Pokhran II not fully successful: Scientist - Part-3

[shiv]

Gagan - I think you would know the medical adage that when there are many possible ways to treat a specific disease it means that none of them is the best - each one is suited to a particular set of circumstances.

The same appears to be true about TN devices - with different sets of people picking up what suited their technical capability, engineering and availability/purity of material to arrive at some via media that they felt would be suitable for them.

The fact that PKI talks about various designs that were considered and similar talk of many different designs being available for testing (in various post 1998 reports) suggests that different groups of people facing the same set of problems are constantly on the lookout for solutions that suit them. If your problems are different from what others face, your solutions are likely to be different. And surely there will be strong differences of opinion about what is "best". This is profoundly true in the medical field and I can write a chapter on facets of this and it is the same for every branch of science where you cannot cut and paste the circumstances of X into country Y and then apply the solutions of X on Y without modification.

India strategic thought was asleep in 1962 and received a second jhatka in 1964 and a third jhatka in 1965. It took 10 years to clear some of the fog as old fogeys passed away and India tested in 1974. And after that the Indian establishment has faced a problem that no member of the P5 has faced - i.e to develop a credible/working arsenal in the absence of testing.

There are two separate aspects to this and we usually get mired down in one and mix up the two:
1) The political aspect: Why did we not test? Why could we not have the guts? Why can't we be like China? India is wealthy enough. Leaders are blind, dumb, deaf, stupid, scared etc.

But this aspect is completely separate from the problems faced by the science establishment

2) The scientific burden: For the people in the program the problem was technical. How to develop bombs surreptitiously and make them credible without testing while working under constraints of lack of funds and lack of material (and of course, sanctions after 1974).

The point I am trying to make here is that the people who had to build a bomb had to do so whatever the hurdles and they could not argue like we do: Why can we not test? Why do we not have the guts? Why can't we be like China? India is wealthy enough Leaders are blind, dumb, deaf, stupid, scared etc..

Faced with such hurdles it is likely that the Indian establishment has come up with its own solutions which may or may not be like anything that we know about by studying similar programs conducted by the P5. Too many people take a fractal recursive path and don the mindset of the colonizer/sanctions giver and become scathing critics of our own people for not following the path of the colonizer/sanctions giver and not being able to reproduce the results obtained by the "boss-log" group of the P5.

And again - facing the hurdles that they faced, it is quite possible that the solutions reached by the Indian establishment are not as elegant, efficient and magical as the solutions reached by others.

Of course there is a "bypass route" - the route taken by Xerox Khan and the route taken by a patriotic Chinese working in the US nuclear establishment who stole, for his country, the designs of one of the most sophisticated US warheads. That is a route open to us - but only karma will dictate whether it will bear fruit and we may have to resort to ancient practices like yagnas to get some nationalist to do for India what Chinese and Pakistani nationalists did for their nations. In the meantime we have to make do with what we have no?

[amit]

Too many people take a fractal recursive path and don the mindset of the colonizer/sanctions giver and become scathing critics of our own people for not following the path of the colonizer/sanctions giver and not being able to reproduce the results obtained by the "boss-log" group of the P5.

Very well said Doctor. IMVHO this para should be the first post on this thread. That would serve as a reminder for all folks who bemoan the fact that India does behave like the TFTA P5 and tell the world "in clear and unambigious terms" that India has giga bombs and would use them in slightest of provocation.

[amit]

You can read better about the genius of George Gamow in the book

John Snow ji welcome back! Was starting to miss you. I was very sad when you left in a huff during the legal-segal discussion a few days ago.

[svinayak]

That would serve as a reminder for all folks who bemoan the fact that India does behave like the TFTA P5 and tell the world "in clear and unambigious terms" that India has giga bombs and would use them in slightest of provocation.

It is about getting the final result from such major countries such as China. If china behaves with 20kt then even that is ok. What works is what India wants.

[Sanatanan]

Another site, which has the same sloika design, but also talks of the use of lasers for ignition:
Translation of Russian site

Very interesting to note some of the dimensions of the device:

Overall Dia of the main shell (excepting the cooling ring) --> about 5.5 millimetres
Overall height --> about 9.5 millimetres
Solid DT Fuel layer thickness --> 80 micrometres
He +H2 fill --> 1 milligram per cubic centimetre
Polyimide window thickness --> 1 micrometre
Be or Polymer capsule dia --> 2 millimetres

Is this some kind of a miniaturised ammunition for a nuclear rifle?

[hnair]

Is this some kind of a miniaturised ammunition for a nuclear rifle?

That probably is a sample inside a hohlraum, for testing in a laser ignition facility. It apparently mimics a fission primary's X-ray output, when lasers are focused into its cavity. Search for hohlraum. Also wiki has this picture of the tiny mustard seed

[amit]

If china behaves with 20kt then even that is ok. What works is what India wants.

I can agree with this totally. I also believe India's deterrence and nuclear muscle is a work in progress and because of that we need to keep our options to test in future intact at any cost. Hopefully that's what is happening.

