CASSINI
Cassini MIMI Investigation at Fundamental Technologies
Numerical Computation of Energy-Dependent Geometric Factors of E and F Electron Detectors of CASSINI/MIMI/LEMMS
Technical Report by Xiaodong Hong and Thomas P. Armstrong, May 10, 1997
******************************************************************************* * * * PROGRAM I.4 * * * ******************************************************************************* * * * TRACKSUB4.FOR * * THIS FILE CONTAINS THE SUBROUTINES THAT EVALUATE THE ENERGY & THE * * VELOCITY COMPONENTS OF THE VELOCITY.ALSO, IT CONTAINS THE SUBROUTINE * * THAT READS THE COORDINATES OF THE VERTICES OF THE PLANE SURFACES AND * * THE PLANE COEFFICIENTS FROM THE FILES AND INITIALISES THE ARRAYS. * * * *******************************************************************************
SUBROUTINE VELOPROJ(V,VX,VY,VZ,THETA,PHI)
C PURPOSE : GIVEN THE VELOCITY, TO FIND THE COMPONENTS OF VELOCITY C IN THE CARTESIAN COORDINATE SYSTEM I.E. TO FIND Vx,Vy,Vz
REAL*8 PHI,PHI1,PI,RAD,THETA,THETA1,V,VX,VY,VZ
PI = 4.0D0 * DATAN(1.0D0) RAD = PI/180.0D0 THETA1 = THETA * RAD PHI1 = PHI * RAD VX = V * DSIN(THETA1) * DCOS(PHI1) VY = V * DSIN(THETA1) * DSIN(PHI1) VZ = V * DCOS(THETA1)
RETURN END
C--------------------------------------------------------------------- C--------------------------------------------------------------------- REAL*8 FUNCTION EVELO(EK)
C PURPOSE : TO FIND THE RATIO OF THE VELOCITY OF THE e TO THE VELOCITY C OF LIGHT. I.E. TO COMPUTE V/C GIVEN THE INITIAL ENERGY OF THE ELECTRON C IN MEV. 2 2 C FORMULA USED : (V/C) = 1 - (REST MASS) C ---------------- 2 C (K.E. + REST MASS)
IMPLICIT NONE REAL*8 C,E1,EK,TEMP DATA C/2.998D0/,E1/0.511D0/
TEMP = E1/(E1+EK) EVELO = C * DSQRT(1 - TEMP*TEMP)
RETURN END
C--------------------------------------------------------------------- C---------------------------------------------------------------------- SUBROUTINE GEOM
C PURPOSE: THIS SUBROUTINE OPENS THE FILES: C COOR*.DAT:IT CONTAINS THE COORDINATES OF ALL THE VERTICES OF ALL THE C PLANE SURFACES THAT THE PARTICLE IS LIKELY TO HIT C COEFF.DAT:IT CONTAINS THE CONSTANT COEFFICIENTS A,B,C,D OF EACH OF THE C PLANES THAT THE PARTILCE IS LIKELY TO HIT C AND IT INITIALISES THE ARRAYS: C CHAN:EACH ROW CORRESPONDS TO A PLANE SURFACE; C COL. 1:NO. OF VERTICES OF THAT PLANE POLYGON C COL. 2>>>COL. NVERT*3+1 :ALL THE COORDINATES OF THE VERTICES C COEFF:EACH ROW CORRESPONDS TO A PLANE POLYGON C COL. 1>>>COL. 4 :A,B,C,D
