But we do not know the empirical constants for Pokhran.Prem Kumar wrote:Mb = 4.262+0.973 logY
Kang et al do not know the constants for NoKo.
But we do not know the empirical constants for Pokhran.Prem Kumar wrote:Mb = 4.262+0.973 logY
Mail sent, but probably reply tomorrow too late now. Gnite.ShauryaT wrote:My message to you on this board was deleted.
India's nuke delivery system flawed, show scandals
George Koshy / CNN-IBN
Published on Wed, Sep 02, 2009 at 02:17 in India section
The doubts extend to delivery systems. India's Agni II missile was declared operational after two tests. The Agni III missile has been tested three times as it failed the first time.
Nuclear bums are to be never used. Else the junior adversary in the exchange will get totally annihilated, at the cost of the senior adversary losing say 80% of his capability and population.Masaru wrote:Sorry if already posted, but the signs look ominous of late.
Pakistan rapidly ramping up India-specific nuclear arsenal
The 3 tests conducted on 11 May, 1998 were with a fission device with a yield of about 12 kT, a thermonuclear device with a yield of about 43 kT and a sub-kilo tonne device. All the 3 devices were detonated simultaneously. It may be noted that the yield of the thermonuclear device tested on 11 May was designed to meet stringent criteria like containment of the explosion and least possible damage to building and structures in neighbouring villages. On 13 May, 1998 two more sub kilo-tonne nuclear tests were carried out. These devices were also detonated simultaneously. The yields of the sub-kilo tonne devices were in the range of 0.2 to 0.6 kT.
The tests conducted on 11 May as well as on 13 May were fully contained with no release of radioactivity into the atmosphere.
The measured yields of the devices agree with expected design values. A complex software package developed by DAE has been used in device design and yield estimation.
The tests conducted during 11-13 May, 1998 have provided critical data for the validation of our capability in the design of nuclear weapons of different yields for different applications and different delivery systems. These tests have significantly enhanced our capability in computer simulation of new designs and taken us to the stage of sub-critical experiments in the future, if considered necessary.
Press Conference with Weapons Scientists, 17 May
Press Conference, Shastri Bhavan, India, 17 May 1998; available on the Government of India web-site. http://www.indiagov.org,
"Question: 'How near is the thermonuclear device to a hydrogen bomb? What was the material used for the fission trigger?'
Dr. R. Chidambaram, Chair, Atomic Energy Commission (AEA): 'The hydrogen bomb is the popular term. In a hydrogen bomb there is a fission trigger and separately there is also thermonuclear material which requires appropriate configuring. It is therefore a two-stage device. The secondary stage provides the major yield. The range can go quite high but we were limited in the total yield by the damage it may cause to habitations nearby. We are not revealing the materials used.'
Question: 'When were you told to go ahead with the tests?'
Dr. A. P. J. Abdul Kalam, Secretary, Department of Defence Research and Development: 'T[est] minus 30 days.'
Question: 'Are we now moving towards subcritical, hydronuclear, hydrodynamic and computer simulation [testing], including laser fusion techniques such as those in the National Ignition Facility in the US?'
Dr. Chidambaram: '... We are aware of the US programmes for Inertial Confinement Fusion, where you hit a pellet with laser beams and simulate some kinds of phenomenon. We have done what we have done.'
Question: 'Does India have a deliverable weapons system right now?'
Dr. Kalam: '... This is a National Mission. PM [Prime Minister] has said that India is a NWS [nuclear-weapon State].'
Question: 'Will sanctions affect [your work]?'
Dr. Kalam: 'Technologically, we have faced sanctions for a long time. When we were refused the supercomputer, we went ahead and made our own. In the space programme, when we were refused cryogenic engines, we have gone ahead and made our own which should be ready next year. No one can trouble us technologically. There is a challenge to be met and we rise to the occasion."
Question: 'How far is the nearest village?'
Dr. Chidambaram: 'A little over 5 km away - Khetolai. Our total yield was set by this."
Question: 'Where is India in nuclear weapons technology today?'
Dr. Kalam: 'The 3 tests on 11 May - the hydrogen bomb, the fission device and sub-kiloton device - as well as the two subsequent sub-kiloton device[s] have proved clearly that our nuclear weapons technology has achieved a stage of self-reliance. If there is a demand for it, we shall do it.'
Question: 'What was the logic behind simultaneous detonation?'