There will come a time when India will regain its place in the Sun and be a major power both in military terms as well as economic terms. Unfortunately we are not there yet. And one cannot come without the other and both must progress simultaneously.

All this in IMVVHO, of course.

[Sanku]

Too many people take a fractal recursive path and don the mindset of the colonizer/sanctions giver and become scathing critics of our own people for not following the path of the colonizer/sanctions giver and not being able to reproduce the results obtained by the "boss-log" group of the P5.

Very well said Doctor. IMVHO this para should be the first post on this thread. That would serve as a reminder for all folks who bemoan the fact that India does behave like the TFTA P5 and tell the world "in clear and unambigious terms" that India has giga bombs and would use them in slightest of provocation.

Since I have said that sort of thing I believe I must interject.

I totally reject Shiv's claim as being applicable to me and I would say based on what I have seen of other "uber jingo" posts, I think that the others are also not thinking anything like what Shiv thinks they think.

The thinking is more like --- laws of Physics are invariant irrespective of the country, and so are mathematical theories like game theory -- and a lot of work suggests that Nuclear deterrence would be same for any country with a Nuclear adversary such as P5.

The above is clearly seen when the "Uber Indic kacchawalas" told Clinton that they were ready to lose 5x million to Pakistanis total population of X million if push comes to shove. So unless the RSS thinking and Rajputana tradition and everything just evaporated in One night, India showed in one moment that though we dont brag, we can be madder than than the maddest if it came to that.

In fact my piskological analysis says that the uber jingos are the uber Indics who have learnt from the Indic history that Indics are naturally coy about using overwhelming force and complete destruction of enemy (destruction of civilizations and genocides) as tool in war fighting where as they happen to be the FIRST desirable strategy for nearly everyone else (if they can implement it) and thus are very aware of this lacuane of Indians.

We are mad enough to die in droves when it comes to dying for the cause, but too good to do that to our enemy.

[Kanson]

Kanson it appears to me that PKI is assuming a particular design without knowing what design was tested. He is assigning a value to the yield of the primary when RC quoted 12 kt for primary and up to 45 kt for secondary.

PKI is saying

1) OK I accept BARC yield = 50 kt and I award 30 kt to primary and 20 kt to fusion
2) But if I take Santhanam's value of 30 kt I can only award 30 kt for primary and nothing for fusion

But RC had said on May 17th 1998 that the primary was 12 kt. This was picked up by Subba Rao and quoted ( in a link I have posted earlier)

So if PKI had taken 12 as Primary and takes Santhanam's 30 kt total value, you still get 12 kt primary and 18 kt of fusion plus spark plug (if any) Assuming spark plug was 10% of total yield you get fusion of about 13000 tons of TNT. It may be small for a fusion bomb - but it is still 40% of expected value which is not a fizzle if you look at Oppenheimer's definition of fizzle.

It seems, PKI got hold on to 20 kt figure for fusion. All his calculation are around that. So if you say the total yield is 40 kt, then we will come and say 20 kt for fusion and rest from fission and spark plug. If it 50 kt then 20 fusion, 30 rest. This is what he is doing from the beginning and attempted the same with K.Santhanam's assertion. But he never talked about how he arrived at the figure other than mentioning the amt of Li.

Note that Santhanam has diagnosed a fizzle by quoting fission bomb (S2) as 25 kt (instead of 15 kt) and rest of yield from S1. PKi is quoting 30 kt for primary instead of 12 kt in his diagnosis of fizzle.

The interesting part for me is how a close look at the yield values being quoted by both PKI and Santhanam actually go against the low values detected by the NPA/CTBT seismologists and are closer to the BARC values. But the nitpicking is the distribution of that yield among devices tested simultaneously.

ROTFL stuff

Now it all boils down to apportionment of total yield.

[shiv]

News picks from 1998 about the emerging sooperdooperpower:

http://www.nti.org/e_research/profiles/ ... _2893.html

27 May 1998
The European Union decides to work for a delay in consideration of loans
to India through the World Bank and other international financial
institutions.
—"EU Against Sanctions, but Will Delay Loans for India," Times of India
(Mumbai), 27 May 1998, <http://timesofindia.indiatimes.com/>.

28 May 1998
In the aftermath of Pakistan's nuclear tests, Prime Minister Atal Bihari
Vajpayee says India might reconsider its voluntary moratorium on nuclear
tests. Speaking to the press, Vajpayee states that "India is prepared to
meet any eventuality. We are committed to deterrence." He says that
Pakistan's clandestine preparations "forced" India "on the path of a
nuclear deterrent."

30 May 1998
Dr. S.S. Bhandare, chief economist for Tata Services Ltd., estimates the
effect of nuclear1related sanctions and increases in India's defense budg
between 85 billion and 100 billion rupees.
—"Budget '98: Sanctions and Defense Can Cost India Up To Rs 100 Billion,"
Rediff On The Net, 30 May 1998, <http://www.rediff.com>.

