Number 224, May 1, 1995 by Phillip F. Schewe and Ben Stein
THE LARGE HADRON COLLIDER (LHC) at CERN will pack less energy than had
been proposed for the Superconducting Super Collider, but it will be the
only machine in the foreseeable future capable of achieving some of the
same scientific goals. Therefore American particle physicists are drawing
up plans (subject to governmental support) whereby they would be involved
in the construction phase of the LHC project and in subsequent experiments.
At the recent American Physical Society meeting in Washington, DC, several
speakers described these plans for doing research at CERN, where an American
presence has been substantial for years; indeed U.S. scientists have regularly
constituted the largest single national contingent at CERN. Some specific
features of the American participation: for the CMS experiment, the prospective
U.S. share (about 25% of the whole) stands at 38 institutions, including
300 physicists. For ATLAS, the other large detector collaboration, the
comparable numbers are 230 physicists at 28 institutions. The U.S. contribution
to the construction phase might consist of building the focusing magnets
for the accelerator. Sid Drell of SLAC headed a subpanel of experts that
advised the Department of Energy; the subpanel recommended last year that
the US scientific community participate in the LHC project. They proposed
yearly support levels rising from a few million dollars in the early years
to tens of millions at the height of construction.
MAN-MADE LIGHTNING BOLTS FOR BREAKING DOWN AND MONITORING WASTE , described
by Dan Cohn of MIT and colleagues at the APS meeting, represent a potential
near- term spinoff of long-term nuclear fusion research. In a pilot-scale
research furnace at MIT, a 10,000-degree plasma, created by passing an
electric current between a pair of graphite electrodes in a nitrogen-filled
gas chamber, has been used to melt waste material (consisting of soil,
metals, combustible materials and sludges) into a lavalike liquid. The
liquid solidifies into a stable black glass which can be safely stored
or even used as a construction material. The process produces no toxic
ash, virtually no dioxin, and less gas emission than traditional incineration
techniques. Furthermore, it has the potential of being more economical
than present techniques. In a separate demonstration at the Hanford Waste
Reservation in Washington, room- temperature electron plasmas selectively
acted upon minute concentrations of hazardous carbon tetrachloride molecules
vacuum-pumped from waste deposits and split them into less stable compounds
that were eventually broken down into carbon dioxide, table salt, water,
and some carbon monoxide. Paul Woskov of MIT described a system that determines
the hard-to-measure temperatures at the center of a furnace by detecting
the high-frequency microwaves that cut through the smoke in the furnace.
David Rhee of MIT discussed a real-time system that continuously monitors
heavy metal emissions in a waste-burning process. The system uses microwaves
to create a high-temperature plasma in the waste gas. The plasma excites
the heavy metals and causes them to emit radiation which reveals their
spectroscopic fingerprints; concentrations as low as 1 ppb can be detected.
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