3d_magnetron

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3d_magnetron

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{ 3D_MAGNETRON.PDE

 MODEL OF A GENERIC MAGNETRON IN 3D

 

 The development of this model is

 described in the Magnetostatics chapter

 of the Electromagnetic Applications

 section.

 

}

 

TITLE 'Oval Magnet '

 

COORDINATES

 CARTESIAN3

 

SELECT

 ngrid=25

alias(x) = "X(cm)"

alias(y) = "Y(cm)"

alias(z) = "Z(cm)"

 

VARIABLES

 Ax,Ay   { assume Az is zero! }

 

DEFINITIONS

 MuMag=1.0 ! Permeabilities:

 MuAir=1.0

 MuSST=1000

 MuTarget=1.0

 Mu=MuAir ! default to Air  

 MzMag = 10000   ! permanent magnet strength

 Mz = 0       ! global magnetization variable

 Nx = vector(0,Mz,0)

 Ny = vector(-Mz,0,0)

 

 B = curl(Ax,Ay,0) ! magnetic induction vector

 Bxx= -dz(Ay)

 Byy= dz(Ax) ! unfortunately, "By" is a reserved word.

 Bzz= dx(Ay)-dy(Ax)

 

EQUATIONS

 Ax:   div(grad(Ax)/mu+Nx) = 0

 Ay:   div(grad(Ay)/mu+Ny) = 0

 

EXTRUSION

  SURFACE "Boundary Bottom"     Z=-5

  SURFACE "Magnet Plate Bottom"    Z=0

    LAYER "Magnet Plate"

  SURFACE "Magnet Plate Top"    Z=1

    LAYER "Magnet"

  SURFACE "Magnet Top"      Z=2

  SURFACE "Boundary Top"     Z=8

 

BOUNDARIES

Surface "boundary bottom" value (Ax)=0 value(Ay)=0

Surface "boundary top" value (Ax)=0 value(Ay)=0

 

REGION 1     {Air bounded by conductive box }

    START (20,-10)

    value(Ax)=0 value(Ay)=0

    arc(center=20,0) ANGLE=180

    Line TO (-20,10)

    arc(center=-20,0) ANGLE=180

      LINE TO CLOSE

 

LIMITED REGION 2     { Magnet Plate }

    LAYER "Magnet Plate" Mu=MuSST

    LAYER "Magnet" Mu=MuMag  Mz = MzMag

    START (20,-8)

      ARC(center=20,0) ANGLE=180

      LINE TO (-20,8)

      ARC(center=-20,0) ANGLE=180

      LINE TO CLOSE

 

  LIMITED REGION 3     { Inner Gap  }

    LAYER "Magnet"

    START (20,-6)      

      ARC(center=20,0) ANGLE=180

      LINE TO (-20,6)

      ARC(center=-20,0) ANGLE=180

      LINE TO CLOSE

 

  LIMITED REGION 4     {Inner Magnet }

    LAYER "Magnet" Mu=MuMag  Mz = -MzMag

    START (20,-2)

      ARC(center=20,0) ANGLE=180

      LINE TO (-20,2)

      ARC(center=-20,0) ANGLE=180

      LINE TO CLOSE

 

MONITORS

grid(y,z) on x=0

grid(x,z) on  y=0

grid(x,y) on  z=1.01

contour(Ax) on x=0

contour(Ay) on y=0

 

PLOTS

grid(y,z) on x=0

grid(x,z) on y=0

grid(x,y) on z=1.01

contour(Ax) on x=0

contour(Ay) on y=0

vector(Bxx,Byy) on z=2.01 norm

vector(Byy,Bzz) on x=0 norm

vector(Bxx,Bzz) on y=4 norm

contour(magnitude(Bxx,Byy,Bzz)) on z=2

 

END