Dr. Chidambaram: 'The two devices - the thermonuclear and fission device - were 1 km apart. We needed to make sure that the detonation of one did not cause damage to the other, since the shock-wave has a time-travel in milliseconds. So we went in for simultaneous detonation. It was also simpler - use one button to blow three. We had close-in seismic measurements and accelerometer data also.'
Question: 'What fraction of the hydrogen bomb energy is due to the thermonuclear part? What was the cost of the tests and weaponization?'
Dr. Kalam: 'As regards cost, this dies not amount to huge amounts. These costs were met from the budgets of our respective departments, over and above what we apportion for regular activities.'
Dr. Chidambaram: 'As regards what fraction - the total was 45 kilotons. The fission trigger was equivalent to that of the fission device.'
Question: 'Can these nuclear warheads be fitted on Privthi and Agni?'
Dr. Kalam: 'The missiles we have can carry any type of warhead, conventional or nuclear, depending on the weight, size and environmental specifications. The missiles are only carriers, they can even carry flowers.'
Question: 'Do we have the technology to gauge the size and power of Pakistan's bomb?'
Dr. Chidambaram: 'Before or after they detonate? Of course we have methods of detecting their tests using teleseisometers. I have no idea of their programme. I have never been to Pakistan. In our tests the waveforms recorded have been confused because the detonations were simultaneous. ...'
Question: 'Is the Agni project now to be further developed?'
Dr. Kalam: 'If needed, we can make it in the numbers required. The ranges can be adjusted, if needed for higher ranges.'
Question: 'From your 5 tests you have collected data. Can development now be done within the ambit of the CTBT?'
Dr. Chidambaram: 'Good question. But no comment.'
Question: 'How long have scientists been ready?'
Dr. Chidambaram: 'Since 1974 we have had the knowledge. The technology and knowledge has been undergoing improvements and refinements.'
Question: 'Did you specifically prepare the tests so that they cannot be detected?'
Dr. Chidambaram: 'No.'
Question: 'But not even by the CIA?'
Dr. Chidambaram: 'You must ask the CIA.'"
You are so right, I just looked up, it has been reconstituted. Current members:ramana wrote:Its there but as an advisory body it exists to keep the Western think tanks think they are like us onlee.
There are 28 members drawn from various professional backgrounds in the NSAB. They include Shri KS Bajpai, former Foreign Secretary (Chairman), Prof Shankar Acharya, former Chief Economic Advisor to the Govt of India, Ms Sobhana Bharatia, Chairperson, Hindustan Times, Shri Naresh Chandra, former Cabinet Secretary, Shri HK Deka, former Director General of Police, Assam, Dr Nitin Desai, former Deputy Secretary General of the United Nations Organization; Shri HK Dua, Chief Editor, The Tribune; Dr Prodipto Ghose, former Secretary, Ministry of Environment and Forests; Prof PS Goel, Indian Space Research Organisation; Vice Admiral KK Nayyar; Shri SC Mehta, former Special Director, Intelligence Bureau; Admiral Arun Prakash, former Chief of Naval Staff; Prof V Ramamurthy, Chairman, Indian Institute of Technology, New Delhi; Dr P Rama Rao, Member, Atomic Energy Commission, Gen Aditya Singh formerly the GOC of Southern Command; Former Air Chief Marshal SP Tyagi and Shri PKH Tharakan former Secretary (R&AW)
Villages near India's nuclear tests site have no reason to celebrate
[ Peace ] by sapw @ 11.05.2008 04:18 CEST
[Today 10 year after India's Nuclear tests in Pokharan in Rajasthan, there is no reason for the ordinary people to celebrate. The villagers near the test site who have lived with radioactivity in the desert air and environment hardly matter to the powers that be. After the first nuclear test explosion at Pokhran in 1974, some of the wells in the area were sealed by the DAE. Water samples are reported to have been collected at regular intervals, by the offcials, but villagers have been prevented from using these wells, but without being given any reason. After the second series of experiments in 1998, water from a tube well in a village 7 km south of Pokhran, became jet black. Reduction in yield and fat content of milk was reported from the neighbouring villages. Radioactivity would have certainly penetrated the underground water and ground beneath. The gases and particles vented out during blasts would have been carried away by the desert wind. Not much written that is easily available. In 1999, Kalpana Sharma a well known journalist had written an interesting article - "Khetolai: The forgotten village", The Hindu Survey of Environment 1999. (pp.17-19) . See also Gadekar, S. 2000. The Smile that makes Generations Sick, in Lokayan Bulletin (Exploding Peace: Peaceful Nuclear Tests. 15.1/6 – July-June 1999-2000), New Delhi. (Pg. 91-93); Makhijani, A. 1999. Making the Bomb – Without Consent, With Injury. The Hindu Survey of the Environment 1999. (Pg 21-27)
Posted below are two news reports from today's papers in India -SAPW]
Nuclear history lost on local village
by Siddhartha S. Bose, Hindustan Times
Khetolai (Pokhran), May 11, 2008
Pokhran’s historic moment is lost on the people of Khetolai, the last human habitation near the nuclear blast site of 11 May, 1998. The young in this village vaguely recall the day when the blasts catapulted India into the orbit of countries with nuclear capabilities. The elderly take it with a pinch of salt.
