The reactivity gain in Pu239 is more than offset with and increase in the neutron poisons xenon-135 (microscopic cross-section σ = 2,000,000 b (barns)) and samarium-149 (σ = 74,500 b).
This buildup in neutron poisons is why there is so much Pu239 in nuclear waste; One of the big issues with fission reactors. On Mon, Mar 3, 2014 at 12:09 PM, Bob Cook <frobertc...@hotmail.com> wrote: > Axil-- > > I agree with what you say except I do not understand you comment about > heating up U-238. U-238 in a reactor transmutes to Pu-239, however, the > Pu-239 has a thermal fission cross section just as you say and as it grows > in abundance in a reactor becomes a significant part of the overall energy > production. Since the physics (absorption and production of neutrons) in a > Pu reactor is different than a U reactor, the design for reactivity control > is different. > > Also as you note the delayed neutrons are important in the reactor > Dynamics and Control design as regards response times. They must be > considered in the calculation of neutron produced by the reactor and the > total inventory at any given time. > > Bob > > > > ----- Original Message ----- > > *From:* Axil Axil <janap...@gmail.com> > *To:* vortex-l <vortex-l@eskimo.com> > *Sent:* Monday, March 03, 2014 8:46 AM > *Subject:* Re: [Vo]:"Christopher H. Cooper" > > 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 >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
