The delayed neutrons are the neutrons that come from the radioactive decay of activated fission products. They slow down fission so that heat can get to the U238. Without delayed neutrons, the fission reaction would go super-critical in nanoseconds which would not allow the U238 to heat up.
The fission cross section of U233, Pu239, and U235 all goes up as neutrons slow down. That is why Pu239, is used in fast neutron reactors; because it produces more neutrons per fission than uranium. Fast neutrons produce less fissions that slow one do. On Mon, Mar 3, 2014 at 11:23 AM, Bob Cook <frobertc...@hotmail.com> wrote: > Axil-- > > I may be wrong but it was always my understanding that the fissile isotope > is U-235 and that the energy of the neutrons is important. The reactivity > decreases as the temperature increases because the fission cross section is > lower and reactivity is reduced with the hotter neutron. It may actually > be a Doppler broadening of the of the neutron wave function that changes > the effective fission cross section of U-235. > > Bob > > ----- Original Message ----- > *From:* Axil Axil <janap...@gmail.com> > *To:* vortex-l <vortex-l@eskimo.com> > *Sent:* Monday, March 03, 2014 7:52 AM > *Subject:* Re: [Vo]:"Christopher H. Cooper" > > > > > On Mon, Mar 3, 2014 at 10:06 AM, Bob Cook <frobertc...@hotmail.com> wrote: > >> Axil-- >> >> Fission reactors with water cooling generally have a negative temperature >> feedback and are much safer than metal coolant reactors with positive >> temperature feedback. However, metal cooled reactors have been designed >> and worked ok. With good design even a positive temperature feedback may >> work. >> > > In a uranium reactor, U238 provides the negative temperature control > through Doppler broadening. > > > http://www.safetyinengineering.com/FileUploads/Nuclear%20reactor%20stability%20and%20controllability_1314016641_2.pdf > > Light water absorbs more neutrons then heavy water and sodium hardly > absorbs any neutrons (fast ones) at all. > > Designing a fission reactor requires a lot of experience and education. > > Positive coefficient of reactivity can never be positive. That is inviting > a possibility of super criticality. A reactor that can go super critical > cannot be licensed. > > In a QM system things happen so fast it would be harder to control than >> in a fission reactor. The key for control may be to limit the size of the >> QM system that reacts at any time, or increase the response time of >> the initiator--may the on-off pulse of the magnetic field in the case of >> the Pd and Ni systems. >> > > The DGT LENR reactor is only supercritical when the spark is arcing. > But when the spark is off, that reactor returns to sub criticality. > > DGT tossed Rossi out of their deal because his reactor can go super > critical. DGT designed their home grown reactor to be inherently safe > through sub criticality just like all fission reactors. > > >> >> Bob >> >> ----- Original Message ----- >> *From:* Axil Axil <janap...@gmail.com> >> *To:* vortex-l <vortex-l@eskimo.com> >> *Sent:* Sunday, March 02, 2014 12:04 PM >> *Subject:* Re: [Vo]:"Christopher H. Cooper" >> >> What is the course of an open ender positive feedback loop without limit. >> An eventual explosion. Nothing lasts forever in a positive feedback loop. >> There is always a limit to everything. >> >> >> On Sun, Mar 2, 2014 at 3:00 PM, David Roberson <dlrober...@aol.com>wrote: >> >>> Interesting. But how does the net field become large unless some >>> mechanism coordinates the destruction of the balls? Many random direction >>> vectors yields near zero sums. >>> >>> Dave >>> >>> >>> >>> -----Original Message----- >>> From: Axil Axil <janap...@gmail.com> >>> To: vortex-l <vortex-l@eskimo.com> >>> Sent: Sun, Mar 2, 2014 2:55 pm >>> Subject: Re: [Vo]:"Christopher H. Cooper" >>> >>> Yes, there is a load of fun in this sort of speculation. One >>> possibility is that micro sized magnetic balls as described by DGT that >>> start small and grow to huge power until they explode could produce a >>> varying magnetic field that would induce a current through changing >>> magnetic flux.. >>> >>> >>> On Sun, Mar 2, 2014 at 2:46 PM, David Roberson <dlrober...@aol.com>wrote: >>> >>>> That brings back fond memories. He does say e.m.f. which makes me >>>> wonder how he performed that measurement. I would anticipate that he must >>>> use at least two probes to come to that conclusion and his active material >>>> hopefully does not short out the voltage. >>>> >>>> Another possibility is that he measured a large magnetic field which he >>>> assumes must be as a result of DC current flowing. Since DC current or AC >>>> for that matter requires a loop voltage in order to flow, it makes sense to >>>> believe that an e.m.f. is present. Actually, an e.m.f. should be present >>>> in that case and what Rossi states below about an expert observing it falls >>>> into line. >>>> >>>> I find myself wondering if there are other good ways to achieve very >>>> high strength magnetic fields without currents flowing. Permanent magnets >>>> offer a clue. >>>> >>>> I am guessing here and attempting to decode Rossi speak at the same >>>> time. That has its hazards! :-) >>>> >>>> Dave >>>> >>>> >>>> >>>> -----Original Message----- >>>> From: Axil Axil <janap...