double JF12Field::getTurbulentStrength(const Vector3d& pos) const {
if (pos.getR() > 20 * kpc)
return 0;
double r = sqrt(pos.x * pos.x + pos.y * pos.y); // in-plane radius
double phi = pos.getPhi(); // azimuth
// disk
double bDisk = 0;
if (r < 5 * kpc) {
bDisk = bDiskTurb5;
} else {
// spiral region
double r_negx = r * exp(-(phi - M_PI) / tan90MinusPitch);
if (r_negx > rArms[7])
r_negx = r * exp(-(phi + M_PI) / tan90MinusPitch);
if (r_negx > rArms[7])
r_negx = r * exp(-(phi + 3 * M_PI) / tan90MinusPitch);
for (int i = 7; i >= 0; i--)
if (r_negx < rArms[i])
bDisk = bDiskTurb[i];
bDisk *= (5 * kpc) / r;
}
bDisk *= exp(-0.5 * pow(pos.z / zDiskTurb, 2));
// halo
double bHalo = bHaloTurb * exp(-r / rHaloTurb)
* exp(-0.5 * pow(pos.z / zHaloTurb, 2));
// modulate turbulent field
return sqrt(pow(bDisk, 2) + pow(bHalo, 2));
}
Vector3d JF12Field::getRegularField(const Vector3d& pos) const {
Vector3d b(0.);
double r = sqrt(pos.x * pos.x + pos.y * pos.y); // in-plane radius
double d = pos.getR(); // distance to galactic center
if ((d < 1 * kpc) or (d > 20 * kpc))
return b; // 0 field for d < 1 kpc or d > 20 kpc
double phi = pos.getPhi(); // azimuth
double sinPhi = sin(phi);
double cosPhi = cos(phi);
double lfDisk = logisticFunction(pos.z, hDisk, wDisk);
// disk field
if (r > 3 * kpc) {
double bMag;
if (r < 5 * kpc) {
// molecular ring
bMag = bRing * (5 * kpc / r) * (1 - lfDisk);
b.x += -bMag * sinPhi;
b.y += bMag * cosPhi;
} else {
// spiral region
double r_negx = r * exp(-(phi - M_PI) / tan90MinusPitch);
if (r_negx > rArms[7])
r_negx = r * exp(-(phi + M_PI) / tan90MinusPitch);
if (r_negx > rArms[7])
r_negx = r * exp(-(phi + 3 * M_PI) / tan90MinusPitch);
for (int i = 7; i >= 0; i--)
if (r_negx < rArms[i])
bMag = bDisk[i];
bMag *= (5 * kpc / r) * (1 - lfDisk);
b.x += bMag * (sinPitch * cosPhi - cosPitch * sinPhi);
b.y += bMag * (sinPitch * sinPhi + cosPitch * cosPhi);
}
}
// toroidal halo field
double bMagH = exp(-fabs(pos.z) / z0) * lfDisk;
if (pos.z >= 0)
bMagH *= bNorth * (1 - logisticFunction(r, rNorth, wHalo));
else
bMagH *= bSouth * (1 - logisticFunction(r, rSouth, wHalo));
b.x += -bMagH * sinPhi;
b.y += bMagH * cosPhi;
// poloidal halo field
double bMagX;
double sinThetaX, cosThetaX;
double rp;
double rc = rXc + fabs(pos.z) / tanThetaX0;
if (r < rc) {
// varying elevation region
rp = r * rXc / rc;
bMagX = bX * exp(-1 * rp / rX) * pow(rp / r, 2.);
double thetaX = atan2(fabs(pos.z), (r - rp));
if (pos.z == 0)
thetaX = M_PI / 2.;
sinThetaX = sin(thetaX);
cosThetaX = cos(thetaX);
} else {
// constant elevation region
rp = r - fabs(pos.z) / tanThetaX0;
bMagX = bX * exp(-rp / rX) * (rp / r);
sinThetaX = sinThetaX0;
cosThetaX = cosThetaX0;
}
double zsign = pos.z < 0 ? -1 : 1;
b.x += zsign * bMagX * cosThetaX * cosPhi;
b.y += zsign * bMagX * cosThetaX * sinPhi;
b.z += bMagX * sinThetaX;
return b;
}
void ParticleState::setDirection(const Vector3d &dir) {
direction = dir / dir.getR();
}