“It took place on our land and made history. But what did it give us?” asks Ramlal, a schoolteacher in the local senior secondary school. Pokhran is 26 km from Khetolai; the 1998 blasts took place just 3 km from the village. A vast stretch of forbidden desert expanse separates the village from the heavily guarded blast site on the other end.
The villagers have lived on promises made to them by the Centre and the state government after the blasts.
Ten years have gone by and the promises still remain unfulfilled! And yet, the 250 odd families that live with a high literacy rate of 80 per cent and have a third of their adult population serving as government teachers, rarely discuss the atomic blasts with their children.
“Our livestock suffered from the radiation during initial days, fissures opened up in every single house in the village after the tremors that followed the blasts. The government made almost a tourist place out of Pokhran but locals suffered,” Ramesh Chand who grew up in Khetolai said. He has moved out of the village to work in nearby Phalodi.
Lt Colonel NN Joshi, army spokesperson based in Jodhpur, said the Defence Research and Development Organisation (DRDO) were going to celebrate the occasion as National Technology Day. “We have received a recent communication which holds up the day as a symbol of technological empowerment,” he said.
Ramlal says people take pride in the event but are disconnected from it. How would the younger generation relate to the incident, he ponders, adding: “If only the government would have given us a desperately needed hospital in Pokhran and named it Shakti Sthal (name given to the blast site), the children would have known.” Khetolai has a primary health centre but doctors come there rarely, allege villagers. Army doctors don’t cater to the local population.
Far from being obsessed with Pokhran, people here have learnt to live with the army watching over them on three sides. The sandy stretch separates the village from the watchtowers guarding the ’98 blast sites. People are forbidden from wandering into the area. Visitors are allowed till only a km ahead of Shakti Sthal.
----
10 yrs on, Pokhran to have a war museum
by Vimal Bhatia & Prakash Bhandari (Times of India, 11 May 2008)
POKHRAN: Ten years ago, on May 11, 1998, the Buddha smiled once again in the deserts of Rajasthan as the country undertook a series of nuclear tests in the Pokhran field range. The first-ever nuclear test by the country, code named ‘Smiling Buddha’, was also conducted in the same place on May 19, 1974.
The area of the tests is still kept under tight security. There are four gates spread over a 3.5 sq km area. The first is known as Kohinoor Gate and the last, Bhoochal Gate. But soon, footfalls in the sands which saw India’s strategic coming of age could increase as the government goes ahead with plans to set up a war museum in the Pokhran range.
"We are trying to set up a model of the Khetolai village in Pokhran where the blasts took place. A war museum would be set up here and the help of the Army and BSF has been sought to set up the museum," said Ambarish Kumar, district collector, Jaisalmer.
[...].
ShauryaT wrote:KS's charge that the TN worked to maybe about 60% of the desired yield, matches with the 43 KT declared yield and also matches with the global 5.2 magnitude averages.
Arun_S, ramana: I had this question before, do you see a difference in what PKI said and what KS says. Can both be right?
My understanding is, it is the former. By memory, I remember PKI saying only 10% of the second stage was burnt (partial burn). So, does that add up, if you add the primary+spark+secondary?ramana wrote:ShauryaT wrote:KS's charge that the TN worked to maybe about 60% of the desired yield, matches with the 43 KT declared yield and also matches with the global 5.2 magnitude averages.
