
 PHYSICS NEWS UPDATE
 A digest of physics news items prepared by Phillip F. Schewe, AIP
 Public Information
 Number 151  November 15, 1993

 JOHN PEOPLES WILL OVERSEE THE DISMEMBERMENT OF
 THE SSC while retaining his directorship at Fermilab.  Peoples
 replaces Roy Schwitters, who resigned last week as head of the SSC.
 An estimated $1.5 billion in SSC shutdown money will go largely for
 severance to displaced SSC employees and for settling claims from
 SSC contractors.  (The New York Times, 9 Nov. 1993.)

 DISPOSSESSED AMERICAN PARTICLE PHYSICISTS are looking
 around for alternative research venues.  British science minister
 William Waldegrave has suggested informally that "CERN should
 immediately invite the US in as a member state."  Other countries
 such as Italy and France are not keen on this idea, not wanting the
 US (or Japan) to gain an undue influence over what until now has
 been a European venture.  Stanford scientist Sidney Drell favors the
 creation of a whole new, truly worldwide, Center for International
 Nuclear Research (CIRN).  Short term plans must also be pursued.
 Tom Kirk, who left Fermilab for the SSC, says that some of the
 scientists who worked with him on the Solenoidal Detector
 Collaboration (SDC) at SSC may be able to apply the fruits of their
 efforts (knowledge if not hardware) in some way to the development
 of detectors at the proposed Large Hadron Collider at CERN.
 (Physics World, Nov. 1993.)

 A SELF-FOCUSING LASER has been developed at AT&T Bell
 Labs.  The layered semiconductor device is patterned on top with a
 set of micron-sized concentric grooves, which constitute a sort of
 Fresnel lens. Infrared laser light, emitted from this top face, is
 focused to an 8-micron spot size.  Daryoosh Vakhshoori of Bell Labs
 believes this "zone laser" will promote a better coupling of laser light
 into external optical fibers.  (Science News, 6 Nov. 1993.)

 SOLAR RADIATION VARIES only a few tenths of a percent at
 visible wavelengths over the sun's activity cycle, but varies by as
 much as a factor of 10 at extreme-ultraviolet and x-ray wavelengths.
 Solar UV radiation has an important role in Earth's atmospheric
 chemistry, particularly in the formation of stratospheric ozone.  UV
 rays help to make ozone (from atmospheric oxygen) in the first place;
 then the ozone protects living organisms from harmful effects of the
 UV.  The sun's UV flux, monitored by the Upper Atmospheric
 Research Satellite (UARS), is declining now as the sun passes into the
 less-active part of its 11-year cycle.  By studying the solar UV
 spectrum over short and long periods of time, UARS hopes to provide
 information that can lead to a differentiation between natural and
 anthropogenic sources of ozone variability.  (Physics World, Oct.
 1993.)

 MOLECULAR DYNAMICS (MD) SIMULATIONS have gotten
 faster.  These computer studies track the behavior of a hypothetical
 ensemble of particles subject to a specific law of motion incorporating
 the complex interactions among neighboring particles.  As part of a
 study of supersonic projectiles, scientists at Los Alamos have
 simulated the 3-dimensional movement of 180 million particles, with
 4 updated configurations per microsecond.  Less than a year ago, the
 largest comparable MD simulation tracked 17 million particles.  The
 Los Alamos computer system had a sustained speed of 50 Gigaflops.
 (Physics World, Oct. 1993.)

