Advanced Collimator Ideas

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Advanced Collimator Ideas

• Josef Frisch

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Advanced Collimators

• The NLC beam energy density is sufficient to
  destroy any solid object.
• Without interception at r?25?m from the beam the
  electric field is destructive.
• Peak E Field
• Induced Currents
• Electro-dynamic stresses

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Collimator types

• Single use Collimators are replaced if damaged
  Standard Jaws / Apertures
• Multi use Collimators designed to be damaged
  multiple times Rotating wheels, tapes.
• Indestructible Collimators which can be repaired
  after each shot Liquid, Exotic

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Types of Indestructible Collimators

• Flowing liquid Jets, waves Indestructible, but
  tolerances are difficult. (Should study jet
  stability)
• Liquid film / Solidifying Might have good
  tolerances, but limited film thickness.
• Exotic Lasers, etc No practical designs

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Schematic Collimator Layout
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Solidifying collimator concept
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Vertical Collimation more complex

• Liquid metal pumps used for soldering systems
• Chamber heated, rollers cooled

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Liquid Collimator Materials

• Need low vapor pressure at melting point
• Need low activation
• Need to wet surface without corrosion
• Need ductile solid state to allow rolling for
  film thickness control.
• Material study needed

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Technical issues

• Properties of thin solidified films
• Ductility, surface finish
• High temperature, radiation resistant, UHV
  mechanics many complex problems
• Surface chemistry between metal film and roller
  Adhesion, corrosion, film thickness
• System so far is only a design concept

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Research Plan

• Paper study of possible collimator materials
• Vacuum test chamber for testing films
• Optical monitor of film thickness
• Optical monitor of film roughness
• Optional pulsed laser for beam simulation
• Add rollers / scrapers to the test chamber
• Measure ductility / rolled surface finish

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Collimator design status

• No developed solution to the problem
• Basic materials tests for solidifying film
  collimator concept needed before detailed design
  can be done
• Is there industrial experience Soldering is a
  different process - involves the formation of
  intermetallic compounds.