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Trapped Radiation ENvironment model Development

UD330

[ Name | Synopsis | Arguments | Description | Diagnostics | Common Blocks | Dependencies | See Also | Reported Bugs | Examples ]

Name

    Subroutine UD330 - evaluate the third invariant

Synopsis

      REAL*8        phi,star
      INTEGER*4     ifail
      
      CALL UD330 (phi, star, ifail)

Arguments

    phi
    Third invariant [out]
    star
    Roederer's shell parameter L* [out]
    ifail
    Error flag (passed by dependents) [out]

Description

    The subroutine UD330 computes the third invariant of the magnetic drift shell stored in the common block UC110, UC120 and UC130. The third invariant is evaluated by the integration of the magnetic flux over a spherical polar cap. Note that the subroutine needs the foot prints of the magnetic field lines contained in the drift shell. To this effect, the argument falt has to be set to a positive value when the subroutine UD310 is called to build the drift shell. The integration steps are controlled by the arguments epsomeg and dltlat of the common block UC192.

    Roederer's shell parameter L* is deduced directly from the value of the third invariant and of the moment M of the magnetic dipole. The value of M depends on the argument kmflg of the common block UC190.

References

  • Roederer, J.G., Dynamics of geomagnetically trapped radiation, Springer-Verlag (1970)

Diagnostics

    None

Common Blocks

    UC110, magnetic drift shell description
    UC140, magnetic field description
    UC160, general constants
    UC190, control parameters, set 1

Dependencies

Called by

    None

Calls

    UD331, evaluate the magnetic flux through a spherical cap

See also

    UL240, evaluate the Hilton's function
    UD310, trace a magnetic drift shell

Reported Bugs

    None

Examples

    #3, evaluation of the third invariant
    T.04 Why are Roederer's L* and McIlwain's L parameters different ?