General Physical Aperture

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marlibgin
Posts: 54
Joined: 15 Mar 2011, 12:43

General Physical Aperture

Post by marlibgin » 19 Sep 2022, 09:12

I have so far been using aperture_data to define physical apertures. Just to be sure, this command defines completely decoupled horizontal and vertical planes. In other terms, the H-V physical limitations can be regarded a a rectangular beam pipe.
Questions:
- is there a way to define an elliptical vacuum chamber?
- for non-cylindrical cases, or rather, for completely general cases, is obstruction_data (in floor coordinates) the only option available? in this case is there an example available?

thanks,
Marco

michael_borland
Posts: 1797
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
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Re: General Physical Aperture

Post by michael_borland » 19 Sep 2022, 15:26

Marco,

There are many ways to define apertures in elegant, each with advantages and disadvantages.

You can use various beamline elements
  • APCONTOUR defines an aperture an (x, y) contour. The aperture can be localized or can be applied to downstream elements.
  • ECOL defines an elliptical (or superelliptical) collimator, with an optional open side.
  • MAXAMP defines an elliptical or rectangular aperture that persists on and inside downstream elements.
  • RCOL defines a rectangular collimator, with an optional open side.
  • SCRAPER defines a one-sided aperture.
  • SPEEDBUMP defines a one- or two-sided aperture with a cylindrical longitudinal profile.
  • Tapered apertures of various shapes can be defined with TAPERAPC, TAPERAPE, and TAPERAPR.
Of these, APCONTOUR is probably the most versatile and easy way to define complex apertures.

There are also two commands for defining apertures, which you know about:
  • The aperture_data command allows providing x and y apertures vs s, but is restricted to rectangular boundaries.
  • The obstruction_data command allows providing (z, x) contours at various y values and is fully general, but can be hard to set up.
--Michael

marlibgin
Posts: 54
Joined: 15 Mar 2011, 12:43

Re: General Physical Aperture

Post by marlibgin » 20 Sep 2022, 09:22

Thank you very much Michael
Marco

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