HITS400 Intersection of a track with a cylinder or a plane

CALL GICYL (R,X1,X2,S1,S2,IC,XINT*,SINT*,PZINT*,IFLAG*)

R

( REAL) radius of cylinder in cm;

X1

( REAL) array of 6, (x, y, z, $dx/ds$ , $dy/ds$ , $dz/ds$ ) of $1st$ point;

X2

( REAL) array of 6, (x, y, z, $dx/ds$ , $dy/ds$ , $dz/ds$ ) of $2nd$ point;

S1

( REAL) track length s at $1st$ point;

S2

( REAL) track length s at $2nd$ point;

IC

( INTEGER) type of interpolation:

1

straight line defined as ( Xi(1),Xi(2),Xi(3)) + s ( Xi(4),Xi(5),Xi(6)), where i is 1 or 2 according to which of the two points is inside the cylinder;

2

straight line going from ( X1(1),X1(2),X1(3)) to ( X2(1),X2(2),X2(3));

3

third degree curve with:

_s=Si) &sp;i=1,2

XINT

( REAL) array of 6 x, y, z, $dx/ds$ , $dy/ds$ , $dz/ds$

at intersection point;

SINT

( REAL) S at intersection point;

PZINT

( REAL) $\phi$ , z, $d\phi /dr$ , $dz/dr$ in cylindrical coordinates at intersection point;

IFLAG

( INTEGER) return flag:

0

track does not intersect cylinder;

1

track intersects cylinder.

CALL GIPLAN (YC,X1,X2,S1,S2,IC,XINT*,SINT*,PZINT*,IFLAG*) The arguments have the same meaning than in the previous routine, apart from:

YC

( REAL) y coordinate of plane;

Note: the default accuracy is 10 microns. The value of EPSI (internal variable) must be changed for a better precision.

HITS500