Mhmm, riiight, because very heathy people never EVER get cancer! Don't liet logic or reason sway your righteous conviction! Cancer is always caused by eeeevil environmental toxins!
really. wow. when do you pick up your nobel prize for discovering the spontaneous alchemical transformation of elements!? If you spent even one minute researching what you thought you were speaking authoritatively on, you would know that Phosgene is COCl2 and teflon (PTFE) consists solely of carbon and fluorine atoms. So unless you are magically summoning chlorine from the great beyond what you say is impossible. but no, you decided not to take the extra 2 seconds to double check your facts and instead posted yet more emptyheaded bullshit to a story already rife with said matter. oh and one more thing, you're an idiot.
"They claim that the pants contain teflon, which is in a family of chemicals that can be absorbed through the skin. It is known that this same family of chemicals accumulates in the body, that most Americans have some level of this in their bodies, and that there is research to show that it damages immune systems in other animals."
Really? Because to be perfectly honest I think you're talking completely out your ass as an uninformed and fearmongering fool. It is obvious from your post that you are not a chemist and in fact have not even the most rudimentary understanding of chemistry. So what eeeevil "family of chemicals" is this you speak of? Polymers? Wow I guess I better stop drinking out of plastic bottles then. In fact I better go seal myself off from the world now since my body contains POLYsaccharide molecules like starch. Is it fluorocarbons that are so deadly "to our immune systems"? Huh, well I guess we can't use perflubron to save premature infants from suffocation. Sigh, oh well. Maybe its halogenated hydrocarbons in general that you deem the bane of humanity. Get rid of electronic fire extinguishing materials and any number of other halogenated polymers we use in every day existence. yeah. three cheers for mindless anti-intellectual pseudoscientific promulgations.
nothing special. the plate slams into a target and launches a shockwave into the material of interest. the KE is dissipated as heat and light within a short time.
It wasn't the magnetic field that induced a current in and heated the Al. It was the RF pulse used to align the proton spin in the patient. The Al pin acted like an antenna and absorbed the RF from the MRI which then heated ohmically.....Not that it matters much to the person with a partly cooked arm...:-(
Oh! oops. They really did use the magnetic field of Z to directly accelerate the plate! Apparently the way they circumvented the problem of vaporizing the plate with a huge current pulse is by staggering Z's laser triggered spark gaps to elongate the current pulse from tens to hundreds of ns. Very neat trick.
This is so stupid. I fully concur with with nrlightfoot. There is NO WAY any scientist working on something like this would ever, EVER say this even has anything remotely to do with railguns. Firstly, if you used it as a weapon, the projectile would vaporize as soon as it encountered atmosphere!! Second, it is not at all capable of accelerating large (Kg scale) projectiles relevant to weaponry applications. This technique is only used for equation of state measurements and shockwave/fluid dynamics interaction experiments. Furthermore, the achieveable pressure regimes attainable by this method are not really groundbreaking. High power lasers for fusion research are also used to do the exact same thing except they accelerate the pusher plate not by magnetic induction but by initiating fast foam layer vaporization. The NOVA laser at LLNL attained about the same megabar pressures back in the 90's, though its nice to see there is another method now available to do this (that is, besides detonating nuclear weapons- the only other method I'm aware of). Now that I think of it, the reporting on this achievement is universally bad (no surprse there really) and I can't really tell how the pusher was accelerated in this experiment. It COULD be that since it was a metal plate they actually did use the magnetic field of the Z machine to directly accelerate it however, it was so small and thin I very strongly suspect that if in fact this method was used the current induced in the metal foil would've been so immense that it would've instantly vaporized. No, I rather think what they did was to use the Z-pinch of the machine to heat a plasma inside a hohlraum to very high temperature so that it emits a giant pulse of X-rays (this is the usual modus operandi of the Z-machine) which was then used to vaporize a metal or foam pusher which then accelerated the aluminum plate....
Sweetie we already talked about this,.... remember? You have to take the little pink pill eeeevery day or doctor will be upset with you next time we visit.....mmmmk hon?
Weird! I'm reading that book right now!:) If you want more info on this stuff I suggest checking out the online version of the Lab for Laser Energetics Review publication. We have the past 10 years of it up for free viewing. Its pretty dense stuff (heh) but if you can handle dark sun I don't think you'll have a problem.
I assume you mean "holding them back from achieving ignition". Two things moslty, the ability to deliver a large enough amount of energy to the target in a short enough period of time and the ability to overcome hydrodynamic instabilities like Raliegh-Taylor instability. These problems are harder to solve than most people thought back in the 70's.
