connection_length_m Module

Connection length and shortest distance to the target routines


Uses


Functions

public function connection_length(equi, x, y, phi, dphi_max, maxstep)

It computes the connection length for the field line defined by x, y, phi (the distance from boundary to boundary). If (x, y, phi) is located inside the wall, the output is negative. If (x, y, phi) is located in the closed flux surface region, the output is the largest allowable number for PARALLAX precision. If the boundary is reached along the field line, but only in one direction, then the routine will return with the arclength to the found boundary point plus the arclength up to dphi_max in the other direction.

Arguments

Type IntentOptional Attributes Name
class(equilibrium_t), intent(inout), target :: equi

Equilibrium defining the field line
real(kind=FP), intent(in) :: x

Spatial coordinate x at which the field line is located
real(kind=FP), intent(in) :: y

Spatial coordinate y at which the field line is located
real(kind=FP), intent(in) :: phi

Spatial coordinate phi at which the field line is located
real(kind=FP), intent(in) :: dphi_max

Maximum toroidal angle to be traced
real(kind=FP), intent(in), optional :: maxstep

Maximum stepsize for the DOP853 integrator

Return Value real(kind=fp)


Subroutines

public subroutine shortest_dist_to_bound(equi, x, y, phi, dphi_max, shortest_dist, maxstep, dirind)

It computes the shortest distance to the boundary along B. If (x, y, phi) is located inside the wall, the output is negative. If (x, y, phi) is located in the closed flux surface region, the output is the largest allowable number for PARALLAX precision.

Arguments

Type IntentOptional Attributes Name
class(equilibrium_t), intent(inout), target :: equi

Equilibrium defining the field line
real(kind=FP), intent(in) :: x

Spatial coordinate x at which the field line is located
real(kind=FP), intent(in) :: y

Spatial coordinate y at which the field line is located
real(kind=FP), intent(in) :: phi

Spatial coordinate phi at which the field line is located
real(kind=FP), intent(in) :: dphi_max

Maximum toroidal angle to be traced
real(kind=FP), intent(out) :: shortest_dist

Shortest distance to boundary along the field line from (x,y,phi)
real(kind=FP), intent(in), optional :: maxstep

Maximum stepsize for the DOP853 integrator
integer, intent(out), optional :: dirind

Refers to the direction to the closest boundary along B: = 1, if the closest transition is in the +phi direction = -1, if the closest transition is in the -phi direction = 0, if the it could not found any boundary along the field line.