Showcase of technological leap by Indian nuclear establishment

The second kind, termed as the low-yield device, has a much wider military utility than the othertwo types. With this, a boosted fission device, India could be making nuclear weapons in an as wide a spectrum as artillery shells, specialised demolition devices for military engineers and special forces, submarine launched ballistic missiles, and more significantly for precision guided munitions for use in combat aircraft. These are based on a higher level of warhead design capability, said the specialists.

It is with the third category, however, that India is really in the big league of nuclear weapons technology. The thermo-nuclear device is based on a fusion nuclear chain, and is also called a hydrogen bomb. And this is the route to be taken for any country wanting to deliver intermediate range or intercontinental ballistic missiles. This, said the specialists, is the basis for a warhead on the Agni and missile and its variants that will follow. The logic of naming the missile Agni now makes sense since a thermo-nuclear explosion produces a fire, remarked a military nuclear specialist.

The finalprocess of inducting nuclear weapons is still a while away, with the data transmitted by these tests being translated into the design of warheads a fairly complicated process. But it is the pool of this data will be continuously used on the Param supercomputer family in order to achieve greater finesse in the design of nuclear warheads or even the low-yield devices. This, said the specialists, is where the sub-critical experiments through computer simulation come into play.

OUR CORRESPONDENT ADDS FROM WASHINGTON: By conducting three back-to-back tests, the Indian nuclear and security establishment were seeking to validate and improve their existing weapons designs, achieve miniaturisation of warheads for ballistic missiles, and prove their ability to make bigger and more devastating hydrogen bombs, top American nuclear scientists and security experts said.

Deciphering the cryptic announcement made by Prime Minister Atal Behari Vajpayee, experts here say the fission test was essentially a repeat ofthe first Pokharan test conducted almost 24 years ago to the day May 18,1974. It would suggest Indian scientists were trying to authenticate the weapons design they had and certainly get more data to improve the design. Previous US intelligence reports about the 1974 test and its aftermath speak of the basic Indian nuclear weapons design being too heavy and clunky.

By announcing that they had exploded a low yield nuclear device which is the same as a fission test, the Indian establishment appears to be suggesting that they have succeeded in miniaturising a nuclear weapon to fit it as a warhead on a missile like say the Prithvi, scientists here say.

They could also have tested a trigger for a thermonuclear weapon. It8217;s very hard to make the yield smaller. It implies significant advances, David Albright, a top nuclear expert with the Institute of Science and International Security told The Indian Express.

Albright, who has studied the Indian nuclear weapons program for years, also said thelow yield test might have involved highly enriched uranium in place of plutonium, which is the usual fuel for fission tests.

The thermonuclear test 8212; third among the tests announced 8212; means India has joined the quot;elitequot; club of countries with H-bomb capability. The Indian test, experts here say, might have involved a two-stage weapon using tritium to boost the yield

quot;It8217;s a souped up nuclear device. It would put India on par with other advanced nuclear weapons nations and be seen as a matter of prestige for Indian scientists,quot; said Professor Stephen Cohen, a South Asian expert, who has also followed all the arms control issues in the region.

While countries can have fission-based atomic weapons without testing it, a test would be an absolute necessity to make a hydrogen bomb, scientists say. quot;This whole exercise is quite likely an exercise to showcase India8217;s thermonuclear capability. It is the one test that India needed to do to show they have a Hydrogen Bomb,quot; according to Paul Leventha, who workswith the Nuclear Control Institute in Washington.

Today8217;s test explosions have demonstrated India8217;s capability to actually deploy nuclear technology for military use in three categories:

A repeat of the first Pokhran test, based on an uncontrolled chain reaction using weapons-grade plutonium. No different, except in the magnitude of the blast, from those which destroyed Hiroshima and Nagasaki. The simplest technology to deploy against cities and large military installations.

Yield is a few kilotons. Small enough to be put into a shell casing or to be carried by an infantryman. Intended for tactical objectives 8212; dams, bridges, military targets 8212; where mass destruction is not desirable. Traditionally called a Tactical Nuclear Weapon.

A two-phase explosion which uses a small, controlled fission reaction to compress the actual feedstock 8212; either the hydrogen isotopes deuterium and tritium or lithium-6deuteride 8212; to critical mass. The flash temperature of the explosion can reach 100 million degrees Kelvin. The temperature of the sun8217;s core is 14 million degrees Kelvin. Ideal for deployment where the idea is to ensure maximum destruction. Popularly known as the hydrogen bomb.