May 1998
Scientists from India's Tata Institute of Fundamental Research (TIFR) and
the Institute of Mathematical Sciences protest against India's nuclear
tests. The scientists argue that the money required for nuclear
weaponization can be better spent to modernize India's educational and
research facilities or fund developmental activities.
—T.S. Gopi Rethinaraj, "Indian Blasts Surprise the World, but Leave Fresh
Doubts," Jane's Intelligence Review (Coulsdon, Surrey), July 1998, p. 22.

May 1998
Senior Congress party leader Natwar Singh says the tests of May 11 and
13 "did not conform to the latest technology, as claimed." However, Singh
does not comment further citing national security reasons.

6 June 1998
The UN Security Council passes resolution 1172 (1998). The resolution
condemns the nuclear tests carried out by India and Pakistan and
endorses the Joint Communiqué issued by P15 Foreign Ministers on 4 June
1998. The resolution demands that India and Pakistan refrain from further
nuclear testing, urges both countries "to exercise maximum restraint and
to avoid threatening military movements, cross1border violations, or other
provocations in order to prevent an aggravation of the situation." It calls
on India and Pakistan "immediately to stop their nuclear development
programmes, to refrain from weaponization or from the deployment of
nuclear weapons, to cease development of ballistic missiles capable of
delivering nuclear weapons and any further production of fissile material
for nuclear weapons, to confirm their policies not to export equipment,....

12 June 1998
The G18 countries meet in London "to consider the serious global
challenge posed by the nuclear tests carried out by India and Pakistan."
The Joint Communiqué issued after the meeting urges India and Pakistan
"to stop all further nuclear tests and adhere to the CTBT [Comprehensive
Test Ban Treaty] immediately and unconditionally, thereby facilitating its
early entry into force; to refrain from weaponization or deployment of
nuclear weapons and from the deployment and testing of missiles capable
of delivering nuclear weapons, and enter into firm commitments not to
weaponize or deploy nuclear weapons or missiles; to refrain from any...

October1November 1998
Israel succumbs to US pressure and orders Israeli aerospace and defense
firms to suspend pending defense deals to India. On 30 October 1998, an
Israeli defense ministry official makes a statement saying that this is "a
temporary, voluntary freeze that may or may not be adhered to
depending on the circumstances." The official emphasizes the effort to

18 November 1998
The former chairman of the Atomic Energy Regulatory Board (AERB), Dr.
A. Gopalakrishnan refutes the claims of the Department of Atomic Energy
(DAE) and the Defense Research and Development Organization (DRDO)
that enough data have been collected for computer simulation and
sub1critical tests and that India can proceed to sign the Comprehensive
Test Ban Treaty (CTBT). Gopalakrishnan says India is yet to validate its
weapon designs and computer codes. Gopalakrishnan refers to the
seismological estimates of the yield of the May 11 tests with the mean
value of 12.5kt and standard deviation of 3kt that contradicts the
cumulative yield announced by DRDO and DAE on 17 May (about 56kt).
He discards as baseless the premise that the discrepancy arises due to
inaccurate deduction of the yields from the multiple explosions. According
to Dr. Gopalakrishnan, "if scientific data collection was the main objective"
of May 1998 tests, a number of single1explosion tests should have been
carried out since multiple simultaneous tests serve the purpose of
studying the "synergetic effects on targets" and exploring "specific
applications of multiple explosions" and not the verification of weapon
designs.
—A. Gopalakrishnan, "How Credible is Our Deterrence," Hindu (Chennai), 18
November 1998, <http://www.hinduonline.com>.

26 November 1998
Indian government sources indicate that India intends to sign the
Comprehensive Test Ban Treaty (CTBT) by September 1999 after taking
parliament into confidence. The sources also suggest that the issue of
"nuclear restraint" has been the major stumbling block in Indo1US
negotiations with the United States, insisting that India cap its nuclear
and missile capabilities. As far as fissile material cut off is concerned, India
rejects an immediate moratorium on fissile material production. However,
India will consider the issue of fissile material cut1off "in the course of
multilateral negotiations" in Geneva when India will get "some idea on the
exact position of the US on the FMCT [Fissile Material Cut1Off Treaty]
issue."

23 December 1998
India's Minister of State for External Affairs, Ms. Vasundhara Raje tells
parliament that Indian scientists have clearly established the total yields of
the devices tested on 11 May 1998 and the yields are in conformity with
the announced values. She says that four different methods of analysis
were used to estimate the yield from the nuclear tests. The methods,
which included global seismic data evaluation and close1in acceleration
measurement, have confirmed that a fission device of 15kt and a
thermonuclear device of 45kt were tested on 11 May [DAE and DRDO
official statement of 17 May indicated 12kt and 43kt]. Ms. Raje says that
drilling operations at the site of the thermonuclear test are under way and
similar operations will be undertaken at the site of the fission blast. The
analysis obtained from samples from these operations thus far "conforms
to the predicted behavior of the tested devices."
—"India Did Detonate Thermonuclear Device," Hindu (Chennai), 24 December
1998, <http://www.hinduonline.com>.

