation |
|
\(\sigma _s^{i|0}\) |
collision cross-section for ions with neutrals |
\(m^2\) |
\(\sigma _s^{e|0}\) |
collision cross-section for electrons with neutrals |
\(m^2\) |
\(S_{ij}\) |
Sobol sensitivity index, gives a normalised measure of the sensitivity of the distribution of \(f\) to the parameters \(x_i\) and \(x_j\) |
|
\(S^\mathcal {E}\) |
source term in plasma energy equation |
\(kg m^{-1} s^{-3}\) |
\(S^{\mathcal {E}}_{e}\) |
energy density source term for electrons |
\(kg m^{-1} s^{-3}\) |
\(S^{\mathcal {E}}_{i}\) |
energy density source term for ions |
\(kg m^{-1} s^{-3}\) |
\(S^\mathcal {E}_n\) |
source term in neutral energy equation |
\(kg m^{-1} s^{-3}\) |
\(S^\mathcal {E}_{\perp e}\) |
energy cross-field source term for electrons |
\(kg m^{-1} s^{-3}\) |
\(S^\mathcal {E}_{\perp i}\) |
energy cross-field source term for ions |
\(kg m^{-1} s^{-3}\) |
\(S^\mathcal {E}_{\perp n}\) |
energy cross-field source term for neutrals |
\(kg m^{-1} s^{-3}\) |
\(S^n\) |
source term in plasma density equation |
\(m^{-3} s^{-1}\) |
\(S^n_{e}\) |
number density source term for electrons |
\(m^{-3} s^{-1}\) |
\(S^n_{i}\) |
number density source term for ions |
\(m^{-3} s^{-1}\) |
\(S^n_n\) |
source term in neutral density equation |
\(m^{-3} s^{-1}\) |
\(S^n_{\perp n}\) |
number density cross-field source term for neutrals |
\(m^{-3} s^{-1}\) |
\(S^n_{\perp }\) |
number density cross-field source term for plasma |
\(m^{-3} s^{-1}\) |
\(S_{\perp n}\) |
generic cross-field source term for neutrals |
\(m^{-3} s^{-1}\) |
\(S^u\) |
source term in plasma momentum equation |
\(kg m^{-2} s^{-2}\) |
\(\subset \) |
(Sets) Is a subset of |
|
\(S^u_n\) |
source term in neutral momentum equation |
\(kg m^{-2} s^{-2}\) |
\(S^u_{\perp n}\) |
momentum cross-field source term for neutrals |
\(kg m^{-2} s^{-2}\) |
\(S^Z_\rho \) |
particle source for ion of metastable state \(\sigma \) (species \(\alpha \)) with charge state \(Z\) |
\(m^{-3} s^{-1}\) |
\(S^Z_\alpha \) |
particle source for ion of species \(\alpha \) with charge state \(Z\) |
\(m^{-3} s^{-1}\) |
\(t\) |
time usually in seconds |
\(s\) |
\(t'\) |
offset time usually in seconds |
\(s\) |
\(T\) |
plasma temperature |
\(eV\) |
\(t_0\) |
characteristic evolutionary timescale usually in seconds |
\(s\) |
\(t_s\) |
characteristic timescale usually in seconds |
\(s\) |
\(t_H\) |
Numerical hand-off time interval usually in seconds |
\(s\) |
\(t_R\) |
Numerical ramp-up time interval usually in seconds |
\(s\) |
\(T_0\) |
initial temperature (prefixed by \(k\) implies energy in SI) |
\(eV\) |
\(T_{Kn}\) |
reference temperature of Knudsen distribution (prefixed by \(k\) implies energy in SI) |
\(eV\) |
\(T_{ref}\) |
reference temperature (prefixed by \(k\) implies energy in SI) |
\(eV\) |
\(T_s\) |
characteristic temperature (\(T_s=(L_s/t_s)^2/K_M\)) |
\(eV\) |
\(T_\alpha \) |
temperature of species \(\alpha \) |
\(eV\) |
\(\tau \) |
optical depth |
\(m\) |
\(\tau _\alpha \) |
collision or relaxation time of species \(\alpha \) |
\(s\) |
\(\tau _e\) |
electron collision or relaxation time |
\(s\) |
\(\tau _i\) |
ion species collision or relaxation time |
\(s\) |
\(\tau _{e{\sf n}} \) |
electron-neutral collision time |
\(s\) |
\(\tau _{i{\sf n}} \) |
ion species-neutral collision time |
\(s\) |
\(\tau _{ce}=1/f_{ce}\) |
electron cyclotron timescale |
\(s\) |
\(\tau _{ci}=1/f_{ci}\) |
ion cyclotron timescale |
\(s\) |
\(\tau _{pe}=1/f_{pe}\) |
plasma timescale for electrons |
\(s\) |
\(\tau _{pi}=1/f_{pi}\) |
plasma timescale for ions |
\(s\) |
\(\tau _{\mathcal {E}_e}\) |
loss time of energy density for electrons |
\(s\) |
\(\tau _{\mathcal {E}_i}\) |
loss time of energy density for ions |
\(s\) |
\(\tau _{n_e}\) |
loss time of number density for electrons |
\(s\) |
\(\tau _{n_i}\) |
loss time of number density for ions |
