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[] Air Force pursuing antimatter weapons program,

"Air Force pursuing antimatter weapons Program was touted publicly, then
came official gag order."

Ich fand den Artikel recht lesenswert.
Maximilian von Goetz
ICQ: 157830706

Der Artikel im San Francisco Chronicle:

The U.S. Air Force is quietly spending millions of dollars investigating
ways to use a radical power source -- antimatter, the eerie "mirror" of
ordinary matter -- in future weapons.
The most powerful potential energy source presently thought to be available
to humanity, antimatter is a term normally heard in science-fiction films
and TV shows, whose heroes fly "antimatter-powered spaceships" and do battle
with "antimatter guns."

But antimatter itself isn't fiction; it actually exists and has been
intensively studied by physicists since the 1930s. In a sense, matter and
antimatter are the yin and yang of reality: Every type of subatomic particle
has its antimatter counterpart. But when matter and antimatter collide, they
annihilate each other in an immense burst of energy.

During the Cold War, the Air Force funded numerous scientific studies of the
basic physics of antimatter. With the knowledge gained, some Air Force
insiders are beginning to think seriously about potential military uses -- 
for example, antimatter bombs small enough to hold in one's hand, and
antimatter engines for 24/7 surveillance aircraft.

More cataclysmic possible uses include a new generation of super weapons -- 
either pure antimatter bombs or antimatter-triggered nuclear weapons; the
former wouldn't emit radioactive fallout. Another possibility is antimatter-
powered "electromagnetic pulse" weapons that could fry an enemy's electric
power grid and communications networks, leaving him literally in the dark
and unable to operate his society and armed forces.

Following an initial inquiry from The Chronicle this summer, the Air Force
forbade its employees from publicly discussing the antimatter research
program. Still, details on the program appear in numerous Air Force
documents distributed over the Internet prior to the ban.

These include an outline of a March 2004 speech by an Air Force official
who, in effect, spilled the beans about the Air Force's high hopes for
antimatter weapons. On March 24, Kenneth Edwards, director of the
"revolutionary munitions" team at the Munitions Directorate at Eglin Air
Force Base in Florida was keynote speaker at the NASA Institute for Advanced
Concepts (NIAC) conference in Arlington, Va.

In that talk, Edwards discussed the potential uses of a type of antimatter
called positrons.

Physicists have known about positrons or "antielectrons" since the early
1930s, when Caltech scientist Carl Anderson discovered a positron flying
through a detector in his laboratory. That discovery, and the later
discovery of "antiprotons" by Berkeley scientists in the 1950s, upheld a
1920s theory of antimatter proposed by physicist Paul Dirac.

In 1929, Dirac suggested that the building blocks of atoms -- electrons
(negatively charged particles) and protons (positively charged particles) -- 
have antimatter counterparts: antielectrons and antiprotons. One fundamental
difference between matter and antimatter is that their subatomic building
blocks carry opposite electric charges. Thus, while an ordinary electron is
negatively charged, an antielectron is positively charged (hence the term
positrons, which means "positive electrons"); and while an ordinary proton
is positively charged, an antiproton is negative.

The real excitement, though, is this: If electrons or protons collide with
their antimatter counterparts, they annihilate each other. In so doing, they
unleash more energy than any other known energy source, even thermonuclear

The energy from colliding positrons and antielectrons "is 10 billion times
.... that of high explosive," Edwards explained in his March speech.
Moreover, 1 gram of antimatter, about 1/25th of an ounce, would equal "23
space shuttle fuel tanks of energy." Thus "positron energy conversion," as
he called it, would be a "revolutionary energy source" of interest to those
who wage war.

It almost defies belief, the amount of explosive force available in a speck
of antimatter -- even a speck that is too small to see. For example: One
millionth of a gram of positrons contain as much energy as 37.8 kilograms
(83 pounds) of TNT, according to Edwards' March speech. A simple
calculation, then, shows that about 50-millionths of a gram could generate a
blast equal to the explosion (roughly 4,000 pounds of TNT, according to the
FBI) at the Alfred P. Murrah Federal Building in Oklahoma City in 1995.

