Question: Rajagopala Chidambaram know for his role in India's nuclear weapons program is scientist who has specialized knowledge in the field of what?

Context paragraphs:
Nuclear program of Saudi Arabia: Saudi Arabia is not known to have a nuclear weapons program.  From an official and public standpoint, Saudi Arabia has been an opponent of nuclear weapons in the Middle East, having signed the Treaty on the Non-Proliferation of Nuclear Weapons, and is a member of the coalition of countries demanding a Nuclear-weapon-free zone in the Middle East.  Studies of nuclear proliferation have not identified Saudi Arabia as a country of concern.

Timeline of nuclear weapons development: This timeline of nuclear weapons development is a chronological catalog of the evolution of nuclear weapons rooting from the development of the science surrounding nuclear fission and nuclear fusion.  In addition to the scientific advancements, this timeline also includes several political events relating to the development of nuclear weapons.  The availability of intelligence on recent advancements in nuclear weapons of several major countries (such as United States and the Soviet Union) is limited because of the classification of technical knowledge of nuclear weapons development.

S. K. Sikka: Satinder Kumar Sikka is an Indian nuclear condensed matter physicist, crystallographer and a former Scientific Secretary to the Principal Scientific Advisor of the Government of India.  He is known to have played a crucial role, along with Raja Ramanna, Rajagopala Chidambaram and Basanti Dulal Nagchaudhuri, in the design and development of a Hydrogen Bomb by India, which was tested at the Pokhran Test Range in May 1998, under the code name, Operation Shakthi.  He was also involved in the Smiling Buddha tests, conducted in 1974.  He was awarded the fourth highest civilian award of the Padma Shri, by the Government of India, in 1999.

Libya and weapons of mass destruction: Libya possesses chemical weapons and ballistic missiles and previously pursued nuclear weapons under the leadership of Muammar Gaddafi.  On 19 December 2003, Gaddafi announced that Libya would voluntarily eliminate all materials, equipment and programs that could lead to internationally proscribed weapons, including weapons of mass destruction and long-range ballistic missiles.  Libya signed the Nuclear Non-Proliferation Treaty (NPT) in 1968 and ratified it in 1975, and concluded a safeguards agreement with the International Atomic Energy Agency (IAEA) in 1980.  The United States and the United Kingdom assisted Libya in removing equipment and material from its nuclear weapons program, with independent verification by the IAEA.

Nuclear weapons testing: Nuclear weapons tests are experiments carried out to determine the effectiveness, yield, and explosive capability of nuclear weapons. Throughout the twentieth century, most nations that developed nuclear weapons tested them.  Testing nuclear weapons can yield information about how the weapons work, as well as how the weapons behave under various conditions and how personnel, structures, and equipment behave when subjected to nuclear explosions.  Nuclear testing has often been used as an indicator of scientific and military strength, and many tests have been overtly political in their intention; most nuclear weapons states publicly declared their nuclear status by means of a nuclear test.

Physicist: A physicist is a scientist who has specialized knowledge in the field of physics, the exploration of the interactions of matter and energy across the physical universe.

India and weapons of mass destruction: India possesses weapons of mass destruction in the form of nuclear weapons and, in the past, chemical weapons. Though India has not made any official statements about the size of its nuclear arsenal, recent estimates suggest that India has 110 nuclear weapons consistent with earlier estimates that it had produced enough weapons-grade plutonium for up to 75–110 nuclear weapons.  In 1999 India was estimated to have 800 kg of separated reactor-grade plutonium, with a total amount of 8300 kg of civilian plutonium, enough for approximately 1,000 nuclear weapons.  India is not a signatory to the 1968 Nuclear Non-Proliferation Treaty (NPT), which it argues entrenches the status quo of the existing nuclear weapons states whilst preventing general nuclear disarmament.

Rajagopala Chidambaram: Rajagopala Chidambaram (born 12 November 1936, PhD), is an Indian Physicist who is known for his integral role in India's nuclear weapons program; he coordinated test preparation for the Pokhran-I (1975) and Pokhran-II (1998).

Italian nuclear weapons program: The Italian nuclear weapons program was an effort by Italy to develop nuclear weapons in the late 1960s and early 1970s.  After abortive proposals to establish a multilateral program with NATO Allies in the 1950s and 1960s, Italy launched an indigenous nuclear weapons program, including testing a ballistic missile.  The program ended in 1975 upon Italy's accession to the Non-Proliferation Treaty.  Currently, Italy does not produce or possess nuclear weapons but takes part in the NATO nuclear sharing program.

Iraq and weapons of mass destruction: The fifth president of Iraq, Saddam Hussein, was internationally condemned for his use of chemical weapons during the 1980s campaign against Iranian and Kurdish civilians during and after the Iran–Iraq War.  In the 1980s, Saddam pursued an extensive biological weapons program and a nuclear weapons program, though no nuclear bomb was built.

Supporting paragraphs: Rajagopala Chidambaram Physicist
Answer: physics