Arun_S, ramana: I had this question before, do you see a difference in what PKI said and what KS says. Can both be right?
How does that reconcile with the reduction to limit potential damage to civil structures?
Is KS saying 60% of 43kt? or is 43 kt, 60% of something?
If its former than that is PKI stance.
He is just guessing, since he doesn't know design details.Parts of interest from Dr.Iyengar's article are quoted below, and an analysis is attempted with the help of the previous section.
"The thermonuclear device had two parts: a `boosted-fission' trigger, and the actual thermonuclear part. The boosted-fission trigger would have yielded at least 20 kilotons, which means the thermonuclear yield of this device could only be around 20 kilotons. About 400 grams or only around 500 ml of LiDT is needed to produce this much energy."
400g of LiD (with a volume around 500cc; actual specific gravity of LiD at normal temperature and pressure is ~0.9) with a yield of 20kT gives an energy content of 50kT/kg (which corresponds to ~45% enriched Li-6). It is evident here that Dr.Iyengar has used a fusion efficiency of 100% to calculate the amount of LiD needed for the fusion yield of 20kT. If the BARC designers had designed for an efficiency of 50%, the probable mass of LiD would be 800g (1000cc). With a 'more realistic' design efficiency of 20% for a first generation thermonuclear weapon, probable mass of LiD is ~2kg (2500cc). The important point to note is that a 20kT yield with 400g of LiD is for an ideal case of 100% burn - in the real design, there are bound to be allowances for lesser efficiencies by using more LiD to yield the same 20kT. The caveat here is that this real design would have to ensure that the larger amount of fuel is uniformly compressed and heated i.e., merely adding more LiD to an existing design doesn’t automatically lead to a higher yield.
"In my judgment, this is a very small volume for the core of the fusion secondary. It, therefore, seems that the secondary (fusion) device burnt only partially, perhaps less than 10 per cent. To get any burn at all in such a complex device is in itself a significant achievement, but clearly the next step would be to improve the device to get greater burn, leading to greater efficiency and smaller size."
Dr.Iyengar proposes here that the actual design yield for fusion was perhaps around 200kT (for 4kg or 5000cc of LiD with 100% efficiency), with the secondary achieving a 10% burn for an actual yield of 20kT. One is not aware if there are other reasons (undisclosed to the public) for assuming an efficiency of less than 10%. However if the reported low volume of LiD (~500cc) calculated for 100% efficiency is the only consideration, the higher mass/volume of LiD for the realistic efficiencies of 50% or 20% calculated previously would pre-empt any such objections. Thus there is no reason to suppose that the 20kT (or ~30kT as suggested by later BARC reports) fusion yield was not close to the actual design yield.
I agree, you are right, my mistake. I see muddy water come through as well, even through municipal water supply. There seems little basis to claim that any significant radioactivity leaked, or they would have far worse problems show up in 10 years than "reduced milk output of the cows". The cordoned-off area is probably the limit of any radioactivity danger. Although there are some vague hints about radioactivity in the villages, there are no credible claims except one, where a senior scientist is cited as saying that he suspects that there is left-over plutonium from some blast - was POK-1 Plutonium? There is some claim of high incidence of birth defects of some sort, I think.Ground water may turn black/brackish due to any number of reasons.
Anyway, if there were radioactivity either from POK-1 or 2, high incidence of cancer would have shown up by now. Shows that the safety precautions were well thought-out - not haphazard.[FROM THE REUTERS NEWS SERVICE, MAY 17, 1998]
New Delhi, India: Several residents of a village near India's nuclear-testing site have complained of nose-bleeds, skin and eye irritation, vomiting and loose bowels since last week's underground blasts, a report said on Sunday.
The government has said that no radioactivity was released into the atmosphere over the Thar desert, in the western state of Rajasthan, as a result of its five tests.
But The Sunday Statesman said that more than a dozen people from the village of Khetolai experienced symptoms of contamination by radiation immediately after the last two of the five devices were exploded on Wednesday.
`The residents approached us, gave a list of affected persons,' the paper quoted a district official as saying. `Most of them have complained of nose-bleeding, loss of appetite, irritation in skin and eyes.'
`We will soon send a team of doctors to examine the affected villagers. Only then can we come to a conclusion. It could also be due to the rise in temperature,' he said.
The paper said the people of Khetolai were convinced that the complaints were due to radiation exposure and quoted one man as saying he was suffering nose-bleeds for the first time in his life.
