To create neutrinos, a beam of particles smashes into a target, which is contained in a chamber. The beam enters and exits the chamber (seen here on a carrier frame) through highly resilient metallic windows (the dark disk at the front of the chamber), which must be able to withstand a pummeling from the high-intensity beam. Fermilab researchers are currently testing a titanium alloy for these windows in preparation for an upcoming increase in beam intensity as part of the PIP-II program. Photo: Fermilab