@gmail.com> >>>> To: vortex-l <vortex-l@eskimo.com> >>>> Sent: Sun, Mar 2, 2014 2:25 pm >>>> Subject: Re: [Vo]:"Christopher H. Cooper" >>>> >>>> Andrea Rossi >>>> > December 30th, 2012 at 3:01 PM >>>> > >>>> http://www.journal-of-nuclear-physics.com/?p=771&cpage=4#comment-514345 >>>> >>>> Dear Bernie Koppenhofer: >>>> You are touching a very important point: during these very days, and >>>> also >>>> during the more recent tests, we are working on this issue. I think >>>> we will >>>> be able to produce directly e.m.f. , but much work has to be done. >>>> Actually, we already produced direct e.m.f. with the reactors at high >>>> temperature, and we measured it with the very precise measurement >>>> instrumentation introduced by the third party expert, but we are not >>>> ready >>>> for an industrial production, while we are at a high level of >>>> industrialization for the production of heat and, at this point , >>>> also of >>>> high temperature steam, which is the gate to the Carnot Cycle. Thank >>>> you >>>> for your good comment. >>>> Warm Regards, >>>> A.R. >>>> >>>> >>>> >>>> On Sun, Mar 2, 2014 at 2:04 PM, Axil Axil <janap...@gmail.com> wrote: >>>> >>>>> I believe that heat is not the only product of the LENR reaction. It >>>>> may not even the most important sink for LENR power generation. I believe >>>>> that electron production is a major magnification of over unity power >>>>> generation. >>>>> Rossi indicated that there was an unknown source of current production >>>>> in his reactor and he was looking into how this could happen. >>>>> I know that the PAPP engine produced current out of whole cloth. The >>>>> design of the engine depended on it. >>>>> Here is my take on where these electrons are coming from. When the >>>>> magnetic field strength gets strong enough, mesons are condensed out of >>>>> the >>>>> vacuum. The final decay products of mesons are electrons. >>>>> >>>>> >>>>> >>>>> On Sun, Mar 2, 2014 at 1:34 PM, David Roberson <dlrober...@aol.com>wrote: >>>>> >>>>>> I also find it amazing that DGT seems to overlook the implications >>>>>> of their discovery. It reminds me of not seeing the forest through the >>>>>> trees. >>>>>> >>>>>> Since Rossi made an earlier claim that he might be able to generate >>>>>> electricity directly by some obscure discovery, I suspect that he >>>>>> realized >>>>>> the importance of the large magnetic fields residing within his device. >>>>>> So >>>>>> far he has kept this type of information private, carefully leaking out >>>>>> the >>>>>> news of some non specific discovery. Rossi knows when to release >>>>>> findings >>>>>> that might assist competitors. >>>>>> >>>>>> Dave >>>>>> >>>>>> >>>>>> >>>>>> -----Original Message----- >>>>>> From: Axil Axil <janap...@gmail.com> >>>>>> To: vortex-l <vortex-l@eskimo.com> >>>>>> Sent: Sun, Mar 2, 2014 1:23 pm >>>>>> Subject: Re: [Vo]:"Christopher H. Cooper" >>>>>> >>>>>> Like you, any one of us can only do so much of what is required. >>>>>> To come up with an all inclusive theory, we must trust the word and the >>>>>> work done by others. >>>>>> >>>>>> I must admit that I trust DGT. So far, their experimental observation >>>>>> about magnetic field strength has no impact on the theory (HEMI) that >>>>>> they >>>>>> put forward. >>>>>> >>>>>> They have no theroritical based interest in misleading us to advance >>>>>> their theory base on Dr. Kims work. >>>>>> >>>>>> Like us, DGT is simply amazed at the magnetic nature of their >>>>>> experimental find but have not connected it to HEMI in any way. This is >>>>>> hard to understand. >>>>>> >>>>>> On the part of DGT, there is no self interest in tossing an almost >>>>>> unbelievable finding into their finding and in fact this finding >>>>>> undercuts >>>>>> HEMI. >>>>>> >>>>>> In fact such a finding is a major distraction. They really need to do >>>>>> a major rethink of their experimental position on HEMI and BEC as per Dr. >>>>>> Kim. >>>>>> >>>>>> >>>>>> On Sun, Mar 2, 2014 at 1:03 PM, Edmund Storms >>>>>> <stor...@ix.netcom.com>wrote: >>>>>> >>>>>>> >>>>>>> On Mar 2, 2014, at 10:47 AM, Axil Axil wrote: >>>>>>> >>>>>>> > These Nanoplasmonic experiments with uranium can be done >>>>>>> inexpensively, why can't Ed replicate these experiments? >>>>>>> >>>>>>> Because I have only two hands and no financial support. If you want >>>>>>> this replicated, I suggest you hire someone to do this. >>>>>>> >>>>>>> Ed Storms >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