Another man was worried about his 12-year-old daughter. `She has been vomiting, bleeding through the nose and feeling restless for two days after the second explosion,' the paper quoted the girl's father as saying. `First we ignored it but when the number of victims rose we brought it to the notice of district and army officers.'
Khetolai is one of seven villages dotted around the Alpha Firing range of the area called Pokhran.
"not more than 60 % successful in terms of yield"I have maintained and will always maintain that the test was not more than 60 per cent successful in terms of the yield it generated. I have made this assessment based on the report of the instrumentation data that is available and also the programme coordinator.
By the very nature of strategic importance of nuclear weaponry, it is obvious that certain data are classified information. It appears that until and unless the ‘sensitive’ data are declassified and available in open literature, arguments and counter arguments on nuclear yields will continue to be open-ended.
How far back does that "have" go?I have maintained
I have maintained and will always maintain that the test was not more than 60 per cent successful in terms of the yield it generated.
The new revelation by Dr. Santhanam is that the actual total yield of the thermonuclear device (i.e. the boosted-fission part plus the fusion part) was only 60 per cent of the design value (of 50 kt), i.e., around 30 kt. This is also consistent with the yield values obtained from seismic data according to international sources.
It is true that the subsequent drilling operations and radioactive measurements have shown the presence of fission fragments and isotopes produced by fast neutrons. But these fast neutrons could have come from, the fission as well as the fusion. Further, the booster itself has tritium which would have contributed to the activity generated by fast neutrons. Therefore presence of these isotopes cannot unequivocally confirm that the fusion secondary has really worked. Attempts have also been made to derive the fusion yield from a radiochemical analysis of the isotopes.
However, the methodology employed in the radiochemical analysis, is complex. Approximations made in integrating the flux distribution, extent of the cavity, and a statistical variation in the samples taken by drilling, introduce large error. Nobody can vouch for the geometry of the cavity or their debris. BARC scientists have themselves indicated an error of 40 per cent on their number of 50 kt. Under this circumstance, this radiochemical method is not absolute proof for the yield of the explosion.
That is the crux of the matter. Read PKI's latest. And as I predicted a few pages ago the Radio-Chem is going to get scrutiny.If they were able to hit their own targets precisely, there is reason for confidence. OTOH, it is a solid argument to reject CTBT, FMCT etc, unless there is an agreed provision for India to test what is needed to be proven for a minimum credible deterrent.
Number 2. It will be in the outer range of the seismic evidence of 5.2 magnitude, global averages. Also, this number may matchup the Primary+spark+partial burn that PKI has claimed.shiv wrote:1) The yield was 43 kT but it was supposed to have yielded 72 kT
2) The yield was 26 kT but it was supposed to have yielded 43 kT
3) Some other meaning - like the number of neutrons produced was not enough, or the primary broke up before the total yield was achieved
Would you agree then that there was never any intention to test a 150 or 200 kT device and that the design was of a device that would yield about 45 kT? India tried to test a Thermonuclear device that was supposed to yield 45 kTShauryaT wrote:Number 2. It will be in the outer range of the seismic evidence of 5.2 magnitude, global averages. Also, this number may matchup the Primary+spark+partial burn that PKI has claimed.shiv wrote:1) The yield was 43 kT but it was supposed to have yielded 72 kT
2) The yield was 26 kT but it was supposed to have yielded 43 kT
3) Some other meaning - like the number of neutrons produced was not enough, or the primary broke up before the total yield was achieved
I know that for Bhagalpur Ke PeeHd ka bachha should go back to sher shaayari rather than try and understand ML Khanna books. ( to make his sher shayari authentic wear Sherwani and under se pareshani, can chew a pan and sit next to wall for easy,,,)Bulletin of the Seismological Society of America; August 2002; v. 92; no. 6; p. 2381-2390; DOI: 10.1785/0120010214
© 2002 Seismological Society of America
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Article
The Effect of Synchronized Multiple-Cavity Sources on Seismic Radiation
Matthias G. Imhof and M. Nafi Toksöz
Department of Geological Sciences
4044 Derring Hall (0420)
Virginia Polytechnic Institute and State University
Blacksburg, VA 24061
(M.G.I.)
Earth Resources Laboratory
Department of Earth, Atmospheric, and Planetary Sciences
Massachusetts Institute of Technology
42 Carleton St.
Cambridge, MA 02142-1324
(M.N.T.)