IMPLICIT NONE CHARACTER*72 FNAME,FNAME1 INTEGER HIT,I,I1,I2,J,K,MAXCOO,MAXSURF,NS,NV,NSURF,NVERT,NTY PARAMETER (MAXCOO=62,MAXSURF=62) REAL*8 A,B,C,D REAL*8 CHAN(MAXSURF,MAXCOO),COEFF(MAXSURF,4),TLN(2,3),VERT(10,3), & Y(6) COMMON /CHAN/CHAN,/TLN/TLN,/COEFF/COEFF,/NTY/NTY
WRITE(6,*) 'ENTER THE NAME OF THE FILE OF COORDINATES' READ(5,10) FNAME OPEN (UNIT=1,STATUS='OLD',FILE=FNAME)
WRITE(6,*) 'ENTER THE NAME OF THE FILE OF COEFFICIENTS' READ(5,10) FNAME1 OPEN (UNIT=2,STATUS='OLD',FILE=FNAME1)
READ (1,*) 2 READ(1,*,END=70) NTY READ(1,*) NVERT CHAN(NTY,1) = DFLOAT(NVERT) I1=2 3 READ(1,20,ERR=2) (CHAN(NTY,K),K=I1,I1+2) I1=K GO TO 3 70 CLOSE(1)
c do i = 1,maxsurf c do j = 1,chan(i,1) c WRITE(6,*) (i) c do k = (j-1)*3+2,(j-1)*3+4 c chan(i,k)=chan(i,k)/2.540005 c end do c write(6,*) (chan(i,k), k=(j-1)*3+2,(j-1)*3+4) c end do c end do
I2=1 4 READ(2,30,END=80) NS,NV,(COEFF(I2,J),J=1,4) C WRITE(6,*)(NS,NV,(COEFF(I2,J),J=1,4)) I2=I2+1 GO TO 4 80 CLOSE(2)
c DO I=1,NTY c WRITE(6,*) 'SURFACE NO.:',I c WRITE(6,*)'COORDINATES ARE:' c WRITE(6,*) (CHAN(I,J),J=2,IDINT(CHAN(I,1))*3+1) c WRITE(6,*) 'THE PLANE COEFFICIENTS ARE:' c WRITE(6,*) (COEFF(I,J),J=1,4) c END DO
10 FORMAT(A72) 20 FORMAT(3(X,F9.6)) 30 FORMAT(1X,I3,1X,I3,4(1X,D13.6))
RETURN END C------------------------------------------------------------------------- C------------------------------------------------------------------------- SUBROUTINE PASSOUTPUT
C PURPOSE:THIS PROGRAM OUTPUTS THE POLAR & THE AZIMUTHAL ANGLES C OF THE ESCAPING PARTICLES ONTO A FILE. C C NPAS : TOTAL NO. OF PARTICLES THAT ESCAPE THE SENSOR ASSEMBLY C PAS(I,J) : 2-D ARRAY C I : NO. OF ESCAPING PARTICLE C J=1 : POLAR ANGLE AT THE DETECTOR C =2 : AZIMUTHAL ANGLE AT THE DETECTOR C =3 : POLAR ANGLE AT THE APERTURE C =4 : AZIMUTHAL ANGLE AT THE APERTURE C =5-10 : X,Y,Z,Vx,Vy,Vz OF THE ESCAPING PARTICLE c =11 : sine of the incident angle c =12 : the number of the plane the particle hits c =13-15: the coordinates of the impact
IMPLICIT NONE CHARACTER*72 FNAME1,FNAME2,FNAME3,FNAME4 INTEGER I,J REAL*8 PASVEL(10000,2),PI,RAD
C COMMON /PASVEL/PASVEL COMMON /FNAME1/FNAME1 COMMON /FNAME4/FNAME4 COMMON /FNAME2/FNAME2,FNAME3 INCLUDE 'PASS5.CMN'
PI = 4.0D0*DATAN(1.0D0) RAD = 180.0D0/PI
OPEN(UNIT=8,FILE=FNAME1,ACCESS='SEQUENTIAL',STATUS='OLD') OPEN(UNIT=1,FILE=FNAME2,ACCESS='SEQUENTIAL',STATUS='OLD') OPEN(UNIT=2,FILE=FNAME3,ACCESS='SEQUENTIAL',STATUS='OLD') C OPEN(UNIT=3,FILE=FNAME4,ACCESS='SEQUENTIAL',STATUS='OLD') WRITE(8,*) 'NPAS:',NPAS write(1,25) WRITE(8,*) WRITE(8,20) DO I=1,NPAS PAS(I,3) = PAS(I,3)*RAD PAS(I,4) = PAS(I,4)*RAD c PASVEL(I,1) = PASVEL(I,1)*RAD c PASVEL(I,2) = PASVEL(I,2)*RAD WRITE(8,10) (PAS(I,J),J=1,10) if (pas(i,11).eq.0) then WRITE(1,50) PAS(I,1),PAS(I,2) else WRITE(1,40) PAS(I,1),PAS(I,2),(pas(i,j),j=11,15) end if WRITE(2,30) PAS(I,3),PAS(I,4) c WRITE(3,30) PASVEL(I,1),PASVEL(I,2) END DO