Cool indeed. I can't help but wonder what Carl Sagan would think of this if he were around to see it happen....Sadly we have only his past eloquence to ponder and we are now left to our own devices in order to comprehend the magnitude of this event. We are now an interstellar species. The first ever on Earth and the only one we know of. There is no turning back now. Though perhaps it is time for Voyager to turn back, one last time to send us an image of ourselves from the incomprehensible beyond. Our planet will of course not be visible anymore, and our sun will probably appear as a mere unremarkable dot among a thousand others.
"I was once on a [Can't tell you] site debugging their Token Ring network (It turned out that EMPs from their various 'experiments' were getting into the optical fibre via the transceivers on the NICs, but that's another story!)."
My guess: you were at the CCLRC's CLF Vulcan laser.... am I right?:)
Actually timing, beamshape, and power issues are all the easy bits to solve. Repeatability is very high from shot to shot on other big fusion lasers. If you want to know more about the history of lasers used for high energy density experiments go to the LLNL library do and search on "shiva" "argus" or "nova" lasers to find papers published on the experiments of these first systems. Most of the timing/power issues were solved over 20 years ago.
oops! I misspoke! Q=1 actually referrs to the point of breakeven and ignition will occur somewhat above this point due to energy losses of the plasma....NIF will actually achieve high gain with a Q of >~50!!
Yes we very often see the CEA guys poking around here. Probably doing scaled implosions to verify LMJ's ignition capability... Do you know if the CEA is planning any large chirped pulse stuff?
I don't think I've ever friended someone that fast!:) One question though, how do they grow a flouroapatite crystal like this?! Incidentally, if you don't mind my asking, where do you work?
There is one method (that I know of) which is capable of direct conversion of nearly all the energy of the fusion plasma into electricity. It is not possible in inertial confinement laser fusion though. It is the P + B-11 reaction. This involves the fusion of protons (normal hydrogen) and Boron 11 in a magnetically confined fusion reactor called a colliding beam fusion reactor. There is nearly zero neutronicity in this reaction (.001) and the product is 3 He atoms. In this scheme there is sort of a scrape off layer at an end of the reactor where the product He ions are directed into a magnetron cavity where they are decelerated and produce microwaves, the microwaves are collected with an antenna and rectified to DC power. Also they use something called an "inverse cyclotron" to do essentially the same thing at lower frequencies. It is estimated that a 90% fusion power to electricity output could be achieved using this scheme. Cool eh? What's the catch you ask? Well, its generally thought to be impossible (or VERY nearly so). This is because P-B11 fusion does not take place at the tepid 100 Mega Kelvins of DT fusion but instead at a blistering 1.4 BILLION K (123 KeV)!! This obviously complicates things immensely.
"Each laser charges up to one terrajoule of energy, then outputs one terrawatt for one second."
Juuust slightly off...by a factor of a billion or so!:-) Actually the NIF will fire each of its 192 beams simultaneously with an energy of ~10kJ for a duration of 2-3 nanoseconds for a total of nearly 2 MJ on the target. The overall power of the laser will be somewhere near 500 Terawatts (trillion watts) and despite what the AP article says, that will never secure its stature as being the "worlds most powerful", that title is currently held by the Rutherford Appleton laboratory's Vulcan Petawatt laser, capable of achieving nearly 1 thousand trillion watts of power. The OMEGA EP laser, to be completed in 1-2 years will achieve over 2 Petawatts of power. These lasers only deliver few kJ total energy though.
Well, the easiest fusion reaction to do is the Deuterium Tritium reaction (DT). That is, it is the reaction which requires the "lowest" temperature to ignite. Thing is, most of the energy released in this reaction is in the form of hot neutrons. The percentage of the fustion energy released in the reaction as neutrons is called the reaction's "neutronicity" and is something like 80% for DT. This really sucks because neutrons, as you may be aware, are absorbed into the nuclei of the surrounding structure material, transmuting its constituent atoms into radioactive isotopes (albeit with relatively short half-lives). Soooo, the best idea around these days is to create a vacuum target chamber with...wait for it.... undulating "waterfalls" of hot liquid lithium or "filbe" (Lithium Fluoride Beryllium Fluoride mix). The Li absorbs the neutrons and is heated in the process, the heat is then sent to boil water/run turbines, and the usual. There is a bonus in this scheme though, the Li after absorbing a neutron is transmuted into more Tritium! More Fuel! This is called the HYLIFE II reactor design.
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Mhmm, riiight, because very heathy people never EVER get cancer! Don't liet logic or reason sway your righteous conviction! Cancer is always caused by eeeevil environmental toxins!
....wtf?