Unlike regular nuclear bombs, positron bombs wouldn't eject plumes of
radioactive debris. When large numbers of positrons and antielectrons
collide, the primary product is an invisible but extremely dangerous burst
of gamma radiation. Thus, in principle, a positron bomb could be a step
toward one of the military's dreams from the early Cold War: a so-called
"clean" superbomb that could kill large numbers of soldiers without ejecting
radioactive contaminants over the countryside.

A copy of Edwards' speech onNIAC's Web site emphasizes this advantage of
positron weapons in bright red letters: "No Nuclear Residue."

But talk of "clean" superbombs worries critics. " 'Clean' nuclear weapons
are more dangerous than dirty ones because they are more likely to be used,"
said an e-mail from science historian George Dyson of the Institute for
Advanced Study in Princeton, N.J., author of "Project Orion," a 2002 study
on a Cold War-era attempt to design a nuclear spaceship. Still, Dyson adds,
antimatter weapons are "a long, long way off."

Why so far off? One reason is that at present, there's no fast way to mass
produce large amounts of antimatter from particle accelerators. With present
techniques, the price tag for 100-billionths of a gram of antimatter would
be $6 billion, according to an estimate by scientists at NASA's Marshall
Space Flight Center and elsewhere, who hope to launch antimatter-fueled

Another problem is the terribly unruly behavior of positrons whenever
physicists try to corral them into a special container. Inside these
containers, known as Penning traps, magnetic fields prevent the
antiparticles from contacting the material wall of the container -- lest
they annihilate on contact. Unfortunately, because like-charged particles
repel each other, the positrons push each other apart and quickly squirt out
of the trap.

If positrons can't be stored for long periods, they're as useless to the
military as an armored personnel carrier without a gas tank. So Edwards is
funding investigations of ways to make positrons last longer in storage.

Edwards' point man in that effort is Gerald Smith, former chairman of
physics and Antimatter Project leader at Pennsylvania State University.
Smith now operates a small firm, Positronics Research LLC, in Santa Fe, N.M.
So far, the Air Force has given Smith and his colleagues $3.7 million for
positron research, Smith told The Chronicle in August.

Smith is looking to store positrons in a quasi-stable form called
positronium. A positronium "atom" (as physicists dub it) consists of an
electron and antielectron, orbiting each other. Normally these two particles
would quickly collide and self-annihilate within a fraction of a second -- 
but by manipulating electrical and magnetic fields in their vicinity, Smith
hopes to make positronium atoms last much longer.

Smith's storage effort is the "world's first attempt to store large
quantities of positronium atoms in a laboratory experiment," Edwards noted
in his March speech. "If successful, this approach will open the door to
storing militarily significant quantities of positronium atoms."

Officials at Eglin Air Force Base initially agreed enthusiastically to try
to arrange an interview with Edwards. "We're all very excited about this
technology," spokesman Rex Swenson at Eglin's Munitions Directorate told The
Chronicle in late July. But Swenson backed out in August after he was
overruled by higher officials in the Air Force and Pentagon.

Reached by phone in late September, Edwards repeatedly declined to be
interviewed. His superiors gave him "strict instructions not to give any
interviews personally. I'm sorry about that -- this (antimatter) project is
sort of my grandchild. ...

"(But) I agree with them (that) we're just not at the point where we need to
be doing any public interviews."

Air Force spokesman Douglas Karas at the Pentagon also declined to comment
last week.

In the meantime, the Air Force has been investigating the possibility of
making use of a powerful positron-generating accelerator under development
at Washington State University in Pullman, Wash. One goal: to see if
positrons generated by the accelerator can be stored for long periods inside
a new type of "antimatter trap" proposed by scientists, including Washington
State physicist Kelvin Lynn, head of the school's Center for Materials

A new generation of military explosives is worth developing, and antimatter
might fill the bill, Lynn told The Chronicle: "If we spend another $10
billion (using ordinary chemical techniques), we're going to get better high
explosives, but the gains are incremental because we're getting near the
theoretical limits of chemical energy."

Besides, Lynn is enthusiastic about antimatter because he believes it could
propel futuristic space rockets.

"I think," he said, "we need to get off this planet, because I'm afraid
we're going to destroy it."

E-mail Keay Davidson at kdavidson -!
- sfchronicle -
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