Interference among seismic waves radiated by multiple but identical sources arranged in a tight pattern can alter the individual radiation signatures, which can mask the original nature of the source. The pattern for the combined events may even resemble the pattern for a different type of source. Another mechanism to change the signature of a seismic event is scattering near the source. For example, manmade sources embedded in the subsurface need some means of access and placement, such as a tunnel or borehole. Additional hollows may be located nearby to site instruments or other sources. Relative to the surrounding material, all of these cavities may constitute large impedance contrasts that very efficiently scatter and convert seismic waves of comparable wavelengths.
To examine these effects, we calculate radiation patterns for a number of models consisting of two or three cavities with one or multiple explosive sources located inside the cavities. We illustrate the importance of distance between the cavities and exemplify the effect of synchronized sources by time-delaying multiple explosions. We observe that careful selection of distance and delays alters the radiation pattern, which might allow synthesis of a radiation pattern, to boost radiation in a predetermined direction or to make the pattern resemble the radiation from another type of source.
vera_k wrote:^^^
#2 above is the correct interpretation. This matches the total yield of 25KT claimed by Douglas & co in their papers published in Current Science.
Those papers did not arrive at a conclusion and the process ended with this statement from the journal.
By the very nature of strategic importance of nuclear weaponry, it is obvious that certain data are classified information. It appears that until and unless the ‘sensitive’ data are declassified and available in open literature, arguments and counter arguments on nuclear yields will continue to be open-ended.
(above quote sourced from http://www.globalsecurity.org/wmd/world/india/links.htm )Making waves By Debora MacKenzie NEW SCIENTIST 13 June 1998 -- Although India said it exploded 60 kilotons in its first test, the seismic stations recorded only 25 kilotons. However, Roger Clark, a seismologist at the University of Leeds, found that when data from 125 stations--closer to the number required by the treaty--are taken into account, the estimate is nearer to 60.
For the tested TN, it seems to be the most probable answer. At this time, I am simply trying to triangulate KS, PKI and the NPA claims.shiv wrote: Would you agree then that there was never any intention to test a 150 or 200 kT device and that the design was of a device that would yield about 45 kT? India tried to test a Thermonuclear device that was supposed to yield 45 kT
P K Iyengar
First Published : 02 Sep 2009 12:44:00 AM IST
The recent controversy that has erupted regarding the 1998 Shakti or Pokhran-II tests, after the statement of Dr. K. Santhanam about their yield, has once again brought into focus the need for further nuclear tests in order to have a credible nuclear deterrent. The issue gains fresh stimulus because of the expectation that the new US Administration will get the Comprehensive Test Ban Treaty (CTBT) ratified by the US Congress, and put pressure on India to sign it. The pressure may be more difficult to withstand this time, compared to 2000, because of expectations and complications arising from Indo-US Nuclear Deal.
There may be political arguments both for and against signing the CTBT, and for maintaining a credible nuclear deterrent. But, once we have decided on a policy of nuclear deterrence, which will require weaponisation, then, scientifically, we have no option but to continue testing. It is the scientific case that I wish to make here.
To refresh people’s memories: three nuclear devices were detonated simultaneously on May 11, 1998: a pure fission device, a thermonuclear device, and a sub-kiloton fission device. The pure fission device was similar to the Pokhran-I device, and was reported to have a yield of 15 kt. A typical thermonuclear device has two parts: a ‘boosted-fission’ trigger, and the actual thermonuclear part, comprising LiD fuel. The fission trigger is an atom bomb that produces enough radiation pressure to make the ‘hydrogen bomb’ ignite. In addition, one can use a spark-plug; this spark-plug is just some fissile material like plutonium (Pu) placed around the fusion core which, when it fissions, heats the core and aids the fusion process. The first hydrogen explosion, Mike, carried out by the US in 1952, had a spark-plug. It is very likely that the thermonuclear device of 1998 also had a spark-plug.
Therefore, the total yield of the thermonuclear device is the sum of the fission yield from the boosted-fission, the fission yield from the spark-plug, and the actual fusion yield from the LiD. The latter proceeds by the Li first being converted to tritium by absorbing a neutron arising from the fissions, and this tritium then fusing with the deuterium (D) to form helium (He).
