Technique for accurately measuring the stopping cross sections of reactive metals by ion back-scattering: He ions in erbium

Journal Article · Sat Dec 01 04:00:00 EST 1973 · Thin Solid Films

DOI:https://doi.org/10.1016/0040-6090(73)90054-0· OSTI ID:4306884

Langley, R. A.; Blewer, R. S.

From international conference on ion beam surface layer analysis; Yorktown Heights, NY (18 Jun 1973). Measurements of the absolute stopping cross sections of reactive metals were made by ion back-scattering using in situ film deposition. The success of the method rests on the dual features of an absence of impurities in the film (particularly oxygen) and the measurement of the target areal density to a high degree of accuracy in the vacuum. Contamination was minimized by vacuum depositing the reactive metal onto the target substrate in an ultrahigh vacuum chamber attached to the beam line of a 2.5 MeV Van de Graaff accelerator. In addition, two independent quartz microbalances built into the substrate holder provided accurate measurements of the film areal density. Using this technique, the stopping cross sections for helium ions in erbium were determined from 250 keV to 2.5 MeV; these cross sections were used to determine the parameters for the analytic expression for the electronic stopping cross section formula developed by D. K. Brice. The values of the parameters are: Z = 2.997, a = 0.3197 and n = 3.168.

• Research Organization: Sandia Labs., Albuquerque, NM
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-027642
• OSTI ID: 4306884
• Journal Information: Thin Solid Films, Journal Name: Thin Solid Films Journal Issue: 2 Vol. 19; ISSN 0040-6090
• Publisher: Elsevier
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*ERBIUM-- ION COLLISIONS
*HELIUM IONS-- STOPPING POWER
BACKSCATTERING
CROSS SECTIONS
N60100* --Physics (Atomic & Molecular)--Atomic
Electron
Ion & Molecular Beams & Reactions
N72100 --Physics (Radiation & Shielding)--Radiation Physics