Mid-January 1999
China publicly questions the legitimacy of the US-India nuclear dialogue. Acording to the Director-General of the Department of Arms Control and Disarmament in China's Ministry of Foreign Affairs, Ambassador Sha Zukang, negotiating with India the issues of "nuclear deterrence capability" violates the UN Security Council resolution 1172. Sha also says it is very "unhelpful to publicly support India's permanent membership in the UN Security Council soon after its nuclear tests."
—C. Raja Mohan, "China Slams India's Nuclear Talks," Hindu (Chennai), 18 January 1999, <http://www.hinduonline.com>.
14 January 1998
The United States rejects permission for eight senior US physicists from the Fermi National Accelerator Lab and the Argon National Lab to participate in an international symposium on particle physics at the Tata Institute of Fundamental Research (TIFR) in Mumbai. TIFR is on the list of sanctioned entities issued in November 1998. However, 25 US scientists from private institutions and universities attend the symposium.
—Pallava Bagla, "Washington Blocks 8 US Scientists from TIFR Physics Seminar," Indian Express (Mumbai), 15 January 1999, <http://www.expressindia.com>.

Mid-January 1999
Atomic Energy Commission (AEC) Chairman Dr. R. Chidambaram says that India has an adequate scientific database "for designing...a credible minimum deterrent." However, Chidambaram adds, should the government change the 'minimum' parameters of the proposed deterrent in terms of yields and performance criteria, then tests will become necessary.
—Cited in, Bharat Karnad, "Hesitant Nuclear Realpolitik: 1966-To Date," Nuclear Weapons and Indian Security: The Realist Foundations of Strategy (New Delhi: Macmillan, 2002), p. 427.

3 February 1999
A senior Chinese diplomat says China is not going to change its position on the nuclear issue in South Asia and will insist that India sign the Comprehensive Test Ban Treaty (CTBT) unconditionally. The Hindu reports that the Chinese government is "concerned" with the US moves to recognize India's demands for a minimum nuclear deterrent. Sha Zukang, China's Director-General of the Department of Arms Control under the Chinese Ministry of Foreign Affairs says, "it is a direct violation of the UN Security Council resolution 1172 to negotiate, or even to discuss with India, the so-called minimum deterrence capability."
—"China concerned over US Move on Indian N-Tests," Hindu (Chennai), 4 February 1999, <http://www.hinduonline.com>.

4 Feb 1999
Atomic Energy Commission (AEC) Chairman Dr. R. Chidambaram addresses the Association of Indian Science Writers. He asserts that a "post-shot" analysis of the Pokhran II tests had confirmed that the May 1998 tests yielded about 60 kilotons as had been initially estimated by the AEC. Chidambaram says the scientists at the Bhabha Atomic Research Center (BARC) had used four methods to calculate the yields. These methods included the measurement of various types of shock waves and comparison of "some of the data from other seismic centers all over the world." Chidambaram points out that India had tested a "fusion-fission-fusion" device on 11 May 1998. He says a boosted fission device was a part of this design and there was no need to test it separately. According to Chidambaram, India was working on powerful lasers for "inertial confinement to produce fusion energy and uranium enrichment." He says India has developed the lasers although it does "not have the full energy yet." Chidambaram notes that Pokhran tests were "perfect" since Indian scientists had mastered "optimum emplacement of the device to ensure that over-digging or radioactive spillover was avoided."
—"Further Nuclear Tests Unnecessary," Hindu (Chennai), 4 February 1999, <http://www.hinduonline.com>.

[Kanson]

Kanson I mentioned the fact that some fusion has occurred with conventional explosive merely to point out that it appears (to me) that if you compress and heat Tritium in a conventional bomb a few atoms here and there may actually fuse - but to get a bang the conditions have to be relatively precise.

But even "precise conditions" for fusion might mean a variation of a small amount in the region of a few million deg C this way and that way and a few dozen MPa pressure this way and that within a few nanoseconds here and there - with a range of fusion being obtained within those limits.

I we take the pressure from Chemical explosives as 1 then pressure created by N explosion can easily be 2 or 3 times greater than that. And second we need to think abt the temperature for the fusion to occur. So it cant be termed as a "small variation" this way or other, i believe.

If you get fusion within that range you have achieved one point out of several thousand points in that range. Unless I am mistaken the way to get more info is either to do several thousand tests for several thousand data points or use simulation for EOS based on a few known data points. This is way out of my area of expertise and I am wondering if anyone can throw light.

I think this can be explained easily. For to derive EOS, theoretical calculations and experimental data compliments each other. You can read theoretical calcualtions as simulation and experimental data as validations to say the simulation is carried in the right way.