Now, if one goes by the number for the total nuclear yield put out by the Department of Atomic Energy following the 1998 nuclear tests, the thermonuclear device alone was around 50 kilotons. To know how successful the fusion was, we must know how much of this came from the boosted-fission and spark-plug, which are fission reactions, and how much from the actual fusion of tritium to form helium. In earlier designs the booster has been designed for as much as 45 kt yield, so if we take the booster yield as even 30 kt, a reasonable assumption, then the fusion yield must have been 20 kt. One can then calculate that the amount of LiD that must have burnt to achieve this yield would be 400 grams or only around 500 ml. This is small volume, and typically one puts in a lot more of the fusion material in the core — in kilograms. Therefore, if only 400 gm burnt, then the fraction the total fuel that burnt must have been small — perhaps as little as 20 per cent. Clearly, this is not a very efficient thermonuclear device. Now, the unburned LiD fuel would still have been converted to tritium by the capture of neutrons. If most of this tritium did not ‘burn’, i.e. fuse to form helium, then a lot of tritium should have been detected in the soil samples from the test site. This is what seems to have happened, even though it is not confirmed.
The new revelation by Dr. Santhanam is that the actual total yield of the thermonuclear device (i.e. the boosted-fission part plus the fusion part) was only 60 per cent of the design value (of 50 kt), i.e., around 30 kt. This is also consistent with the yield values obtained from seismic data according to international sources. If we accept Dr. Santhanam’s number, coming as it does from one of the core members of the Pokhran-II tests, then the situation is even more serious. This suggests that the thermonuclear burn may have been marginal or may not even have occurred at all. This has very serious implications for our weaponisation programme and deterrence philosophy, and certainly invites much closer, detailed, technical scrutiny. Of course, none of these numbers are very accurate, but 10 kt more or less, in one direction or the other, will not materially alter these conclusions.
It is true that the subsequent drilling operations and radioactive measurements have shown the presence of fission fragments and isotopes produced by fast neutrons. But these fast neutrons could have come from, the fission as well as the fusion. Further, the booster itself has tritium which would have contributed to the activity generated by fast neutrons. Therefore presence of these isotopes cannot unequivocally confirm that the fusion secondary has really worked. Attempts have also been made to derive the fusion yield from a radiochemical analysis of the isotopes.
However, the methodology employed in the radiochemical analysis, is complex. Approximations made in integrating the flux distribution, extent of the cavity, and a statistical variation in the samples taken by drilling, introduce large error. Nobody can vouch for the geometry of the cavity or their debris. {Arun_S: And they based that "shadow of radio-chem paper" by drilling only 2 holes !!! Instead of using Radio-Chem for precise yield measurement, BARC used the paper to only prove that some Fusion did happen. They OTOH spent pathetic little effort to measure the radius with any precision (just an estimate that gives yield variation of more than than 80%) determining radius of the cavity, and the yield is function of Radius^3 {i.e. cube}. Further they state additional 20% error in determining of fusion yield, where in fact there is no room for the 20% error, because those variations can be eliminated by simple process they have in their hand. ) BARC scientists have themselves indicated an error of 40 per cent on their number of 50 kt. Under this circumstance, this radiochemical method is not absolute proof for the yield of the explosion.
Conduct more tests
Because of these considerations, I have held the view that we should repeat this experiment, especially the thermonuclear part, to have full confidence that the secondary has been ignited and not simply triggered. In a fusion device the burn, if properly ignited, is continuous in the volume of the secondary and therefore the efficiency of the fusion system should be higher. Since that is not well established, logically and scientifically it is better to conduct more such tests to establish the results and to achieve greater efficiency.
When we go from testing a device to weaponising it, there will be a lot of changes in the hardware configuration, because it has to match with the delivery system – either a missile or an independent bomb. Weaponisation also means certifying to the user the yield and reliability. More gravely, we must be able to convince not just ourselves but the entire world that we have mastered the thermonuclear weapon, and are fully capable of deploying it.
If there is any uncertainty in their minds regarding the efficacy of our nuclear deterrent, the entire concept of deterrence fails. This assumes even greater importance since we have declared a ‘no first use’ policy. It is unscientific to embark on a long programme of weaponisation, and develop elaborate plans for maintaining a credible nuclear deterrent, all based on just one, low yield, thermonuclear test. When we do not do this for the Agni or Prithvi missiles, or even the Nano car!, why would we want to take this risk for nuclear weapons?
