Two ways this Outlook article by PKI interests me. It confirms that there is no blue or whatever panel formed still to do the peer review. Almost all of the points rasied here are hammered already by PKI et al though DAE gave an explanation for all the doubts raised. That suggests is this excerise is just a measure to keep the pot simmering and what happened to K.Santhanam ? After the RC/AK interview there was no fresh bomb blast from him. Or these are preludes to coming drama.
Another thing suprised me is PKI chose to explain his rationale for the fusion burn. Just few days before me and Shiv were discussing that here
and slightly mocked him as he always talks about 20kt for fusion.
That article in question is expressbuzz
dated 02 Sep 2009
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.
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.
If it is 30 kt , he comes to the understanding that there is no fusion.
In this Outlook, he says...
Dr R. Chidambaram, and the chairman of the Atomic Energy Commission (AEC), Dr Anil Kakodkar, sought to address the ‘doubts’ raised by Dr Santhanam about the efficacy of the thermonuclear (TN) test. Were their clarifications adequate?
Dr Santhanam, who was in charge of the measurements at the site, claims that the S2 (shaft-2) site in which the fission device was detonated gave a yield of 25 kt and the TN device in S1 gave much less. International seismologists, with rich experience in operating a sophisticated seismic array, all converge on a total yield not greater than 30 kt.
Taking the Pokhran-I yield as close to 8 kt, as I know it as its project head, the total yield of Pokhran-II works to only 36 kt, leaving only 24 kt for the TN device (since the DAE claims 12 kt for the fission test). This is closer to the international evaluation, though slightly higher.
So, part of the TN yield would have come from the boosted-fission trigger and part from the fusion burn. In 2000, I had liberally estimated this ratio to be 1:1. This was later agreed to by Dr S.K. Sikka as well, who was the scientific head of the BARC design team. With this number for the thermonuclear burn—12 kt (the other 12 kt coming from the fission trigger in that 1:1 ratio)—I have calculated that only around 250 gm of the LiD (Lithium-6 Deuteride) fusion material would have burnt. I know for sure that the BARC has the means to make highly enriched Li-6 from 1970. This amount of LiD translates to a core size of around 4 cm in radius, too small for a realistic size of an LiD core. It’s more likely that around 2 kg of LiD (8 cm radius) was used, in which case the burn efficiency would be around 10 per cent. The core’s shape could have been different from spherical.
From the 20 kt figure he moved to 1:1 ratio. He is dragging Sikka into this, further.
From his article published in 2000,
The crucial question is not what the total yield of the device was, but what was the ratio of fission energy to fusion energy? Clearly, for a given total yield, the greater the fraction of the fusion energy, the more efficient is your thermonuclear device. In my opinion, that ratio musts have been around 1:1, and no one has so far, to my knowledge either publicly or privately, disputed that number. Therefore, by my estimate, the fusion yield could not have been more than 20 kt. Further, it seems likely that a fission `spark-plug’ was used at the centre of the fusion core, in which case the actual fusion yield would have been even less.
Sticking to the larger number of a 20 kt fusion yield, one can easily calculate that the amount of LiD fusion material needed would be only around 400 grams or around 500 cc. This is a very small size for the fusion core, and the actual core used must certainly have been much larger. This suggests that the fusion core burnt only partially, perhaps less than 10 per cent. This can easily be checked; if the burn was only partial, there should have been a lot of tritium produced, which should have been detected after the explosions.
If anyone publicly or privately doesnt disagrees means makes him automatically agreeing to that ? I dont know.
So far he is sticking to 1:1 ratio and patial burn percentage as 10%. So what makes him to liberally estimate the ratio to be 1:1 and the total material as 2 kg. He talks about the size of the fusion core radius as 8 cm. In 2000 he is talking about 4kg fusion material. Are these based on his previous designs while he was at helm ?
By BARC estimation the ratio is around 1:2. In the famous US warheads W87/88 the ratio is 1:2 (100kt:200kt). Not without any reason RC proclaimed that ours is based on 1998 vintage.
Lot of tritium is supposed to get produced as the efficiency of fusion burn is around 50% only. Remaining fuel automatically changes to tritium in the process.
Shiv wrote:I wonder if PKI has some serious concerns about the possibility that politics is interfering with India's ability to have future ready weapons - when every advanced country is moving towards small (maybe 0.1kt to 2 kt) fusion weapons.
Supprising Shiv ji. Any pointers towards this ? Only thing that comes to my mind is CTBT.