If one resorts only to experimental data collection without any effort on to theoretical side, its akin to blind man groping the elephant. Any body in curve fitting business will agree to that. If any nuclear program is based only on experimental data then for every design it needs to conducts several tests to bring a new weaponised bomb.

On the other side, if a side is good in theoretical disposition and can predict the various interactions and phenomena happening during the N explosion then it needs few data from experiments or tests and it is just for validation.

What happens over the years due to so much of studies on N physics is more & more understanding on the parameters that cannot be calculated theoretically and with time the number of unknown parameters comes down more so with advancement in computer power. This is how RC call our weapon as 1998 vintage. If you take a look at SSP of US, they are exactly fixing the unkown parameters that we discussed here. So, If your theory is strong no. of iterations done on computer too comes down.

Next question is so how good is their theoretical prowess?
On their theoretical prowess, one thing that was surely demonstated during POK-II was sub-kt devices. You might be aware of the spat of CTBT with Chinese and their reluctance with less than 1 kt yield etc etc. So we proved to the world concerned or to the people who are knowledgable on how good we are.

Second thing available to public is the publication from BARC. There are several good papers and RC has some good publications on hydrogen-bonding. That was well received internationally i guess. Further, BARC has published papers in current science showing how their experiemntal data matches to their theoretical or simulation derived data points.

So to cut the discussion shot, if one is good at arriving EOS and other calculations theoretically he may need only few tests. Even the critics like Santhanam and PKI never talked about carrying serveral dozens of tests on TN. Santhanam went on record asking for 1 or 2 more tests only. That will probably hit the final nail on the coffin asking for dozens and hundereds of tests.

[shiv]

Thanks Kanson.

The interesting things about all these news items is the number and identities of people who have expressed some doubt about the S1 test. But apart from Iyengar and to an extent Santhanam - nobody has actually brought any data to the table and have tended to quote a limited set of seismo reports (not even all of them)

The group are:

Homi Sethna
PK Iyengar
K.Santhanam
A.Gopalakrishann
Subba Rao (? not a real insider?)

I am not adding Bharat Karnad here because he is an "outsider" of sorts not actually having worked in the labyrinths of the establishment.

I just wonder if there is a clear rivalry between the team that got a chance to test their designs versus the people who did not. Ramanna is the exception.

Another point to note is that Chidambaram himself says that the future of weapons in India is closely linked with the "minimum" in CMD. If that changes testing will be needed.

[SaiK]

one thing is fo shizzle.. we can't argue on the basis of "minimum" of the minimums.., when the strategic interests are best served by derated values on the yields.., and the maximum benefits obtained as a result of productionizing on these derated values.

it feels safer to say i have designed a 200KT weapon, by testing a 350KT weapon., keeping the technology and science behind these strategic pisselgics.

[shiv]

it feels safer to say i have designed a 200KT weapon, by testing a 350KT weapon., keeping the technology and science behind these strategic pisselgics.

But if you are the scientist and are asked to secretly prepare a test in an existing shaft that can't take 100 kt how do you plan a test? Assuming throwing up your hands and refusing to test is not an option?

I asked the same question in a questionnaire many pages ago. Nobody seemed to have any answers.

[samuel]

Why couldn't they dig more tunnels in 20 years if there was some kind of systematic plan to develop nuclear weapons and deterrent? And why only Pokhran, are there no other separated diggable sites in India where they could do tests if separation in time was not possible?

If someone came to me and said do it with the constraints you've mentioned, I'll tell them clearly it won't translate to much in reality and, if they insist, I'll understand it's a show and give them that to keep my job and then find a way to avoid this problem in the future, possibly by moving out, or waiting until I can talk or act. I would come out even more strongly if someone on that basis was thinking of signing away testing all together.

JMT
S

[SaiK]

If I were in RC position (i am not a scientist btw), I would have asked for a shaft that needs 200 meters or 300 meters to do whatever tonnage we would like to do... YES its a matter of pride, and these kind of events don't come everyday, and every scientists knows that.. its hard to get a time like ABV saying, go ahead and do it!!.. man what a privelege is that, and plus the time is critical to get everything done for the future.

I can't say, well given these conditions, we have done our best.. yadi yada.. thats lame. I am with Samuel, and would have asked pokhran be shifted to lakshwadeep or guntur under some already available 300 meters of hills and granite layers, or some rayalseema place.

[svinayak]

If china behaves with 20kt then even that is ok. What works is what India wants.

I can agree with this totally. I also believe India's deterrence and nuclear muscle is a work in progress and because of that we need to keep our options to test in future intact at any cost. Hopefully that's what is happening.

Reality is very tough and India may not have time to react. The question is what does china react to-a 20kt or a 300kt

[Amber G.]

Shiv: Minor point - I did not see B4 (sorry if it was answered etc)

5) As regards Tritium it is an "either-or" situation with Plutonium. That means that in order to create Tritium in you reactor you have to stop creating Plutonium.

For Inidia's PHWR case , If I am not wrong (correct me if I am), T comes out of water (instead of core) so it is a by product and it is not either-or situation.

