Niobium Germanium – 23K Superconductivity (1967-1974) With AFOSR sponsorship, niobium germanium (Nb3Ge) was discovered to be a superconductor in 1973, and for 13 years (until the discovery in 1986 of the cuprate superconductors) it held the record as having the highest critical temperature. Primary investigators D.W. Deis, John R. Gavaler, and W.T. Reynolds published their findings in June 1974 in AFOSR Technical Report 74-0989, while working at Westinghouse Research Labs, Pittsburgh, Pa. In an April 2012 IEEE/ CSC & ESAS European Superconductivity News Forum article on the history of superconductivity research at Westinghouse, AFOSR was singled out for its support in this area. The authors noted that: “Special credit is also due to one government agency, the AFOSR. Since the late 1960s it maintained continuity of support for the relatively fundamental [Westinghouse] work in materials – until the group was sold to Northrop Grumman and even beyond. This was due to the long-term vision of the late Program Director Max Swerdlow (1915-1989) and his successor Harold Weinstock.”41
AFOSR: Pioneering Support for Picosecond Photochemistry (1968-present) With AFOSR funding, techniques and instrumentation were developed for observing the excited states of molecules with nanosecond to picosecond time resolution (10 to 12 seconds). As a result, it became possible to observe broadband absorption spectra in the time scale of electron and proton transfer processes. The observation of short-lived absorption of light photons by excited molecular states was of importance in understanding the dynamics of laser control materials such as those for Q-switching and modelocking. Researchers at TRW Systems Group previously used a Q-switched ruby laser and a laserinduced spark to observe excited singlet states of aromatic compounds on a nanosecond time scale. They extended the time resolution of laser photolysis into the picosecond range by using the second harmonic (530 nm) of a modelocked neodymium glass laser as an excitation source. The broadband monitoring source was the self-phase modulation continuum produced when 530 nm picosecond laser pulses were focused into glass, water, and other optical media. Continuum pulses of picosecond duration and bandwidth of 320 nm to 700 nm were obtained. Using the continuum as a monitoring source, the investigators stigators observed inverse Raman spectra in several molecules s and a shortlived transient absorption in the dye laser molecule Rhodaminehodamine6C. Picosecond photochemical measurements, a program gram funded solely by AFOSR beginning in 1986 (see page 57), were re the basis for Ahmed Zewail’s Nobel Prize in chemistry in 1999. Picosecond lasers have evolved into femtosecond and attosecond d instruments as the lasers have produced shorter and shorter pulses, and are used in photochemistry and photophysics applications.42
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1960s
up the possibility of electrical starting systems for jet engines. Used in aircraft power generation systems, these magnets opened up the possibility of eliminating the complex and troublesome constant speed drive by substituting a power conditioning package. Also, using such powerful permanent magnets made it possible to build the power generator and the starting motor in the same unit, with further significant weight savings. Small electric motors designed with these magnets produced efficiencies of the order of 70 percent compared to 40 percent for conventional motors. This savings, together with the other characteristics previously listed, prompted one manufacturer to bring out a new line of cordless portable hand-held power tools using CoRE permanent magnets.40