| From : |
Bruno Ogorelec |
| Date : |
2003-07-06 10:18:10 |
| Subject : |
Re:Ion Ramjets? |
Serge wrote :
>Just how much did you think of when you said `a fraction of the speed of light`?
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No clue at the moment. Sorry; haven't been in touch with space issues for ages.
The very fact that many a scientist and engineer has entertained the idea indicates that it is not completely fantastic. The speed at which the mass flow of interstellar 'gas' through your propulsion duct becomes appreciable must not be that fantastically great.
It turns out, however, that I was wrong to claim it's been present in science fiction since the 1930s. I just found out that the idea of an interstellar ramjet was first proposed by Robert Bussard in 1960.
He proposed a craft that scooped the hydrogen of space using a magnetic deflector as its scoop. Inside the craft would be a set of lasers that would ionize the atoms and pulverise the dust picked up. As the speed of the craft increases, the magnetic field is lessened in intensity as the craft's efficiency actually increases with speed.
A site I found on the web (and lost the URL, damn) says that the idea has been criticized.
One critic was Anthony Martin of London City University. He found that some particles would be trapped in the scoop's magnetic field which will radiate some of the energy away as they collide on the way to the reactor.
There will also be incomplete fusion of the hydrogen within the reactor, lessening the efficiency of the system further.
Martin also found that the field strength must increase, not decrease, with speed. Therefore, beyond a certain point, the acceleration would have to be reduced.
The site said nothing about the density of interstellar hydrogen and other matter.
Bruno |
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Re:Ion Ramjets?
( 2003-07-06 10:18:10)