Added later: I see Vina has already commented.. anyway ... leaving the post as it is.

[Gagan]

Guntur or Lakshadweep are out as far as N test sites are concerned.
You need an area where is no human habitation / crops cultivation for atleast 20-30 kms. There are very few places within India where this is possible. Laddakh is the only one that I can think of.

Barren Island , Narcondum island in the A&N islands are the other possible. Otherwise, except in the test range around Khetolai, there is almost no place in india where there is no village or cultivation nearby. India is filled with villages every few kilometers or so.

The lakshadweep islands are more or less sandbanks some of them, a N explosion below one will cause it to vanish into the ocean. Add to this the complication of maintaining a shaft that'll fill with sea water immediately as its dug.

[tejas]

Guntur is too near Tenali ( my birthplace) so scratch it off your list.

[Gagan]

Very nice paragraph on wiki on tritium

Tritium is widely used in nuclear weapons for boosting a fission bomb or the fission primary of a thermonuclear weapon. Before detonation, a few grams of tritium-deuterium gas are injected into the hollow "pit" of fissile plutonium or uranium. The early stages of the fission chain reaction supply enough heat and compression to start DT fusion, then both fission and fusion proceed in parallel, the fission assisting the fusion by continuing heating and compression, and the fusion assisting the fission with highly energetic (14.1 MeV) neutrons. As the fission fuel depletes and also explodes outward, it falls below the density needed to stay critical by itself, but the fusion neutrons make the fission process progress faster and continue longer than it would without boosting. Increased yield comes overwhelmingly from the increase in fission; the energy released by the fusion itself is much smaller because the amount of fusion fuel is much smaller.

Besides increased yield (for the same amount of fission fuel with vs. without boosting) and the possibility of variable yield (by varying the amount of fusion fuel), possibly even more important advantages are allowing the weapon (or primary of a weapon) to have a smaller amount of fissile material (eliminating the risk of predetonation by nearby nuclear explosions) and more relaxed requirements for implosion, allowing a smaller implosion system.

Because the tritium in the warhead is continuously decaying, it is necessary to replenish it periodically. The estimated quantity needed is 4 grams per warhead.[3] To maintain constant inventory, 0.22 grams per warhead per year must be produced.

As tritium quickly decays and is difficult to contain, the much larger secondary charge of a thermonuclear weapon instead uses lithium deuteride as its fusion fuel; during detonation, neutrons split lithium-6 into helium-4 and tritium; the tritium then fuses with deuterium, producing more neutrons. As this process requires a higher temperature for ignition, and produces fewer and less energetic neutrons (only D-D fusion and 7Li splitting are net neutron producers), LiD is not used for boosting, only for secondaries.

[NRao]

For what it is worth, I think tunnel digging has to be authorized by the PM. The '98 tunnels were, over a period of time, authorized by 2-3 PMs in the past, including one by IG.

[shiv]

Why couldn't they dig more tunnels in 20 years if there was some kind of systematic plan to develop nuclear weapons and deterrent? And why only Pokhran, are there no other separated diggable sites in India where they could do tests if separation in time was not possible?

If someone came to me and said do it with the constraints you've mentioned, I'll tell them clearly it won't translate to much in reality and, if they insist, I'll understand it's a show and give them that to keep my job and then find a way to avoid this problem in the future, possibly by moving out, or waiting until I can talk or act. I would come out even more strongly if someone on that basis was thinking of signing away testing all together.

JMT
S

Samuel the digging of tunnels is a political decision as is the allowing of testing without making tunnels too much deeper.

I believe those tunnels were initially dug in the 1980s when India had built up a number of 25 kt fission bomb cores (as per one of my links above). The idea of using them for a test cropped up under the Narasimha Rao (PVNR) government in 1995 or so - at which time the Americans detected preparations for a test.

What I have never understood is the global balance of power equations that made PVNR back out of testing. Why did he not have the "guts" to go ahead with the testing? It is likely that there were pressures on him that far outweighed (in his mind) the need to test. I would be grateful if any forum member can throw light on why the PVNR government would have felt such pressure in 1995 which the ABV government seemed willing to face, albeit by preparing to test secretly.

Clearly ABV seemed to calculate that if the test preparations could be kept secret, any tests would be a fait accompli, and that any sanctions/pressure that India faced would be after the tests and after India had declared itself a nuclear weapon power - giving itself wiggle room to say "We have demonstrated nuclear bombs so you cannot negotiate with us like you negotiate with non nuclear states". ABV was perfectly right in his gamble - but and here's the problem..why on earth were both PVNR and ABV so unhappy about _detection_of_preparations_ for testing? PVNR was forced to back out and ABV managed to weasel the tests through - to his credit.

It is obvious to me that prior to 1998 India was looked upon as a non nuclear weapons state. What pressures could have been brought on India had preparations for testing been detected? Pressures that had already made PVNR back out?

