jordan@greipa.UUCP (Jordan K. Hubbard) (07/17/85)
In my previous article on fusion, I state that fusion had
been achieved at AMES with the shiva laser. Sorry LLL, I meant
you. My apologies to the people at Livermore..
BTW, isn't the new NOVA laser supposed to 'break even' in energy
input/output? Does anyone know anything about this?
I know the original shiva used a lithium 'waterfall' to capture some
of the energy (presumably to be thrown away), what scheme
have they devised this time?
--
Jordan K. Hubbard
@ Genstar Rental Electronics.
Palo Alto, CA.
{pesnta, decwrl, dual, pyramid}!greipa!jordan
"ack pfffft. gag. retch. barf.. ack"
- Bill again.grl@charm.UUCP (George Lake) (07/19/85)
A note on "breaking even":
When I last looked, this meant that the plasma heated itself as
much as it was heated. It ignores the inefficiencies of plasma
heating (I know, space heaters are 100% efficient, but they don't
heat plasmas) and the ineff. of converting heat to electrical power.
No one has ever collected energy from these fusion devices!
By way of prediction: Fusion energy will not supply power to
the grid in this century
Brief reason: the extrapolated plans for power plants calls for
them to be far too large-- e.g. one plant to supply all
of New York City is on the small side. A plant of this
size isn't feasible to be plugged into the grid. It
is distabilizing to power generation (what do you do when
it goes down-- cut over to other plants? Then why build it)
It is also not acceptable from a defense standpoint.brooks@lll-crg.ARPA (Eugene D. Brooks III) (07/20/85)
> BTW, isn't the new NOVA laser supposed to 'break even' in energy > input/output? Does anyone know anything about this? It depends on how you count the beans, but then who believes bean counters anyway.
gdh@dcl-cs.UUCP (Gareth Husk) (07/22/85)
In article <694@charm.UUCP> grl@charm.UUCP (George Lake) writes: >A note on "breaking even": > >When I last looked, this meant that the plasma heated itself as >much as it was heated. It ignores the inefficiencies of plasma >heating (I know, space heaters are 100% efficient, but they don't ^^^^^^^^^^^^^^^ >heat plasmas) and the ineff. of converting heat to electrical power. Ahem , forgive me if i'm wrong but if I remember my thermodynamics correctly ( and I will undoubtedly be corrected if wrong ) surely a little thing called entropy prevents ANY transfer of energy from being 100% efficient. I haven't got my notes but I think it's the 2nd Law of Thermodynamics ( again correct me if I'm wrong ) states that entropy always increases. Oh well let's see if I've blown what little chance I ever had of studying Physics again. -- " I'm at the bottom of a deep , dark , hole looking up .... what does this remind me of ? ... oh yes ... LIFE . " Marvin (Your plastic pal who is fun to be with) the paranoid android. UUCP: ...!seismo!mcvax!ukc!dcl-cs!gdh DARPA: gdh%lancs.comp@ucl-cs | Post: University of Lancaster, JANET: gdh@uk.ac.lancs.comp | Department of Computing, Phone: +44 524 65201 ext 4146 | Bailrigg, Lancaster, LA1 4YR, UK.
morse@leadsv.UUCP (Terry Morse) (07/25/85)
> >... (I know, space heaters are 100% efficient, but they don't > ^^^^^^^^^^^^^^^ > > Ahem , forgive me if i'm wrong but if I remember my thermodynamics > correctly ( and I will undoubtedly be corrected if wrong ) surely > a little thing called entropy prevents ANY transfer of energy from > being 100% efficient. > I haven't got my notes but I think it's the 2nd Law of > Thermodynamics ( again correct me if I'm wrong ) states that entropy > always increases. > I just love it when someone brings up a thermo question in net.physics. The answer to the above question is that energy transfer can be 100% efficient, as are resistive heaters. The second law only specifies that the total entropy *after* the energy transfer will be greater. This is the same as saying the energy transfer is a one way process (irreversible). 100 Joules of electrical power can generate 100 Joules of thermal energy, but 100 Joules of thermal energy can never generate 100 Joules of electrical energy. After having said that, space heaters are a stupid waste of electricity. There are so many cheaper ways of generating heat. -- Terry Morse (408)743-1487 { seismo!nsc!cae780 } | { sun!sunncal } leadsv!morse
pmk@prometheus.UUCP (Paul M Koloc) (07/30/85)
