HR: 1330h
AN: P52A-0480    [PDF]
TI: Hugoniot measurements using 15 J laser-propelled flyer sheets
AU: * Kadono, T
EM: kadono@jamstec.go.jp
AF: Japan Marine Science and Technology Center, Natsushima 2-15, Yokosuka, 237-0061 Japan
AU: Sugita, S
EM: sugita@eps.s.u-tokyo.ac.jp
AF: University of Tokyo, Hongo 7-3-1, Bunkyo, 113-0013 Japan
AU: Igarashi, G
EM: iga@eqchem.s.u-tokyo.ac.jp
AF: University of Tokyo, Hongo 7-3-1, Bunkyo, 113-0013 Japan
AU: Matsui, T
EM: matsui@k.u-tokyo.ac.jp
AF: University of Tokyo, Hongo 7-3-1, Bunkyo, 113-0013 Japan
AB: Flyer acceleration facilities with a high intensity laser, "laser gun", have been developed for the past two decades mainly in the field of high-pressure physics. Also in planetary science, laser guns should have some advantages, comparing to conventional guns such as powder guns and two-stage light-gas guns. First, the experiments with laser guns can be carried out under cleaner conditions because there is no gas from explosives. Second, the experiments can be carried out with a short time interval (every 30 minutes); a dozen of shots can be easily done within a day. Third, a high-intensity laser gun can achieve flyer-velocities higher than the escape velocity of Earth, 11.2 km/s, which is not achieved using powder or two-stage light-gas guns. We develop a flyer acceleration facility using a glass laser of University of Tokyo with an maximum energy of 15 J, a pulse width of 15 ns, a spot diameter of 700 $\mu$m, and an intensity of about 100 GW/cm2. Aluminum (Al) sheets with a thickness of 50 $\mu$m, which are attached to a glass base by adhesive, are irradiated. Vapor of Al and adhesive pushes the Al sheets to high velocities. At present, the flyer velocity is up to about 3 km/s due to the small intensity. Using this gun, we perform measurements of the Hugoniot equation of state. Flyer velocity and shock speed in a sample are measured simultaneously with a high-speed camera, and pressure and particle velocity in the sample are estimated by the impedance matching method. Here, as a sample, we use a meteorite (an ordinary chondrite, ALH769) and Hugoniot data are obtained. It should be noted that this measurement system can be used when a laser is upgraded and flyer velocity achieves more than 10 km/s.
DE: 5400 PLANETOLOGY: SOLID SURFACE PLANETS
DE: 5420 Impact phenomena (includes cratering)
DE: 5460 Physical properties of materials
DE: 5494 Instruments and techniques
DE: 6240 Meteorites and tektites
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting