Pokhran II not fully successful: Scientist

[RPK]

Pokhran – II tests were fully successful; given India capability to build nuclear deterrence: Dr. Kakodkar and Dr. Chidambaram

PIB Press Release


The Union government has reiterated that the Pokhran-II nuclear tests in May’98 were fully successful. Addressing a press conference in Mumbai this morning, Dr. Anil Kakodkar, Chairman, Atomic Energy Commission (AEC) and Dr. R. Chidambaram, Principal Scientific Advisor and former Chairman, Atomic Energy Commission said, “The Pokhran-II tests had achieved their scientific objectives and had given India the capability to build fission and thermonuclear fusion weapons from low yields up to around 200 kilo tonnes (kt).” The statement comes after doubts raised by two scientists Mr. K. Santhanam and Mr. P. K. Iyengar on the success of the Pokhran-II nuclear tests conducted by India on 11th and 13th May, 1998. Mr. Kakodkar also said that on the basis of the capability, India had the ability to meet national security requirements and did not need to conduct more nuclear tests. The AEC Chairman however did not comment on issue of whether India should sign the CTBT Treaty, saying that a number of other factors needed to be taken into consideration for arriving at any decision.

Giving out the scientific details on the success of the May 1998 tests, Dr. Chidambaram, architect of the Pokhran-II tests, said that a number of yield measurement methods based on seismology, radio-chemistry and cavity measurements had confirmed the yield of the tests. He said that reputed US seismologist Professor Jack Evernden, who has professed taking into consideration geological and seismological differences between test sites, had made estimations of the May 1998 tests and they were consistent with India’s results. Dr. Chidambaram said that a number of papers had been written on the results of the tests and they had been peer-reviewed in International Journals of repute. He also said that India now had the computer simulation capability to predict the yields - of nuclear weapons-fission, boosted fission and two-state thermonuclear – of designs related to those tested in May’ 98.

Expressing distress over the objections raised by Shri P. K. Iyengar, the Principal Scientific Advisor said that even P. K. Iyengar agreed with the yield of the tests however the conclusions drawn by him on the efficiency were purely speculative in nature. Dr. Chidambaram wondered how without the knowledge of the design, the nature of fission-fusion break-up and quantity of thermo-nuclear material, Mr. Iyengar could calculate the efficiency the fuel burnt as 10%. He said, “no one outside the design team had the data to calculate fission-fusion yield break-up or any other significant parameter related to fusion burn”. Responding to the doubts raised by Mr. Santhanam, Dr. Chidambaram said that the size of the crater depended on the depth of burial and nature of the rock medium. The Principal Scientific Advisor said that India was the only country, which had given out so much information on the tests and further information could not be revealed because of proliferation-related sensitivities.

A point by point response to the major doubts raised on the Pokhran – II tests as given by Dr. Chidambaram is given below.

Doubt -1

“If one goes by the numbers for the total nuclear yield put out by the Department of Atomic Energy, which I see no reason to dispute, the yield of the thermonuclear device detonated on May 11, 1998, was around 40 kilotons… In my opinion that ratio ( of fission energy to fusion energy) must have been around 1:1… Therefore, by my estimate, the fusion yield could not have been more than 20kt… This suggests that the fusion core burnt only partially, perhaps less than 10 per cent..” (P.K. Iyengar, August 2000, repeated recently )

Response- 1

The important point is that Dr. P.K. Iyengar does not dispute the yield of the thermonuclear test. We do not understand, however, how, without knowledge of the design and, therefore, without knowledge of the fusion-fission breakup ad the quantity of thermonuclear material in the device and its isotopic composition, he has tried to calculate the efficiency of fusion burn.

Doubt- 2

“The fission bomb yield from DRDO’s seismic instrumentation was 25 kiloton…” ( K Santhanam & Ashok Parthasarathi, The Hindu, 17 September, 2009)

Response – 2

The BARC estimate of the yield for the fission device is 15 kiloton ( not 25 kiloton) and for the thermonuclear device 45 kiloton. One of the methods used for the estimation of the device yield was close-in acceleration measurement, for which both DRDO and BARC had set up instrumentation. It soon became apparent that after discussion among the two groups of specialists that the DRDO data had anomalies and had to be rejected and that the BARC data, which had the expected waveforms, would be accepted.

Doubt -3

“..The fission bomb left a crater 25 metres in diameter. If the TN device had really worked with a yield of 50 kiloton, it should have left a crater almost 70 metres in diameter…” ( K. Santhanam & Ashok Parthasarathi, The Hindu, 17 September, 2009)

Response- 3

The surface feature produced at Ground Zero depends on the depth of burial and the rock medium around the shot point and the rock medium between the shot point and the ground. These were all different for the two device tests. The fission device was emplaced in rhyolite medium. The medium for the Pokhran-I test was shale and sandstone. The geology in the Pokhran region is inhomogenous. The propagation of the shock wave is affected by every nterface. 3 – D simulation calculations of the rock mechanical effects done by BARC scientists, after considering all these factors, accounted for the observed effects in the thermonuclear test.

Incidentally, dimensions in rock mechanics scale by the power ( 1/3.4) for underground nuclear explosions- for chemical explosions, they scale by the power ( 1/3) or as cube root; the difference comes from the latent heat absorbed in the former case for vaporizing and melting the rocks around the point of detonation.

Doubt- 4

“Dr. P.K. Iyengar…. Informed me that trace levels of these same ( radio) isotopes ( sodium-22 and manganese-54) were detected in Apsara, a pure fission reactor …..” ( K. Santhanam & Ashok Parthasarathi, The Hindu, 17 September, 2009)

Response – 4

The tail of the fission neutron spectrum extends to beyond the excitation energy of these reactions. But the fusion neutrons are of 14 MeV. That is why isotopes like Mn-54 and Na-22 are found in significant ( not trace) quantities in the rock samples from the thermonuclear device site rock samples. If one sees the gamma-ray spectrum of a typical rock sample of the thermonuclear test site, published in refereed journals by BARC scientists, sharp peaks for these radioisotopes are seen, not just bumps in the background! In the Mn-54/Ce-144 ratios from the samples of the two test sites, reproduced by R. Ramachandran in his Frontline article of 25th September, 2009, this ratio for the thermonuclear test samples is seen as a high multiple of the ratio for the fission test samples”

 

[nitesh]

read full

Why there is no case for further nuclear tests

 

[hit&run]

read full

Why there is no case for further nuclear tests

Yes now there are few reason to test Nukes again,
1.Ever growing Billions dollar Aid to Pakistan (terrorists united again).
2.Anti India UN resolution on NTP.
3.Chines cunning voice on 'world without nuke',
4.OZ (japanese and others very soon) call on AP as chines territory.
5.No guarantee Russia will support India any more in UNO.
6.Narrow chances on UN expension(Indian permanent seat).

Nitesh Sir we don't distrust Indian Scientists/army capabilities. The only language world understand is the language of Power. Its better to be practically correct than politically. India is on its own ................

 

[RPK]

?Santhanam`s views on nuke test are a clincher?

Mumbai: In the midst of the controversy over the success of the 1998 thermonuclear test, nuclear scientist P K Iyengar has said the views of former DRDO scientist K Santhanam on the issue are the "clincher".

There is a "strong reason to believe that the thermonuclear device had not fully burnt and, therefore, further testing was called for," Iyengar, a former Atomic Energy Commission Chairman, said in a statement yesterday.

He rejected the statement attributed to him by government's Principal Scientific Advisor R Chidambaram on the outcome of the 1998 thermonulcear test, saying he was "misquoted" by him on something he had written in 2000.


He said Chidambaram had "tried to imply that I am in agreement with the official number for the yield of the thermonuclear test of 45 kilotons and that I, therefore, also agree that the thermonuclear device was a success.

"This is not correct. What I wrote in a newspaper article published in August 2000 was that if one goes by the numbers for the total nuclear yield put out by the Department of Atomic Energy, which I see no reason to dispute, the yield of the thermonuclear device detonated on May 11, 1998, was around 40 kilotons. This is a rather low yield."

The crux of that article was that even if one were to accept without question the DAE yield of 40 kt, there is a strong reason to believe that the thermonuclear device had not fully succeeded, Iyengar said.

Terming the test as "fully successful", AEC Chairman Anil Kakodkar and Chidambaram had yesterday said the controversy triggered by Santhanam, was "unnecessary".

Iyengar said the revelations by Santhanam, who was associated with Pokhran II, are the "clincher".

Santhanam was one of the four leaders associated with Pokhran-II and must certainly have known many of the details, particularly with regard to the seismic measurements, Iyengar said.

He said, "If he (Santhanam) says that the yield was much lower than projected, that there was virtually no crater formed, and that these reservations were formally presented by DRDO in 1998 itself, then there is considerable justification for reasonable doubt regarding the credibility of the thermonuclear test and, therefore, of our nuclear deterrent."

 

[nitesh]

Yes now there are few reason to test Nukes again,
1.Ever growing Billions dollar Aid to Pakistan (terrorists united again).
2.Anti India UN resolution on NTP.
3.Chines cunning voice on 'world without nuke',
4.OZ (japanese and others very soon) call on AP as chines territory.
5.No guarantee Russia will support India any more in UNO.
6.Narrow chances on UN expension(Indian permanent seat).

Nitesh Sir we don't distrust Indian Scientists/army capabilities. The only language world understand is the language of Power. Its better to be practically correct than politically. India is on its own ................

Please I am advocate of more tests. The whole saga is directed towards making grounds for further tests and giving room to GoI for negotiations regarding NPT and CTBT as simple as that.
Yes India was/is/will be on it's own no body will come to our aid. And this saga is the attempt towards getting India PRACTICALLY corect

 

[RPK]

NSA a ‘babe in the woods on nuclear matters’: Santhanam

Describing National Security Adviser M K Narayanan as "babe in the woods" on nuclear matters for his comments on Pokhran-II tests, former DRDO scientist K Santhanam has said his career has been that of "a cop and a spook".

Chiding Narayanan for calling him a maverick, the DRDO scientist, who was one of the four key scientists associated with the tests in 1998, said "it shows desperation of a sort. There is a nice phrase in football- attacking the player, not the ball."

"The attempt is to give the dog a bad name. But this dog has not lost its bite," Santhanam said in an interview to Outlook magazine.

Santhanam recently stirred a controversy claiming that the nuclear tests done in 1998 were not successful as projected at that time.

Terming the scientist's claims about the tests as "horrific", Narayanan had asserted that India has thermonuclear capabilities which have been verified by a peer group of researchers.

Countering Narayanan's assertion, Santhanam said, "I am a person from a nuclear background, who spent close to 16 years in Trombay, published articles in various journals. I was doing strategic analysis long before I came to Delhi. I may not be known to Narayanan but, if anything, I will add that Narayanan is a babe in the woods on nuclear matters. His career has been that of a cop and a spook. And I don't want to elaborate any further."

 

[Rajan]

Please I am advocate of more tests. The whole saga is directed towards making grounds for further tests and giving room to GoI for negotiations regarding NPT and CTBT as simple as that.
Yes India was/is/will be on it's own no body will come to our aid. And this saga is the attempt towards getting India PRACTICALLY corect

Niteshji this is a good read... press release from GoI.

PIB Press Release

If we test a nuke now this will lead huge international out-cry against India. We will totally lost what we have got from NSG and IAEA. This will also put another incredible weapon in the hand of pakistanis and chinese. They will tae all the advantages.

Dr. Santhanam wanted GoI not to sign CTBT, they are not signing but nothing more is required.

 

[nitesh]

Niteshji this is a good read... press release from GoI.

PIB Press Release

If we test a nuke now this will lead huge international out-cry against India. We will totally lost what we have got from NSG and IAEA. This will also put another incredible weapon in the hand of pakistanis and chinese. They will tae all the advantages.

Dr. Santhanam wanted GoI not to sign CTBT, they are not signing but nothing more is required.

Exactly you summed it up well. Dr. Santhanam outburst was a calculated salvo from GoI side

 

[LETHALFORCE]

India to drive tough bargain as US pushes hard for CTBT - India - NEWS - The Times of India

India to drive tough bargain as US pushes hard for CTBT


NEW DELHI: With Anil Kakodkar, secretary in the Department of Atomic Energy, and R Chidambaram, principal scientific adviser, publicly stating
that India did not need any more nuclear tests, there appears to be greater confidence and less fear of international pressure on India to sign the CTBT.

It's an issue that's been thrown up in sharp relief after US President Barack Obama led the entire UN Security Council to call for universal adherence to NPT and promised to push through the Comprehensive Test Ban Treaty (CTBT).

India will not be easily won over. It could use its indispensability to the CTBT regime to drive a hard bargain. Foreign minister S M Krishna indicated as much. Talking to reporters in Pittsburgh, he said, ``We have taken a principled stand and so the question of India revisiting it depends on a number of other developments that would address our concerns.''

Though the negotiating stance is yet to be crafted, sources said that access to simulation data with the US, which can add to the nuclear weapon knowhow, can be the starting point. Though India has maintained Pokhran II yielded enough data for computer simulation, data sharing with the US will help allay any concern that may arise if the right to test is signed away.

But so far, the government is waiting for the US Senate to actually get down to ratifying the treaty, which is proving to be extraordinarily difficult. Given the fact that Obama has a plateful of crises, sources in Washington estimate the earliest he can get this on the table will be end-2010.

Ever since India was forced into becoming part of Article XIV of the CTBT (that without India signing on, the treaty cannot enter into force), India has successfully fought off international pressure. But after the nuclear tests in May 1998, India declared itself to be a nuclear power. Famously, former prime minister Atal Bihari Vajpayee also declared to the UN General Assembly that year that India would not hold up the treaty's coming into effect.

Ironically, the recent controversy, with K Santhanam raising objections about the veracity of the thermonuclear test, threw the nuclear establishment into a tizzy. It prompted Kakodkar and Chidambaram to give the most comprehensive briefing, explaining the success of Pokhran II, stressing that India did not need any more tests.

``We have enough data. We have comprehensive simulation capability and therefore, there is no need for any more tests,'' Kakodkar was quoted as saying. Indian nuclear scientists had already validated and benchmarked the validated tool of the three-dimensional simulation for earth motion and displacement data collected following Pokhran II tests in 1998, he said. ``There is no need for a series of tests to validate the yield since the tool and also observations are available,'' he said.

 

[nitesh]

interesting read:

The Myth Bomber

 

[nitesh]

Spectral defence

S.K. Sikka, a scientist involved in Pokhran-II, shows how the U.S. calculations of yield of the thermonuclear device were way off the mark.


IN response to an article in Frontline (September 25, 2009) on the revival of the controversy over the yields of the May 11, 1998, Pokhran-II nuclear tests, one of the issues raised in informal discussions is the fact that while the fission device (of 12-13 kiloton) in the Pokhran-I test of 1974 produced a prominent crater, the Pokhran-II thermonuclear device of a much greater yield did not produce a distinctly larger crater morphology. An explanation for this is, therefore, in order.

A study of the surface topography after an underground nuclear test also provides a method to estimate the yield of the test. Western analysts have tried to use the images of post-shot crater morphology to debunk the yield values put out by the Department of Atomic Energy (DAE). The crater morphology would obviously depend on the depth of burial (DOB) and the manner of emplacement of the device in relation to the surrounding earth.

Qualitatively speaking, if the DOB is shallow a more voluminous crater is created. In an underground explosion, there are two effects: the confining effect of the material overburden causes the energy to be directed downwards and is thereby a negative influence on cratering, and at the same time the confining strata are blown upwards by the expanding gas. As the DOB increases, the confining effect obviously increases and the average material pushed upwards decreases as the mass of the overburden increases. As a result a larger and larger fraction of the material thrown upwards falls back. This also traps and buries much of the radioactivity.

At a particular depth, the increasing overburden is exactly balanced by the force of the volume being thrown out. This depth is called the optimum depth of burial and varies with the geology of the site, being greater for less dense and structurally weaker surrounding material (for example, alluvium) and shallower for dense rock.

At depths greater than the optimum DOB, the crater size begins to reduce as less and less material now gets ejected. There would be upheaval within the crater boundary but nothing is thrown out. At these depths a great amount of broken rock is produced, which was seen in the Pokhran-II thermonuclear explosion, whose DOB was about 230 metres compared with Pokhran-I’s 107 m.

The observed effects would depend on the properties of the surrounding strata and the emplacement of the device. According to S.K. Sikka, formerly of the Bhabha Atomic Research Centre (BARC) and one of the key scientists involved in the tests, the geology of the Pokhran test site is such that at depths corresponding to that of the Pokhran-I device of 1974, the surrounding material is more like alluvium, comprising sandstone and shale. But as one goes deeper the geology changes, and at depths corresponding to that of the 1998 thermonuclear device and lower the material is pink granite.

The crater sizes (depths, cavity radii, etc.) are empirically determined to be governed by a scaling law, which goes as Y0.295, where Y is the explosive yield in kt. That is, cratering explosions at different depths and yields (under similar surrounding geology) can be compared by scaling them to a standard yield, say 1 kt. For example, a 1 kt explosion at 20 m may be similar to a 50 kt explosion at 100 m. This relation has been fully characterised for Pokhran by BARC scientists. From this relation, the corresponding scaled comparisons can be made for different yields.

The Pokhran-I explosion actually resulted in a shallow crater (where the crater radius and cavity radius are roughly equal) following a raised mound with a crater radius of 47 m and a cavity radius of 30 m. Without knowing the geology of Pokhran, Western analysts have assumed the Pokhran-I test to have resulted in what is known as a subsidence crater and an equation for scaled depths (122 x Y0.295) that is not applicable to Pokhran. They also used a known value of a U.S. test which resulted in a subsidence crater, and estimated a low value for the Pokhran-I yield. For estimating Pokhran-II, they have used this low Pokhran-I yield to calibrate the Pokhran geology and estimated the thermonuclear yield to be lower.

Now, according to studies at BARC for the design yield of the Pokhran-II thermonuclear device, the DOB was exactly in the region where the crater size falls at the minimum of the scaling curve. And this is exactly what was observed. In fact, according to Sikka, exact simulations were done to eliminate completely the venting of radioactivity and the DOB was chosen accordingly. He further points out that the little mound that is seen in the picture of the cratering by the thermonuclear weapon is actually owing to the strong reflection of the shock waves from the granite stratum below the DOB.

More proof

In this revived debate over the Pokhran-II yields, Sikka has come up with yet another proof to show why Western analysts were wrong to ascribe low yield values based on seismological parameters. As explained in the earlier article (Frontline, September 25), underground explosions set up seismic waves analogous to earthquakes. These waves comprise body waves that travel through the body of the earth and those that travel along the surface. The body waves are short period (about 1-2 seconds) waves that include both compressional or P waves (which are longitudinal) and shear or S waves (which are transverse). At short distances (less than 2,000 km) body waves travel through the crust and top portion of the upper mantle and are called regional seismic waves. Beyond 2,000 km, body waves travel through the mantle and the core and are called teleseismic waves.

P waves travel faster than S waves (with speeds of about 5-10 km/s) and these arrive at the detectors first. The P-wave amplitudes are used to determine what is called the body wave magnitude m(B). The yields of explosions (as in the case of energy released in earthquakes) are given by a relation between m(B) and the explosive yield Y. This has the form m(B) = a + b log Y, where ‘a’ and ‘b’ are site-specific constants. While there is considerable variation in the ‘a’ values from site to site, variations in ‘b’ are much less.

In a paper published soon after the tests (in the September 10, 1998, issue of Current Science), Sikka and others pointed out that owing to the simultaneity of the Pokhran-II (fission and thermonuclear) explosions in shafts that were a kilometre apart, the network-averaged m(B) values would be lower than the true values because of the significant interference effects in the direction of the line joining the two shafts (east-west). They showed that if interference effects are corrected for, the averaged m(B) value was 5.39, compared with 5.0 of the Arlington-based International Data Centre (IDC) network and 5.2 of the U.S. Geological Survey (USGS) network.