10 FORMAT(1X,4(F7.2,X),6(D15.8,X)) 20 FORMAT (1X,' THETA ',1X,' PHI ',1X,' OMEGA ',1X,' PSI ', & X,6X,'X(+02)',3X,X,6X,'Y(+02)',3X,X,6X,'Z(+02)',3X,X,4X, & 'VX(+10)',4X,X,4X,'VY(+10)',4X,X,4X,'VZ(+10)',4X) 25 format(1x,' Theta',1x,' Phi ',1x,'Sin(a) ',1x,'Plane ',1x, & ' X ',1x,' Y ',1x,' Z ') 30 FORMAT(2(X,F9.3)) 40 format(4(x,f7.2),3(x,d10.3)) 50 format(2(x,f7.2)) RETURN END C---------------------------------------------------------------------------- C---------------------------------------------------------------------------- REAL*8 FUNCTION FPHI(XT,YT) C IMPLICIT NONE REAL*8 PI,TOL,XT,YT PARAMETER (TOL=0.1D-10) D PRINT *,'TOL: ',TOL PI=4.0D0*DATAN(1.0D0)
IF (DABS(XT).LT.TOL .AND. YT.GT.0.0D0) THEN FPHI=PI/2.0D0 D PRINT *,'I AM IN 1' ELSE IF (DABS(XT) .LT. TOL .AND. YT.LT.0.0D0) THEN FPHI=1.5D0*PI D PRINT *,'I AM IN 2' ELSE IF (XT.GT.0.D0.AND.YT.GE.0.0D0) THEN FPHI=DATAN(YT/XT) D PRINT *,'I AM IN 3' ELSE IF (XT.LT.0.0D0.AND.YT.GE.0.D0) THEN FPHI=PI-DATAN(YT/DABS(XT)) D PRINT *,'I AM IN 4' ELSE IF (XT.LT.0.D0.AND.YT.LE.0.0D0) THEN FPHI=PI+DATAN(YT/XT) D PRINT *,'I AM IN 5' ELSE FPHI=2*PI-DATAN(DABS(YT)/XT) D PRINT *,'I AM IN 6' END IF END IF END IF END IF END IF RETURN END C------------------------------------------------------------------------
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Updated 8/8/19, Cameron Crane
QUICK FACTS
Manufacturer: The Cassini spacecraft
was manufactured by NASA's Jet Propulsion Laboratory,
and the Huygens Probe was manufactured by Thales Alenia
Space.
Mission Duration: The Cassini-Huygens mission launched on October 15 1997, and ended on September 15 2017.
Destination: Cassini's destination was Saturn and its moons. The destination of the Huygens Probe's was Saturn's moon Titan.
Orbit: Cassini orbited Saturn for 13 years before diving between its rings and colliding with the planet on September 15th, 2017.
Mission Duration: The Cassini-Huygens mission launched on October 15 1997, and ended on September 15 2017.
Destination: Cassini's destination was Saturn and its moons. The destination of the Huygens Probe's was Saturn's moon Titan.
Orbit: Cassini orbited Saturn for 13 years before diving between its rings and colliding with the planet on September 15th, 2017.