1. RF Absorption Measurements from Beam Pipe Coatings
Alexander Brown
Allegheny College, Meadville, PA
Yulin Li & Valery Shemelin
Cornell University, Ithaca, NY

2. Non-Evaporable Getter Coating
Gas Sources in Accelerator Vacuum Chambers
Thermal Outgassing
Accelerator Vacuum Pumping
Lumped Pumping
Distributed Pumping
Total Pumping
NEG Coating
November 15, 2018November 15, 2018
Cornell LEPP Template

3. Deposition of NEG Thin Films
Typical Sputtering Setup
Cathode – Twisted wires
Electric field (ion energy) ~ 600 V
Magnetic field : ~ 500 Gauss
Sputtering gas : Ar or Kr P = 2 ~ 20 mtorr
November 15, 2018November 15, 2018
Cornell LEPP Template

4. RF Absorption Measurements
RF properties up to very high frequencies may have impact to short bunch electron performance
RF absorption measurements of the NEG coating will be done with coated ceramic samples ,
f, GHz
Dim’s of w/g, 0.001inches (mils)
Max f, GHz
/2 (mm) Max. Thickness
620 x 310 18
2.671
18 – 26.5
420 x 170
26.5
1.814
280 x 140 40
1.202 ,
November 15, 2018November 15, 2018
Cornell LEPP Template