\(s\) |
\(T_d=T_i+T_e\) |
combined temperature of the electrons and ions |
\(eV\) |
\(T_e\) |
electron temperature (prefixed by \(k\) implies energy in SI) |
\(eV\) |
\(T_H\) |
the Hydrogen reionisation potential |
|
\(\theta \) |
angular coordinate |
radians \(^c\) |
\(\theta \) |
random parameter \(0\leq \theta \leq 1\) |
|
\(T_i\) |
ion temperature |
\(eV\) |
\(\tilde {a}\) |
scaled matrix coefficient |
|
\(\tilde {b}=B/B_0\) |
dimensionless magnetic field |
|
\(\tilde {\psi }^a_p, \tilde {\psi }^b_{pq}, \tilde {\psi }^c_{pqr}\) |
(FE Basis) Orthogonal principal functions |
|
\(u\) |
generic first velocity component |
\(m s^{-1}\) |
\(U\) |
velocity component (flow) along fieldline |
\(m s^{-1}\) |
\(U_\alpha \) |
velocity component (flow) along fieldline of species \(\alpha \) |
\(m s^{-1}\) |
\(U_d =L_s/t_0\) |
speed measuring the importance of the transient term |
\(m s^{-1}\) |
\(U_s =L_s/t_s\) |
characteristic speed |
\(m s^{-1}\) |
\(U_A\) |
Alfvén speed |
\(m s^{-1}\) |
\(\underline {\boldsymbol {f}^e}\) |
(K+S) Concatenation of elemental vector \(\boldsymbol {f}^e\) |
|
\(\underline {\boldsymbol {W}^e}\) |
(K+S) Block-diagonal extension of matrix \(\boldsymbol {W}^e\) |
|
\(u_R=1/R\) |
Radial component of Grad-Shafranov ‘flow’ |
|
\(v\) |
generic second velocity component |
\(m s^{-1}\) |
\(v_{\|}\) |
fluid velocity component along fieldline |
\(m s^{-1}\) |
\(V^e\) |
spatial volume occupied by finite element \(e\) |
\(m^3\) |
\(V_i\) |
variance of the distribution of \(f\) as the parameter \(x_i\) varies |
|
\(V_{ij}\) |
variance of the distribution of \(f\) as the parameters \(x_i\) and \(x_j\) vary |
|
\(w\) |
generic third velocity component |
\(m s^{-1}\) |
\(w_{jk}\) |
weight in neural network indexed by neuron \(j\) and input \(k\) |
|
\(w_p\) |
weight of particle \(p\) |
|
\(w_{\alpha ,ref}\) |
normalising or reference weight of particle of species \(\alpha \) |
|
\(w_{ref} \) |
normalising or reference number for superparticles |
\(10^{10}\) |
\(W\) |
weighting function for particle-in-cell |
|
\(x\) |
Cartesian coordinate |
\(m\) |
\(x_0\) |
coordinate value used in specifying initial condition, eg. blob position |
\(m\) |
\(x_1, x_2, x_3, {\mathbf x}\) |
(FE Basis) Global Cartesian coordinates |
|
\(x_\alpha \) |
collisionality factor of species \(\alpha \) |
|
\(x_e = \omega _{ce}\tau _e\) |
collisionality factor of electrons |
|
\(x_i = \omega _{ci}\tau _i\) |
collisionality factor of ions |
|
\(x_i\) |
generic parameter or variable |
|
\(\xi _1, \xi _2, \xi _3, \boldsymbol {\xi }\) |
(FE Basis) Local Cartesian coordinates |
|
\(\xi _i\) |
random number within the unit interval \([0,1]\) |
|
\(^X\mathcal {F}_{i\sigma }\) |
coefficient of excitation for the transition from metastable state \(\sigma \) to regular excited state \(i\) |
|
\(y\) |
Cartesian coordinate |
\(m\) |
\(y_0\) |
coordinate value used in specifying initial condition, eg. blob position |
\(m\) |
\(z\) |
Cartesian coordinate |
\(m\) |
\(z_0\) |
coordinate value used in specifying initial condition |
\(m\) |
\(Z\) |
Cartesian coordinate |
\(m\) |
\(Z\) |
charge state of the ion |
|
\(Z\) |
cylindrical coordinate |
\(m\) |
\(Z_0(\alpha )\) |
number of charge states of species \(\alpha \) included in the model |
|
\(Z_a\) |
Gaussian random process, index \(a\) |
|
\(\zeta \) |
magnetic Prandtl number as defined in Cambridge |
|
\(\zeta =-\phi \) |
toroidal angle coordinate |
radians \(^c\) |
\(Z_{eff}\) |
effective charge state of plasma ions |
|
\(Z_i\) |
charge state of ion |
|
\(Z_\alpha \) |
charge state of ion species \(\alpha \) |
|
\(Z_m=Z-1\) |
where \(Z\) is ion charge state |
|
\(Z_p=Z+1\) |
where \(Z\) is ion charge state |
|
\(Z_{sum}=\sum _\alpha Z_0(\alpha )\) |
where \(Z_0\) is number of charge states of species \(\alpha \) |
|