starship-design: Fwd: Antimatter as a Power Source

["L. Parker" <lparker@cacaphony.net>]

Antimatter as a Power Source

Besides being used as tools to check the validity of current theories, 
antiprotons and antihydrogen also could be used for other applications. 
Because of the 100 percent conversion into energy when matter <Picture>and 
antimatter meet, very small amounts of antimatter could produce very large 
amounts of energy. Conceivably, an antimatter fueled power source could be 
very compact, and very powerful. However, Holzscheiter does not see this 
happening with our current technology or understanding of physics. "What is 
needed are fundamentally new ideas on how to handle it [antimatter], how to 
convert it into energy, how to use it," he says.

However, plans already are being formulated to use antiprotons in space 
propulsion systems. One of the early U.S. space shuttle astronauts, Ernst 
Messerschmidt of the Space Research Institute in Stuttgart, Germany, is 
pursuing the use of antiprotons as a heating agent for a plasma drive. 
Antiprotons would be injected into a cloud of charged particles (a plasma) 
confined by a magnetic field. The interaction between the antimatter and 
matter would generate an increased temperature, which converts to an output 
of energy for space applications. Messerschmidt is ready to set up a small 
experiment at CERN, as soon as the antiproton beam becomes available, to 
see how efficiently the process works.

Another propulsion scheme, antiproton catalyzed microfission/fusion (ACMF), 
has been proposed by Smith of Penn State, and others. ACMF involves putting 
short bursts of antiprotons into a fissionable material (e.g., uranium). 
The induced temperature increase would be high enough to induce ignition of 
a hydrogen fusion burn within a microcapsule. (A microcapsule is about the 
size of a BB, and contains hydrogen as a high-pressure gas or liquid. 
Microcapsules are used in fusion research.) For a 130-day round trip to 
Mars--with a 30-day stay--Smith figures ACMF would require about a 
microgram of antiprotons or antihydrogen--about a year's production of 
antiprotons at Fermilab. The cost of the antimatter would be about $50 
million, he says. A spacecraft has been designed around an ACMF engine, and 
a demonstration of ACMF is planned.<Picture>

The key question for any application dreamed up by scientists is what 
amount of antimatter will be needed? According to Rolf Landua, a physicist 
at CERN and a member of the ATHENA team, "It is quite absurd right now to 
talk about macroscopic applications, because all the antimatter that has 
been produced in the past 10 years at CERN is about one nanogram [a 
billionth of a gram]." He estimates that to produce a milligram with CERN's 
present technology would take about a million years and cost about $100 
trillion (without inflation). However, Smith of Penn State points out that 
with new technology, producing a milligram of antimatter would take "about 
10 years and cost $1 to $2 billion."

Lee