Panjab University scientists have succeeded in developing the first resistive plate chamber to be used in the project to upgrade the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider, the world’s largest and most powerful particle accelerator in Geneva, for experiments on the Higgs boson or ‘God Particle’.
The scientists said aside from the Bhabha Atomic Research Centre, Mumbai, PU was the first higher education institution where such a lab was set up to assemble these detectors. Over the next three months a team of 15 scientists and PU students will work round the clock to provide resistive plate chamber (RPC) plates used for particle detection as part of the CMS detector. The laboratory, set up on the ground floor of the physics department building, cost nearly Rs 2.5 crore.
“Earlier our teams went to Geneva and Mumbai to work on similar project tasks. With the lab having been set up on the campus we’ll now be sending nine RPCs to be used in the project,” said JB Singh, professor physics at Panjab University under whose guidance the project is being conducted.
The scientists remain in the laboratory round the clock as air pressure and temperature have to be constantly monitored and even a slight change could create problems. A closed-loop gas recycle unit has also been installed within the lab to preclude any damage to the environment by gases. The Freon gas used in the lab is considered to cause depletion of the ozone layer. “But it’s being recycled in the lab,”” assistant professor of physics Vipin Bhatnagar, who has been associated with the project, said.
Bakelite sheets 1.5 by 1 metres in size, made in Italy and later conditioned in South Korea, are put to physical, pressure and leakage tests and later a 10,000 volt electric current is passed through them at 12-hour intervals. “If the results are satisfactory the plates are then assembled and the readout strips, etc, are put in, and the process is re peated ag ain. The plate is tested over a 15-day period again,” Singh said, adding since the plates had a life of 15 years they had to be repeatedly tested to ensure there was no margin for an error. It takes around a fortnight to prepare a resistive plate chamber, which includes initial checks, assembling and testing, with another 15 days spent in observation. All the nine plates will be shipped to Geneva beginning May.
“We’re updating scientists in Geneva on the results we’re getting here every day. The next step will be taken only when the Geneva team approves the results,” he added.