They also pointed out that the constants ‘a’ and ‘b’, in the m(B)-Y relation, that were appropriate for Pokhran were those pertaining to the hard rock conditions of the Nevada Test Site (NTS) and not those of the Shagan River Test Site (SRTS) at Semplatinsk of the former Soviet Union, which were used by Western analysts. Sikka and co. reiterated this fact by a detailed analysis of 64 NTS observations and 74 SRTS observations, which was published in Current Science in 2002 (Frontline, September 25).

The earliest analyses contesting the yield claims made by the BARC scientists were those of Brian Barker and others in the September 25, 1998, issue of the journal Science and T.C. Wallace in the September 1998 issue of Seismological Research Letters. In their analyses, while Barker and co. used the IDC’s m(B) of 5.0, Wallace used the USGS’s m(B) of 5.2. Further, arguing that the observed P-wave spectrum from Pokhran-II, averaged over 20 seismic stations of the IDC network, was remarkably similar to those of tests at the SRTS, but inconsistent with those of the NTS, they applied the SRTS constants (‘a’= 4.45 and ‘b’= 0.75) for Pokhran and determined the yield to be 12-15 kt. This, according to the BARC scientists, was incorrect. Besides, Barker and co.’s paper did not provide details of the P-wave spectra or the averaging technique they had used.

Countering this, the BARC scientists sent their comments to Science, which, however, were not published. Instead, the journal sent a plot of the spectra that Barker and co. used for arriving at their assumptions regarding the constants but did not include in their paper (Figure 1). Admittedly, from Figure 1, the Pokhran curve appears closer to the SRTS curve than to the NTS curve.

Revisiting the issue now, Sikka has shown how the Pokhran-II spectrum used by Barker and co. is actually consistent with appropriate NTS constants and a yield of around 60 kt. In doing so he has demonstrated two things: one, the method of comparing network-averaged P-wave spectra is not unambiguous; and, two, careful selection of spectra should be made for choosing appropriate constants because even for a given region (NTS or SRTS or Pokhran) the geological conditions can vary from test to test depending on the depth of burial and emplacement of the device. This analysis also re-emphasises the fact that yield estimation on the basis of P-wave characteristics, including m(B), is not a precise method.

The geology of the Pokhran test site is such that at depths of around 100 m, corresponding to the emplacement of the Pokhran-I device, the surrounding material is more like alluvium, made of rocks of sandstone and shale. But at depths corresponding to the emplacement of the Pokhran-II thermonuclear device and lower, the material is pink granite. Shock physics experiments done at the Terminal Ballistic Research Laboratory (TBRL) of the Defence Research and Development Organisation (DRDO) to characterise the Pokhran granite have shown that these Pokhran rocks are very similar to the granite at the French Hogger Testing Site (HTS) in Sahara.

Fortunately, says Sikka, in 2001 J.R. Murphy and B. Barker published the P-wave spectrum of the French 58 kt ‘Rubis’ explosion at HTS on October 20, 1963. The same paper also published the spectrum of the 62 kt ‘Pile Driver’ test of the U.S. at NTS. Further, Murphy and Barker also proved in their paper that the coupling of granite with the explosive source at the NTS was close to that of the HTS granite.

Simply plotting together the P-wave spectra of Pokhran-II, ‘Rubis’ and ‘Pile Driver’, as given by Barker himself, shows the striking similarity between them (Figure 2). This is what Sikka has done in his recent exercise to drive home why Western estimates of Pokhran-II yield were lower. From the plot one can directly infer that the Pokhran-II yield would be in the ballpark of the yields of ‘Rubis’ and ‘Pile Driver’, which is around 60 kt.

Specifically, applying the constants ‘a’= 3.93 and ‘b’= 0.89, corresponding to the HTS and NTS granites, for Pokhran-II m(B) gives a yield of about 47 kt. The actual values of ‘a’ and ‘b’ for Pokhran, as determined by the BARC scientists, are 4.04 and 0.77 respectively and this gives a yield of 58 + 5 kt. The original estimate of combined yield of the May 11, 1998, tests was about 60 kt, with 45 kt for the thermonuclear weapon and 15 kt for the fission weapon that were set off simultaneously.

