[vansig]

closeness and length of time at that distance would both seem to be needed

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desired properties include:
* high melting point
* high electrical conductivity
* high thermal conductivity
* low neutron absorption cross-section
* low xray absorption cross-section
* good stability in vacuum

lithium melting point is quite low. anything exposed to the plasma is going to get to over 1000° C.
heavy elements would absorb a lot of xray.
wouldn’t hydrides bleed off their hydrogen when you put them in vacuum?

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i am hoping that the EMdrive concept has merit, because i am fed up with rocketry.

in terms of rocketry, though, focus fusion might lead to a low-thrust, high specific impulse thruster.

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thickness of an aluminum layer would determine its conductivity, and xrays will scatter as they knock electrons off. the electrons will get thrown in the general direction of the xray’s momentum. i suppose this scattering through several layers could be simulated.

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yes how did the bake-out go?

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Let’s step out from the meta-discussion about whether you can prove stuff mathematically to ask, “can you prove it with science?” because you cant show whether a single particle does or does not induce cancer. but magnitudes of radiation are a significant matter. please study this chart,

https://xkcd.com/radiation/

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hrm, ok i think qikr.co is down; i’ll try to dig up the image…

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Zara, what’s going on? I am having a hard time deciphering your posts

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oldjar wrote:

Here is a link to a video on Chernobyl 20+ years after the accident. The take home message I got was that dangerous levels of radiation remain many years after the release of radioactive elements. Similar problems will be present in Fukushima, Japan:

http://topdocumentaryfilms.com/inside-chernobyl/

What are these dangerous levels? What is considered dangerous?

here is a nice chart we should all familiarize ourselves with,
https://xkcd.com/radiation/

[vansig]

there are so many factors.

your basic p + B11 –> 3 alpha + 8.7 MeV is a lot of energy.
the reaction needs at least 50 keV and is best at about 600 keV;
a fraction of your plasma reacts in the pulse;
you want your magnetic fields to be strong enough to inhibit bremsstrahlung losses (gigagauss fields);
you want your exit beam to be tightly focused and heading in the right direction;
you have to keep your plasma hot and your anode cool;
and you have the energy transformation.

all these things need to be optimized systematically

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the following is not a smoking gun, since alternative explanations for the annual modulation were proposed recently, but offers some insight into present searches for dark matter
http://people.roma2.infn.it/~belli/belli_DM2012.pdf

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As far as i know, the origin of any “it wont work” comments about DPF is the hypothesis that bremsstrahlung radiation would cool the plasma too much.
LPP has shown this hypothesis to be false.

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whereas a scheme that depends on favourable external conditions, like solar wind or density & velocity of dark matter, would not suffer this problem

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i’m not going to address “all propellantless propulsion schemes”.

this thing about weakly interacting massive particles isnt a kitchen sink hypothesis. it should be
testable, as it is probable that there be local anisotropy in the force produced by the thruster,
due to fluctuations of density and velocity of the particles near gravity wells.

[vansig]

Good, then. please tell us about this, “globally conservation is theorised to obtain via the proposed Wheeler-Feynman transactional mechanism.” — http://physics.stackexchange.com/questions/5471/is-the-woodward-effect-real/46377#46377

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