Analysis of Primary Stripper Foils at SNS by an Electron Beam Foil Test Stand
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2015-01-01 |
| Journal | 6th Int. Particle Accelerator Conf. (IPAC’15), Richmond, VA, USA, May 3-8, 2015 |
| Authors | Eric Paul Barrowclough, C. S. Feigerle, Christopher Luck, M. Plum, Robert W. Shaw |
| Citations | 1 |
Abstract
Section titled “Abstract”Diamond foils are used at the Spallation Neutron Source (SNS) as the primary strippers of hydride ions. A nanocrystalline diamond film, typically 17x45 mm with an aerial density of 0.35 mg/cm², is deposited on a corrugated silicon substrate by plasma-assisted chemical vapor deposition. After growth, 30 mm of the silicon substrate is etched away, leaving a freestanding diamond foil with a silicon handle that can be inserted into SNS for operation. An electron beam test facility was constructed to study stripper foil degradation and impact on foil lifetime. The electron beam capabilities include: current up to 5 mA, focused spot size of 0.30 mm², and rastering in the x- and y-directions. A 30 keV and 1.6 mA/mm² electron beam deposits the same power density on a diamond foil as a 1.4 MW beam on SNS target. Rastering of the electron beam can expose a similar area of the foil as SNS beams. Experiments were conducted using the foil test stand to study: foil flutter and lifetime; effects of corrugation patterns, aerial densities, crystal size (micro vs. nano), and boron doping; temperature distributions and film emissivity; and conversion rate of nanocrystalline diamond into graphite.