LHC vacuum chamber dust High Pressure pure water rinse –Developed at CERN for LEP sputtered SCRF NEG Coating –Most likely must be re-applied Nozzles and shear force Installed systems

[1 ] P. Kneisel and B. Lewis, “Advance Surface Cleaning Methods”, Particle Accelerators 53 (1-4) (1996), 97. [2] T. Higo, J. Hong, P. Michelato and M. Fusetti, “SEM Inspection of HPR Nozzles of Four Labs for SC LC”, ILC ASIA Note, [3] E. Cavaliere et al., “High Pressure Rinsing Parameters Measurements”, Physica C 441 (2006), [4] D. Sertore et al, “High Pressure Rinsing System Comparison”, Proc. PAC07, Albuquerque, USA Physica C 441 (2006)

The ILC SCRF Cavity: Higher Order Mode extraction Power Coupler Port Tuner Cryogen fill pipe Field Probe Graphics by Rey. Hori 9 cell 1300 MHz SW cavity Formed, welded niobium sheet 2.4 mm thick 1 m long; 30 kg

IPAC11 Monday 05 September 2011 Marc Ross, Fermilab 4 R Electron Beam Welds ‘End Group’ of the 9 cell sheet metal cavity Gradient Limits in Vertical test: Quench (55%) Field Emission (19%) Q-slope (4%) (Other) Rongli Geng, Jefferson Lab Kenji Saito, KEK The ILC SCRF Cavity (2):

JLAB 12 GeV Upgrade (halfway) Charlie Reece Presented: SRF2011 MOOCA01 Production and Testing Experience with the SRF Cavities for the CEBAF 12 GeV Upgrade, C. Reese et al Vertical Test; 1500 MHz 7 cell Processed using ILC recipe

adhesion molecular interaction, electrostatic interaction, liquid bridges, double layer repulsion, and chemical bonds. : the size and shape of the particle, its electric charge, its insulating characteristics, the nature of the substrate, the roughness and electrical charge of the substrate, the hardness of both the particle and substrate, the relative humidity of the environment, the nature of the surrounding medium, the temperature...

four adhesion forces : 1.van der Waal's forces, 2.capillary forces, 3.electrical double layer forces and 4.electrostatic image forces.

Methods For Particle Removal semiconductor industry: 1.High Pressure Jet Cleaning 2.Snow Cleaning 3.Ice Scrubber Cleaning 4.Ultraviolet - Ozone Cleaning 5.Megasonic Cleaning 6.Isopropyl Alcohol Vapor Displacement 7.Aerosol Jet Cleaning (supersonic aerosol jet) 8.Laser Steam Cleaning (Kneisel and Lewis)

High Pressure Jet Cleaning shear stresses applied by a high velocity water jet must exceed the adhesion forces holding a particle to a substrate. The drag force applied to is proportional to the square of the local fluid velocity and the fluid density removal of smaller particles requires higher pressures, raising concerns that such pressures will damage the substrate. 1.Bardina, (1988), in Particles on Surfaces edit, by K.L.Mittal, R. Gim, et aI., (1995), in Particles on Surfaces, edit. by K.L.Mittal, 379.

Dry Ice nozzle - Reschke

Detlef Reschke| Cleanroom Techniques| July 23rd, 2011 | Page 13 HPR systems at DESY Rinsing cabinet of “old“ DESY HPR system Rinsing cabinet of “new“ DESY HPR system with “plastic” cavity Sketch of “new” DESY HPR system Jets of single-cell HPR system