> A note on "breaking even": > When I last looked, this meant that the plasma heated itself as > much as it was heated. It ignores the inefficiencies of plasma > heating (I know, space heaters are 100% efficient, but they don't > heat plasmas) and the ineff. of converting heat to electrical power. > George R. Lake There are two "break evens" scientific and commercial. Since, all of the DOE funded projects will never work "commercially" primarily for engineering reasons, they only talk about "scientific breakeven". The reason for this is that DOE only funds concepts for which there is a "plasma physics basis". It turns out that plasma physics is being discovered largely due to the work in fusion. The DOE can only fund projects that have been invented and tested else- where, unless they are so damn complicated, i. e. "Elmo bumpy torus", that the theorist have enough loop holes to think it might work. The two biggest and oldest devices are the tokamak and mirror (both from mother Russia) and neither has the slightest hope of being commercialized. And burn radiactive Tritium-Deuterium which then generates copious amounts of neutrons??? Dumb! The "National Fusion Program" is a joke, it can't stop funding obsolete concepts. Why?: because it doesn't apply engineering criteria to determine if it can be commercialized after a reasonable period of physics investigation (5-10 years). Think of it simply "does it cost to much to build and maintain." On the other hand it can't start new projects, either. > No one has ever collected energy from these fusion devices! > By way of prediction: Fusion energy will not supply power to > the grid in this century If DOD gets interested "they need high power density not so much energy" then your predictions will not hold. Even the Sphermoak could produce very useful pulsed power for defense applications and the PLASMAKtm technology appears to be able to generate fusion with the proficiency and application found in science fiction movies. For engineering reasons, PLASMAKtm commercial fusion "breakeven" could be demonstrated within three years. Success would be guaranteed within one year if the special magnetoplasmoid can be formed. Continuouly forming and burning the fusion core of these plasmoids at sixty hertz, would generate 1 mega kilowatt electric, and the volume of each compressed plasmoid would be only 100 cubic centimeters. A good fuel would be Hydrogen Boron-isotope eleven. It would not have the difficult plant size problems or down times extrapolated for the DOE devices. And, as a final note, Bell Telephone Labs, Murray Hill NJ, Akira Hasegawa has invented a super compressed PLASMAKtm generated with a laser or particle beam. This work may be funded here only because the inertial confinment division is under the gun and can't justify its existance with the crappy prospects of approaches such a "NOVA". This work will more likely be carried out by the Japanese at Osaka. M. Mimura is also involved in more conventional PLASMAKtm research. PLASMAKtm is a trademark of Prometheus II, Ltd. - - NOTE: MAIL PATH MAY DIFFER FROM HEADER - - +-------------------------------------------------------+--------+ | Paul M. Koloc, President: (301) 445-1075 | FUSION | | Prometheus II Ltd., College Park, MD 20740-0222 | this | | pmk@prometheus.UUCP; ..seismo!prometheus!pmk.UUCP | decade | +-------------------------------------------------------+--------+
grl@charm.UUCP (George Lake) (08/01/85)
I had a passing remark that space heaters are 100% efficient that was objected to on the basis of the second law of thermodynamics. A space heater takes electricity and converts it to heat-- a highly entropic process and it is 100% efficient. The second law tells you that you can't go the other way with 100% eff. BTW, heat pumps have an efficiency greater than 100%. They are air conditioners run backwards. They generate heat on their own and draw some from the ground. They still obey the second law. Sorry to take up space responding to a silly attempt by someone to be clever.
mcgeer%ucbkim%Berkeley)@sri-unix.ARPA (08/06/85)
From: mcgeer%ucbkim@Berkeley (Rick McGeer (on an aaa-60-s)) >BTW, heat pumps have an efficiency greater than 100%. They >are air conditioners run backwards. They generate heat on their >own and draw some from the ground. They still obey the >second law. I take it that efficiency, for purposes of this discussion, is joules of heat delivered/joules consumed in operation. What is the typical efficiency of a commercial heat pump? Rick.
morse@leadsv.UUCP (Terry Morse) (08/08/85)
In article <467@sri-arpa.ARPA>, mcgeer%ucbkim%Berkeley)@sri-unix.ARPA writes: > > I take it that efficiency, for purposes of this discussion, is > joules of heat delivered/joules consumed in operation. What is the typical > efficiency of a commercial heat pump? > > Rick. When talking about heat pumps, the term for "efficiency" is called coefficient of performance, which is defined by joules out over joules in. It is mostly driven by the amount of temperature rise required. It can be as low as 1.5 or as high as 4 (some solar assisted water source heat pumps can attain a COP of 4). Unless natural gas is very expensive or unattainable, even a heat pump costs more than a gas furnace to operate. -- Terry Morse (408)743-1487 { seismo!nsc!cae780 } | { sun!sunncal } !leadsv!morse