"Eric, if you're in here, we're all going to Marty's after the movie"
I know! And the rest of the posters are too stupid to know the difference between the words to and too!
really. wow. when do you pick up your nobel prize for discovering the spontaneous alchemical transformation of elements!? If you spent even one minute researching what you thought you were speaking authoritatively on, you would know that Phosgene is COCl2 and teflon (PTFE) consists solely of carbon and fluorine atoms. So unless you are magically summoning chlorine from the great beyond what you say is impossible. but no, you decided not to take the extra 2 seconds to double check your facts and instead posted yet more emptyheaded bullshit to a story already rife with said matter. oh and one more thing, you're an idiot.
"They claim that the pants contain teflon, which is in a family of chemicals that can be absorbed through the skin. It is known that this same family of chemicals accumulates in the body, that most Americans have some level of this in their bodies, and that there is research to show that it damages immune systems in other animals."
Really? Because to be perfectly honest I think you're talking completely out your ass as an uninformed and fearmongering fool. It is obvious from your post that you are not a chemist and in fact have not even the most rudimentary understanding of chemistry. So what eeeevil "family of chemicals" is this you speak of? Polymers? Wow I guess I better stop drinking out of plastic bottles then. In fact I better go seal myself off from the world now since my body contains POLYsaccharide molecules like starch. Is it fluorocarbons that are so deadly "to our immune systems"? Huh, well I guess we can't use perflubron to save premature infants from suffocation. Sigh, oh well. Maybe its halogenated hydrocarbons in general that you deem the bane of humanity. Get rid of electronic fire extinguishing materials and any number of other halogenated polymers we use in every day existence. yeah. three cheers for mindless anti-intellectual pseudoscientific promulgations.
nothing special. the plate slams into a target and launches a shockwave into the material of interest. the KE is dissipated as heat and light within a short time.
hello brian from wikipedia! Do you know if they used beamlet to backlight shock propagation? :o) just curious!
It wasn't the magnetic field that induced a current in and heated the Al. It was the RF pulse used to align the proton spin in the patient. The Al pin acted like an antenna and absorbed the RF from the MRI which then heated ohmically.....Not that it matters much to the person with a partly cooked arm... :-(
Oh! oops. They really did use the magnetic field of Z to directly accelerate the plate! Apparently the way they circumvented the problem of vaporizing the plate with a huge current pulse is by staggering Z's laser triggered spark gaps to elongate the current pulse from tens to hundreds of ns. Very neat trick.
This is so stupid. I fully concur with with nrlightfoot. There is NO WAY any scientist working on something like this would ever, EVER say this even has anything remotely to do with railguns. Firstly, if you used it as a weapon, the projectile would vaporize as soon as it encountered atmosphere!! Second, it is not at all capable of accelerating large (Kg scale) projectiles relevant to weaponry applications. This technique is only used for equation of state measurements and shockwave/fluid dynamics interaction experiments. Furthermore, the achieveable pressure regimes attainable by this method are not really groundbreaking. High power lasers for fusion research are also used to do the exact same thing except they accelerate the pusher plate not by magnetic induction but by initiating fast foam layer vaporization. The NOVA laser at LLNL attained about the same megabar pressures back in the 90's, though its nice to see there is another method now available to do this (that is, besides detonating nuclear weapons- the only other method I'm aware of). Now that I think of it, the reporting on this achievement is universally bad (no surprse there really) and I can't really tell how the pusher was accelerated in this experiment. It COULD be that since it was a metal plate they actually did use the magnetic field of the Z machine to directly accelerate it however, it was so small and thin I very strongly suspect that if in fact this method was used the current induced in the metal foil would've been so immense that it would've instantly vaporized. No, I rather think what they did was to use the Z-pinch of the machine to heat a plasma inside a hohlraum to very high temperature so that it emits a giant pulse of X-rays (this is the usual modus operandi of the Z-machine) which was then used to vaporize a metal or foam pusher which then accelerated the aluminum plate....
pffft....puhlease... faster still... C6H6CH2CH(NHCH3)CH3
Hopefully this venture will fare better than the Summer Of George.
Sweetie we already talked about this,.... remember? You have to take the little pink pill eeeevery day or doctor will be upset with you next time we visit.....mmmmk hon?
Weird! I'm reading that book right now! :) If you want more info on this stuff I suggest checking out the online version of the Lab for Laser Energetics Review publication. We have the past 10 years of it up for free viewing. Its pretty dense stuff (heh) but if you can handle dark sun I don't think you'll have a problem.
I assume you mean "holding them back from achieving ignition". Two things moslty, the ability to deliver a large enough amount of energy to the target in a short enough period of time and the ability to overcome hydrodynamic instabilities like Raliegh-Taylor instability. These problems are harder to solve than most people thought back in the 70's.