I am sure that the BARC scientists themselves, like their DRDO counterparts, would prefer to take a more conservative approach and test further to refine their designs and their capabilities. This is the scientific way. It would be wrong for the government to pressure the scientists to put a premature end to nuclear tests, for political expediency.
On top of all these uncertainties, we have the political pressure for India to sign the NPT, the CTBT, and the FMCT. Whatever the Government may claim, it is unlikely that a future government can ignore the assurances given by the present Government, or afford to withdraw from these treaties, after establishing the very capital-intensive nuclear power programme, with foreign investment. It therefore requires a systematic and deeper study to plan a long-term strategy, keeping in mind that the number of countries with nuclear weapons is only likely to go up, and the weapon powers are unlikely to agree for universal nuclear disarmament.
Arguments for CTBT
Technical arguments for signing the CTBT often run as follows: we have confirmed the validity of our computer simulations using data from Pokhran-I and Pokhran-II. These computer codes can therefore be used to design nuclear weapons. If any further changes are made to these computer codes, we can revalidate them using sub-critical tests that are not barred by the CTBT. Therefore it is OK to sign the CTBT.
First, it should be remembered that of the total of six tests, five were fission devices, and only one was a fusion device. The physics of fission and fusion devices, and hence the computer codes used to model them, are very different. Therefore, for the fusion device, we really have only one test, that too of doubtful success, with which to check the computer simulation.
One is an alarmingly small number. In any case fusion (and, for that matter, fission) devices are extremely complex systems with a large number of variable parameters. It is unwise to benchmark a computer simulation of a full-scale explosion using data from just one test. Sub-critical tests are no substitute for full-scale tests, especially when we talk of weaponising. This is all the more so, because of the disastrous consequences of even one failure. Therefore, if we want to weaponise we cannot depend on computer simulations alone: we have no option but to test further.
I would like to emphasise that thermonuclear devices are better for weaponisation and deployment, because they are compact, light, use less sensitive material, and offer better safety features. For example, a boosted-fission thermonuclear device can be as light as 200 kg, compared to a pure-fission device that can weigh as much as 800 kg for the same yield.
It is for this reason that most of America’s nuclear weapons are fusion weapons. Therefore my focus here has been on the inadequacy of just one thermonuclear test, of low yield, for weaponisation. If the Americans are pressuring us to sign the CTBT, it is precisely for the reasons stated above: one could thus freeze India as a non-weapon country.
Credible deterrent
Given the earlier doubts on the yield raised by many experts, and now by Dr. Santhanam,
given the need to evolve an efficient thermonuclear device with a large burn percentage, given the necessity of hardware changes that are needed to match with the delivery system, and given the need to convince the world and particularly potential enemies that we have mastered all aspects of the thermonuclear weapons and have a credible nuclear deterrent, it is a scientific imperative that we should test not just once but repeatedly.
To blind oneself to this imperative could be disastrous. We would do well to remember what the famous American physicist, Richard Feynman, said in the report on the 1986 Challenger shuttle disaster: “For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled.” Nor can the world.
The proof for the statement that such a design was fixed is non existent in public sources. Like the conflicting public statements of various parties - this is yet another one that adds to the fog.Anant wrote: By fixing it, do you mean that the design was fixed in 2003 to correct for errors based on the test in 1998? Thank you.
Possible but then you have to discount what KS said? Unless, KS still meant 60% of 43kt. It also means TN was a massive failure and RC was not just mistaken or ego driven but mad to come and claim this and ALL of BARC committed treason .... the only other explanation is all this is Maya, that we do not understand like a secret order from APJ to RC.ramana wrote:I don't. The weapon tested was 200kt. However when the crater turned up small RC said ti was 43 which is the desgin (Pry+sparkplug+ secy) yield. Subsequent seismic data showed it was even less. And radio chem was bunkum. If you take the tolerances they say for the radius of cavity it too comes to ~27kt max.
However they have fixed all this by 2003. Not earlier.
Post Diwali any clarity.
Vera - may I point out a fudge here?vera_k wrote:Time to test again BARC scientists have themselves indicated an error of 40 per cent on their number of 50 kt.
The propagation of these errors leads to an overall error on the measured yield which is around 20%. Thus it is concluded that the total yield of the thermonuclear device is 50 (+/-) 10 kT.