Page 6 of 59

Posted: Tue Apr 27, 2010 4:56 am
by zapkitty
jrvz wrote: High energy particles are deflected by magnetic fields, but in the process they emit synchrontron radiation http://en.wikipedia.org/wiki/Synchrotron_radiation. These are X or gamma rays, primarily forward along the particle's original path (like headlights). Maybe the resulting radiation dose is too small to require shielding, but I'm surprised the article doesn't even mention it.
Even with energy shields it seems that the hull of the ship (or at least the hab module) will require some passive shielding. My thought was a thin layer of lead backed by boron. It's the only way to be sure :)

The heavy shielding of the storm shelter would be for shield failure during an SPE etc...

... locked-room mystery... power failure in close orbit around Jupiter... the storm shelter will protect you from the Jovian radiation belts... but how do you get out long enough to make repairs and leave orbit?

Posted: Tue Apr 27, 2010 5:00 am
by Brian H
zapkitty wrote:
jrvz wrote: High energy particles are deflected by magnetic fields, but in the process they emit synchrontron radiation http://en.wikipedia.org/wiki/Synchrotron_radiation. These are X or gamma rays, primarily forward along the particle's original path (like headlights). Maybe the resulting radiation dose is too small to require shielding, but I'm surprised the article doesn't even mention it.
Even with energy shields it seems that the hull of the ship (or at least the hab module) will require some passive shielding. My thought was a thin layer of lead backed by boron. It's the only way to be sure :)

The heavy shielding of the storm shelter would be for shield failure during an SPE etc...

... locked-room mystery... power failure in close orbit around Jupiter... the storm shelter will protect you from the Jovian radiation belts... but how do you get out long enough to make repairs and leave orbit?
The short straw system.

Posted: Tue Apr 27, 2010 1:40 pm
by clonan
zapkitty wrote: ... locked-room mystery... power failure in close orbit around Jupiter... the storm shelter will protect you from the Jovian radiation belts... but how do you get out long enough to make repairs and leave orbit?
Teleoperated Robots...

Posted: Tue Apr 27, 2010 2:53 pm
by Aeronaut
zapkitty wrote:
jrvz wrote:
... locked-room mystery... power failure in close orbit around Jupiter... the storm shelter will protect you from the Jovian radiation belts... but how do you get out long enough to make repairs and leave orbit?
Design with 2 reactors.

Posted: Tue Apr 27, 2010 8:39 pm
by Skipjack
There is another LPP update on Nextbigfuture:
http://nextbigfuture.com/2010/04/lawren ... .html#more
In all three cases, Ti exceeds 40 keV, and in the best shot it exceeds 65 keV. [...]
For comparison, ion energies of around 100 keV will be enough to ignite pB11 fuel, given adequate density
Nothing groundbreakingly new, but they do seem to be making progress.

Posted: Wed Apr 28, 2010 2:36 am
by Aeronaut
Skipjack wrote:There is another LPP update on Nextbigfuture:
http://nextbigfuture.com/2010/04/lawren ... .html#more
In all three cases, Ti exceeds 40 keV, and in the best shot it exceeds 65 keV. [...]
For comparison, ion energies of around 100 keV will be enough to ignite pB11 fuel, given adequate density
Nothing groundbreakingly new, but they do seem to be making progress.
On track, all information good.

LPP's confirming the Texas A&M scaling experiments on a full-sized machine, which now seems to be duplicating the ion temperatures on a little over half the current.

Peak current is directly related to peak field strength and the high magnetic field effect that is expected to keep bremstrahlung in a range we can live with.

Posted: Wed Apr 28, 2010 5:43 am
by Betruger
Good to hear the straight dope from you guys. Hope to hear news by year's end.. Best of luck.

Posted: Wed Apr 28, 2010 11:12 am
by Aeronaut
Betruger wrote:Good to hear the straight dope from you guys. Hope to hear news by year's end.. Best of luck.
Our pleasure, Betruger. We're hoping for one helluva New Year's party around the world this year.

Posted: Wed Apr 28, 2010 12:34 pm
by Kahuna
More detail on high-energy ion production and collection/measurment methodology here: http://focusfusion.org/assets/pdf/LPP_TR2_Apr_2010.pdf

KAHUNA

Posted: Wed Apr 28, 2010 4:16 pm
by Brian H
kurt9 wrote:
Giorgio wrote:I am still convinced that the Polywell has a more sound physics in respect to LPP hypothesis. Yet I have to take my hat off to the accomplishments and openness of LPP people.

They are burning the ground in their experiments, and if Eric Lerner is right they might beat anyone else to accomplish Fusion.
Yes, this is good. It would be kiss-ass if they were sucessful.
:shock: :lol: I HOPE you mean "kick-ass"!! :P

New news: 1 MA, Simultaneity, Simulation, etc.

Posted: Wed May 05, 2010 4:19 pm
by Brian H

Posted: Wed May 05, 2010 7:04 pm
by Skipjack
Interesting. I guess they are on track. Though they will have to replace the electrodes, which will - from what I understand- result in a delay?
Still, it is nice to see frequent updates on their research. It makes it much more tangible. I wished we had that frequent updates from Dr. Nebel and co.

Posted: Wed May 05, 2010 10:53 pm
by Brian H
Skipjack wrote:Interesting. I guess they are on track. Though they will have to replace the electrodes, which will - from what I understand- result in a delay?
Still, it is nice to see frequent updates on their research. It makes it much more tangible. I wished we had that frequent updates from Dr. Nebel and co.
AFAIK, the only electrode replacements are those which will be required for different gas mixtures and different energy regimes. The new firing "pins" in the switches are to replace the old standard spark-plugs, which were causing timing problems.

Posted: Wed May 05, 2010 11:05 pm
by Skipjack
Duh, yeah, sorry, I should not be doing so many things at once. I wanted to say spark plugs. Sigh...

Posted: Fri May 07, 2010 4:24 pm
by TallDave
clonan wrote:
zapkitty wrote: ... locked-room mystery... power failure in close orbit around Jupiter... the storm shelter will protect you from the Jovian radiation belts... but how do you get out long enough to make repairs and leave orbit?
Teleoperated Robots...
Screw that. I'm in Jovian orbit for the view on my 22nd honeymoon. The septuple-redundant AI systems are taking care of all that crap.


Re Focus Fusion -- Lerner's good at fundraising. I don't believe electrode erosion is going to allow sufficient pulses to get anything like a reactor going.