Cool indeed. I can't help but wonder what Carl Sagan would think of this if he were around to see it happen....Sadly we have only his past eloquence to ponder and we are now left to our own devices in order to comprehend the magnitude of this event. We are now an interstellar species. The first ever on Earth and the only one we know of. There is no turning back now. Though perhaps it is time for Voyager to turn back, one last time to send us an image of ourselves from the incomprehensible beyond. Our planet will of course not be visible anymore, and our sun will probably appear as a mere unremarkable dot among a thousand others.
"I was once on a [Can't tell you] site debugging their Token Ring network (It turned out that EMPs from their various 'experiments' were getting into the optical fibre via the transceivers on the NICs, but that's another story!)."
:)
My guess: you were at the CCLRC's CLF Vulcan laser.... am I right?
Actually timing, beamshape, and power issues are all the easy bits to solve. Repeatability is very high from shot to shot on other big fusion lasers. If you want to know more about the history of lasers used for high energy density experiments go to the LLNL library do and search on "shiva" "argus" or "nova" lasers to find papers published on the experiments of these first systems. Most of the timing/power issues were solved over 20 years ago.
oops! I misspoke! Q=1 actually referrs to the point of breakeven and ignition will occur somewhat above this point due to energy losses of the plasma....NIF will actually achieve high gain with a Q of >~50!!
Yes we very often see the CEA guys poking around here. Probably doing scaled implosions to verify LMJ's ignition capability... Do you know if the CEA is planning any large chirped pulse stuff?
How far along IS the LMJ by the way....?
I don't think I've ever friended someone that fast! :) One question though, how do they grow a flouroapatite crystal like this?! Incidentally, if you don't mind my asking, where do you work?
There is one method (that I know of) which is capable of direct conversion of nearly all the energy of the fusion plasma into electricity. It is not possible in inertial confinement laser fusion though. It is the P + B-11 reaction. This involves the fusion of protons (normal hydrogen) and Boron 11 in a magnetically confined fusion reactor called a colliding beam fusion reactor. There is nearly zero neutronicity in this reaction (.001) and the product is 3 He atoms. In this scheme there is sort of a scrape off layer at an end of the reactor where the product He ions are directed into a magnetron cavity where they are decelerated and produce microwaves, the microwaves are collected with an antenna and rectified to DC power. Also they use something called an "inverse cyclotron" to do essentially the same thing at lower frequencies. It is estimated that a 90% fusion power to electricity output could be achieved using this scheme. Cool eh? What's the catch you ask? Well, its generally thought to be impossible (or VERY nearly so). This is because P-B11 fusion does not take place at the tepid 100 Mega Kelvins of DT fusion but instead at a blistering 1.4 BILLION K (123 KeV)!! This obviously complicates things immensely.
"Each laser charges up to one terrajoule of energy, then outputs one terrawatt for one second."
:-) Actually the NIF will fire each of its 192 beams simultaneously with an energy of ~10kJ for a duration of 2-3 nanoseconds for a total of nearly 2 MJ on the target. The overall power of the laser will be somewhere near 500 Terawatts (trillion watts) and despite what the AP article says, that will never secure its stature as being the "worlds most powerful", that title is currently held by the Rutherford Appleton laboratory's Vulcan Petawatt laser, capable of achieving nearly 1 thousand trillion watts of power. The OMEGA EP laser, to be completed in 1-2 years will achieve over 2 Petawatts of power. These lasers only deliver few kJ total energy though.
Juuust slightly off...by a factor of a billion or so!
Well, the easiest fusion reaction to do is the Deuterium Tritium reaction (DT). That is, it is the reaction which requires the "lowest" temperature to ignite. Thing is, most of the energy released in this reaction is in the form of hot neutrons. The percentage of the fustion energy released in the reaction as neutrons is called the reaction's "neutronicity" and is something like 80% for DT. This really sucks because neutrons, as you may be aware, are absorbed into the nuclei of the surrounding structure material, transmuting its constituent atoms into radioactive isotopes (albeit with relatively short half-lives). Soooo, the best idea around these days is to create a vacuum target chamber with ...wait for it.... undulating "waterfalls" of hot liquid lithium or "filbe" (Lithium Fluoride Beryllium Fluoride mix). The Li absorbs the neutrons and is heated in the process, the heat is then sent to boil water/run turbines, and the usual. There is a bonus in this scheme though, the Li after absorbing a neutron is transmuted into more Tritium! More Fuel! This is called the HYLIFE II reactor design.