Advanced Collimator Ideas Josef Frisch
Advanced Collimators The NLC beam energy density is sufficient to destroy any solid object. Without interception at r25m from the beam the electric field is destructive. Peak E Field Induced Currents Electro-dynamic stresses
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
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
Schematic Collimator Layout
Solidifying collimator concept
Vertical Collimation more complex Liquid metal pumps used for soldering systems Chamber heated, rollers cooled
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
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
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
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.