I believe an understanding of these factors is crucial to understanding why the 1998 tests were conducted in existing tunnels that were not designed even for high fractions of megatons.

[Sanatanan]

That probably is a sample inside a hohlraum, for testing in a laser ignition facility. It apparently mimics a fission primary's X-ray output, when lasers are focused into its cavity. Search for hohlraum. Also wiki has this picture of the tiny mustard seed

Thank you for the useful tip. I shall look it up.

[shiv]

Additional thoughts - as a scientist - if faced with the need to test some (any) bomb device in existing tunnels of ~200 meters it should not have been too difficult given India's existing bomb capability. Even the testing of 2-3 existing fission devices would have sufficed to achieve Vajpayee's political aims of putting India in a group of nations with demonstrated nuclear bombs.

But Kakodkar is on record as saying that 11 or 12 different designs were tested in those 5 tests.
Let me not start an argument abut whether they worked or not but some of those "designs" were revealed at least in the form of isharas. One of the designs may have been the existing fission bomb itself; another the testing of reactor grade PU; a third the use of boosted fission and a fourth would have been the two state thermonuclear design. Perhaps there were other things like explosive lenses and material tested. In addition PK Iyengar - who was by then out of the core design team loop also spoke of more that one design of thermonuclear bombs.

The impression I get is that the nuclear establishment has some leeway to think about and plan a few new nuclear bomb designs, but testing them becomes a political hurdle. So it appears that the scientific establishment had more plans than the political establishment was willing to permit. It was the political goals that were limited apart from being restricted.

As an aside, Santhanam was responsible for the field preparations in Pokhran. I suspect he would have been consulted if there was a need to make tunnels much deeper. There is some reference to the tunnels having been modified a bit and perhaps made somewhat deeper - maybe in Chengappa's WoP, but obviously the device that went into the ground as "S1" was not designed to yield more than 45 kt as per everyone including Santhanam himself.

[Umrao Das]

Digging holes is always a political decision and they are quite adept at that. The depth to which they go digging is a factor of personality of the leadership.

With the Fussion test we dug overselves into the biggest hole wholesale.

[Umrao Das]

A usable system consists of sub systems. A design could be considered to be new, modified, upgraded, improved etc without changing the functional capbilities or the capacity to deliver certain outcomes.

There fore a bakers dozen changes need not necessarily increase the capacity. It could be such that the "new designs" could be to reduce the size, reduce the cost, reduce production operations or sequence, material substitution etc.

If I use self tapping screws instead of a nut and bolt, it could be termed as new design, if I could further improve by snap (snug) fit it with out getting screwed, it could termed a revolutionary design too...

[Gagan]

This means that India may never be able to do further tests on the sly.
Unless the corps of engineers has already dug really deep shafts after 1998 and kept them ready in anticipation of a test of a big one. They did that all these years. I read in some videshi magazine where they commented that the Indian army corps of engineers has been upto something very unusual to fool the sat surveillence. They would dig holes at random and then fill them up all throughout the year in and around the test area.

If it is possible to do a big test deep enough without any surface disturbance ie no retrac or crater, does this also mean that seismic damage to the nearby 13 odd villages in a 10Km radius of Khetolai can be controlled similarly?

I guess perhaps not. Meaning that the pokharan test range is NOT going to be the place where a megaton yield TN will be tested.

[Umrao Das]

What is this obsession with Mega Tons?
We have mega millions to feed, mega million babes to deliver, lets get busy on that front.

[arnab]

What is this obsession with Mega Tons?
We have mega millions to feed, mega million babes to deliver, lets get busy on that front.

Yes - unfortunately not every family in India has sugar daddies like the late-lamented JS ji who has gone hither and yon providing educational benefits / income support benfits and asset acquisition for his family (and has even found time to fix his own Lexus). A majority of Indians still have to depend on the 'kindness' of GOI (such as it is)

[shiv]

What is this obsession with Mega Tons?
We have mega millions to feed, mega million babes to deliver, lets get busy on that front.

OT post for this thread. I have reported it as an OT post, but my reply is in the correct thread
http://forums.bharat-rakshak.com/viewto ... 15#p756215

[enqyoob]

So after 3,700,253,343 words, the Fyoozzle Fizzle crowd remains "fizzled", to put it mildly. Can't shake the Khetolai Certainty. Now it's down to wishful thinking, as in "I would have dug 200 mile deep tunnels in Guntur, Himachal Pradesh, and 200 other tunnels because it's as good a way of wasting time as any".

Maybe there never was any intention to test anything larger, because the strategic thinking is sharp. Focus on the delivery systems, which is really useful technology and conveys a far more effective deterrent, instead of wasting resources on completely useless Big Bums.

Will check back in a week or so. And another 2000 posts downstream.

[shiv]

This means that India may never be able to do further tests on the sly.
Unless the corps of engineers has already dug really deep shafts after 1998 and kept them ready in anticipation of a test of a big one. They did that all these years. I read in some videshi magazine where they commented that the Indian army corps of engineers has been upto something very unusual to fool the sat surveillence. They would dig holes at random and then fill them up all throughout the year in and around the test area.

If it is possible to do a big test deep enough without any surface disturbance ie no retrac or crater, does this also mean that seismic damage to the nearby 13 odd villages in a 10Km radius of Khetolai can be controlled similarly?

I guess perhaps not. Meaning that the pokharan test range is NOT going to be the place where a megaton yield TN will be tested.

Gagan forget the place or ability to dig. Two Indian PMs have clearly displayed fear of being discovered if shafts are dug. Why is there such a fear?

[vera_k]

Two Indian PMs have clearly displayed fear of being discovered if shafts are dug. Why is there such a fear?

India lacks reliable delivery systems. Without delivery systems that can reach around the globe, there is always the possiblity that a major power will make pre-emptive strikes to disarm India. Benazir asked for such pre-emptive strikes after the 1998 tests.

[Gagan]

There has to be a personal aspect to it. The big powers would threaten to pull out some of the many skeletons in the cupboard of the netas. It is this "log kya kahengey" that forces tehm to capitulate.

PVNR's son was implicated in that urea import scandal, but that was when he was near the end of his term.

As an example of how personal pressures work, see how the US negotiates with the pakistanis. One general goes in and does some good old general to general talk with the CMLA / COAS there. There is an emphasis on who within the US Gov circles knows the high up ministers within a country to get some leverage into. Just the way everyday politics works between any two nations in the world.

There has to be an aspect of upsetting the numerous loans and projects that India has with so many nations. Projects worth say $ 10-20 Billion going on with numerous companies, would be stopped if the US & other countries applied sanctions.

So I would say, both personal and national pressures come into play.

[Gagan]

In PVNR's case GoI was actively seeking foreign investment into India, mostly from the US. In those days, with the economy being zilch, any suggestion of sanctions would have lead to real disaster. PVNR had no choice. The images of india back in 1974 sanctions must have been fresh in the minds of the leaders then.

Which brings me to the subject. Do you all think that PVNR would have really gone ahead with the tests? Or did he use this as a bargaining tool to get something from the US? The sanctions would have crippled India if he had gone ahead with testing, I am sure he was well aware of this.

[vera_k]

Per K Subramanyam's account, Rao's pullback was because of a lack of consensus. In that case, it truly seems like a case of the enemy within - not much different from today. If this is true, then Vajpayee then would have had to prepare secretly more to prevent the breakdown of consensus within India and less from any desire to hide the preparations from foreigners.

I asked him why he called off the nuclear test of December 1995. He said there was no consensus on the test. There were divisions not only among the economists and administrators but also among the scientists themselves. He felt that he would conduct the test if he came back to office.

http://www.idsa.in/publications/strateg ... %20Sub.pdf

[enqyoob]

vera: In some internet forum I saw this deep calculation of "yield" vs. CEP. He was arguing that a 17KT nuke with a CEP of a few meters, is far more potent a deterrent than a 450KT with a fairly large CEP. This is the sort of minimalist thinking that would appeal (rightly) to GOI thinking. It is the True Indian approach. I tend to agree that putting money into extracting lots of enriched fissile material and building gadgets that are so much trouble to test.

By staying away from testing nukes, India kept the freedom to test missiles, and that has been carried to high levels of refinement. The ABM and BrahMOS demos were the clinchers. If that kind of response time and that kind of accuracy can be done by DOOs, then the point is proven - India can put nukes through the ventilator shaft of the Led Rips Massage Palroul and C^3 Centel too.

As my 4th cousin has pointed out many times, the times have changed. Large long-range ballistic missiles are a terrible investment today.

[vera_k]

Large long-range ballistic missiles are a terrible investment today.

Sure, but can you say the same for small long-range ballistic missiles? Those haven't become redundant.

[shiv]

Ok lots of interesting and plausible explanations regarding why PMs might not allow open digging of nuclear test shafts, and serious digging can't be hidden from satellites.

The bearing this political hurdle has on nuclear tests is that if you have only shallow pits you can test only fizzle yield devices. Even 100% success in Pokhran would have been less than 75 kilotons.

The point here is that if someone thinks that deterrence is not possible without publicly demonstrating a minimum of 150 kt then it means that the 1998 tests added nothing to deterrence that was not present before 1998.

Note that all suggestions of "improvements since 1998" and "simulation" and "ability to design" and "scaling" can easily be dismissed as false in the absence of clear, unambiguous proof that a design of several hundred kilotons was tested. Taking a leaf from SaiK's post a minimum of 350 kt should have been tested, if not the desired megabooms (Both Karnad and Santhanam talk of yields in megatons being required to deter a foe with megaton bombs)

But such large tests were never possible given the constraints. Therefore it is possible to conclude that at least in some people's minds

1) Deterrence does not exist vis a vis China
2) The 1998 tests made no difference in terms of value addition to deterrence.