Havar® Foil (Light Tight)

Havar® (UNS R30004) light-tight foil is a pinhole-free, precision-grade cobalt-chromium alloy (Co 42%, Cr 20%, Ni 13%, Fe 19%, Mo 4%, W 2.8% (wt%), density 8.3 g/cm³) specifically manufactured and verified for applications requiring hermetic sealing, gas-tight barriers, or complete freedom from microscopic defects. Each foil undergoes rigorous optical backlight inspection to ensure zero pinholes, making it the preferred choice for vacuum chamber entrance windows in particle physics experiments where even microscopic leaks compromise experimental conditions, sealed radiation source encapsulations requiring absolute containment, and critical medical isotope production systems where target integrity is paramount. With tensile strength of 1380-1725 MPa and available in thicknesses from 5 to 500 microns, light-tight Havar foil provides the same exceptional radiation transparency, non-magnetic properties (ur ≈ 1), and corrosion resistance as standard Havar® while guaranteeing hermetic performance for ultra-high vacuum systems, detector windows requiring gas containment, and applications where even single-pinhole failures are unacceptable. The material maintains dimensional stability from -196°C to +400°C, exhibits low outgassing (<10⁻¹⁰ torr·L/(s·cm²)) after vacuum baking, and can be welded by electron beam or laser methods for creating sealed assemblies. Light-tight foil is supplied with protective interleaving acid-free packaging to prevent damage or contamination during handling, complete with chemical composition analysis, and mechanical property verification, ensuring the highest reliability for demanding nuclear physics, vacuum technology, and precision sensing applications where hermetic integrity is non-negotiable.