10.101 SPEEDBUMP—Simulates a semi-circular protuberance from one or both walls of the chamber.

Simulates a semi-circular protuberance from one or both walls of the chamber.
Parallel capable? : yes
GPU capable? : no
Back-tracking capable? : no






Parameter NameUnitsType Default

Description






L M double 0.0

insertion length






CHORD M double 0.0

z length of speed bump






DZCENTER M double 0.0

z center displacement of speed bump relative to middle of object






HEIGHT M double 0.0

height above the surrounding chamber






POSITION M double 0.0

position of peak relative to ideal trajectory






DX M double 0.0

horizontal misalignment






DY M double 0.0

vertical misalignment






INSERT_FROM STRINGNULL

direction from which inserted (x, +x, -x, y, +y, -y)






GROUP string NULL

Optionally used to assign an element to a group, with a user-defined name. Group names will appear in the parameter output file in the column ElementGroup






This element simulates a commonplace type of aperture restriction, consisting of a bump on one or both sides of a chamber. The parameters of the speedbump are illustrated in Fig. 4 It may be useful to know that the radius R of the cylinder from which the speedbump is made is

    C2-+-4h2-
R =    8h    ,
(160)

where C is the chord length and h is the bump height. Solving for h, we have

        ∘ -----(---)2-
h = R -   R2 -   C-  .
                 2
(161)


PIC

Figure 4: Illustration of the parameters used in specifying a speedbump.


SREFFECTS