 

[Yusuf]

Thanks for that nitesh.

Seriously there is going to be no end to this debate. The more I think about it, the more I feel that the low yield revelations are part of the government strategy to counter any pressure to sign the CTBT.
Everyone is coming up with credible arguments. Now that the reason for a sml crater has been given, Shantanam has to come up with his counter. He infact was in charge fir preparing the test site. He should know more about DOB and also the structure of the earth there.

 

[Pintu]

Thanks and Kudos , nitesh for the article , and supporting Yusuf's view , Dr. Shantanam , should come up with credible proof supporting his arguments, else as you have said earlier and in which I agree fully it is a strategy for more rounds of test of thermonuclear device, also echoing Yusuf's view , low yield results may be part of Govt. strategy for not signing CTBT.

Regards

 

[BOSS-Is-Back]

nice one...........

 

[nitesh]

I think this hsould sooth mids of us:

No doubt about India’s nuclear deterrent: former Navy Chief

“In the midst of the current brouhaha, we need to retain clarity on one issue; given the deuterium-tritium boosted-fission weapons can generate yields of 200-500kts, the credibility of India’s nuclear deterrent is not in the slightest doubt,” Adm.(Retd) Prakash said in his article on the National Maritime Foundation (NMF) website.

While observing that the “unseemly squabbling” among the nation’s senior most scientists would certainly upset and confuse the Indian armed forces, he said “this strong, silent bulwark of India’s security has, so far, accepted the claims and statements of the DRDO (and DAE) scientist at face value and borne the operational consequences of many failed scientific projects with admirable stoicism. Will they continue to do so?”

 

[mattster]

Look guys, I am no physicist and know nothing a nuclear technology, but there is something that is extremely puzzling to my engineering mind.

If the stated goal of Pokran-II was to test a thermonuclear weapon with a 2 stage weapon where the fission part had a yield of 10-12 KT and the Fusion stage the remainder of the yield - then my question is why would anyone create a bomb with a fusion stage that only had a yield that was 3X the fission stage.

Given that the instrumentation and technology to measure stuff like this is likely to be a error-prone and fairly complex process where so many things could go wrong - I would think that if you really wanted to prove your Fusion stage worked, then you would have a 1X fission stage triggering a 10X fusion stage. ( a 110 KT weapon as opposed to a 45 KT weapon)

In such a scenario even if 2 different teams of instrumentation specialists disagree on the result or the exact number for the yield - you would still be conclusively able to say weather the fusion stage worked or fizzled out.
Even if there was a 1X or 2X margin of error caused by faulty measurement instrumentation or faulty analysis, etc - there would still be an 8X overhang on the test results to prove that the device worked.

But by creating a device where the Fusion stage is just 3X the yield of the Fission stage - you have basically reduced your margin of error for your measurement to a tight window.

Can someone with a background in nuclear physics tell me if my simple brain is making this too simplistic.

 

[Yusuf]

Look guys, I am no physicist and know nothing a nuclear technology, but there is something that is extremely puzzling to my engineering mind.

If the stated goal of Pokran-II was to test a thermonuclear weapon with a 2 stage weapon where the fission part had a yield of 10-12 KT and the Fusion stage the remainder of the yield - then my question is why would anyone create a bomb with a fusion stage that only had a yield that was 3X the fission stage.

Testing of higher yields would throw up radiation and violate the Partial test ban treaty rules. That is why they say that the design tested is scalable to 200KT.

 

[mattster]

Testing of higher yields would throw up radiation and violate the Partial test ban treaty rules. That is why they say that the design tested is scalable to 200KT.

Come on......India was already violating everything that we could violate when we decided to test - So if you are already breaking the NPT laws; you might as well break them all the way and get the results you want.

I dont buy that at all.

 

[Yusuf]

India is not a signatory of the NPT. So it violated nothing by testing. But it is a signatory of the Partial test ban treaty and adhered to it.

 

[nitesh]

salvo from other side

http://www.expressbuzz.com/edition/...yc=&SectionName=aVlZZy44Xq0bJKAA84nwcg==&SEO=