Are the large "cold" physical facilities under the epidemic OK?

Are the large "cold" physical facilities under the epidemic OK?

Italy's Virgo gravitational wave observatory was forced to close. Image source: Nature website

International War "Outbreak"

The vast and sparsely populated South American prairies of Argentina seem to be the ideal place to maintain social distance. The Pierre Auger Observatory in Mendoza is the world's largest cosmic-ray observatory. It consists of more than 1,600 car-sized plastic cans filled with water and scattered scattered about 3,000 square kilometers of land. In the past, only grazing cows occasionally came to accompany them.

However, this inaccessible savannah also failed to escape the "magic palm" of new crown pneumonia. Because Argentina is now closed, maintenance personnel cannot regularly repair the detector, including replacing defective batteries. "The equipment will not be able to work due to chronic lack of maintenance," said Project Manager Inge Alcott. "At present, the observatory has to shut down its fluorescence detector, whose mission is to monitor ultraviolet light in cosmic rays."

The new crown pneumonia epidemic is raging around the world, and the Pierre Auger Observatory is not the only "big physics" facility that has been hit. Many large physics installations that seem to be "high-cold" now have to reduce running time or even pause completely. Of course, there are still some who are still holding their ground and continue to reveal the mysteries of the universe for us.

Closed door thank you remote office

Due to multi-state closure measures in the United States, some large laboratories in the United States have to suspend operations.

The United States Department of Energy (DOE) has 17 national laboratories, most of which have switched to remote office mode, and many major experiments have also been stopped. For example, an accelerator at Brookhaven National Laboratory in New York State has completed data acquisition on March 20, "three months earlier than originally planned"; the nuclear facility at Lawrence Livermore National Laboratory in California Fusion National Ignition Facility (NIF) has also been turned off. However, the Department of Energy's synchrotron radiation sources and four supercomputing centers are still firmly on the battle front, contributing to the response to the new crown pneumonia epidemic.

In addition, the world's largest particle physics laboratory, the European Nuclear Research Center (CERN) near Geneva, Switzerland, had to suspend the upgrade of the Large Hadron Collider (LHC).

Unattended operation remains

Of course, there are still some large physics projects that are not afraid of the epidemic, and continue to collect data, such as the SNOLAB underground experiment in Canada. The experiment aims to detect dark matter and neutrinos. Leader Nigel Smith said that some large-scale international cooperation experiments have been conducted by team members around the world. For a long time, these experiments can be performed without on-site support. Keep running. "This is the case with SNOLAB," Smith said. "The remote operation capability has been built into the system and its main detector is still running." Nevertheless, the SNOLAB experiment has also been affected, and planned upgrades will have to be delayed.

Gran Sasso National Laboratory in Italy has a similar fate as SNOLAB. Italy has now locked its country, and the laboratory's upgrade and construction work has been suspended, but its neutrino and dark matter experiments are still running. "The Gran Sasso National Laboratory itself is designed to be unattended," spokesman Roberta Antolini told Nature.

The laser interference gravitational wave observatory (LIGO) in Livingston, Louisiana, and Hanford, Washington, and the Virgo gravitational wave observatory near Pisa, Italy, were also closed on March 27 to protect employees. health. A spokesman for Virgo and physicist Joe Vandenbrand of the Dutch National Institute of Atomic Physics said that as travel to Italy has become impossible, a complete shutdown is the only way to protect employees.

The two observatories originally planned to end their current round of data collection at the end of April this year, and major upgrades were made in May to double the sensitivity and restart in 2022. "But all arrangements are now impossible." .

But this does not mean that scientists have nothing to do. In the latest run from April 1, 2019, LIGO and Virgo collected a large amount of data, including 56 "candidate" collision events. The international LIGO-Virgo cooperation group is now busy analyzing these data, which is expected to continue for several months. time. And, fortunately, the team is still able to use facilities such as the Leibniz Supercomputing Center in Germany. "As long as high-performance computing devices and the Internet continue to operate, we should be able to do our job," the researchers said.

Lucky plus methodical

Of course, not all large physics installations have been impacted, and there are always some "lucky ones" who have temporarily avoided the disaster. For example, the European Spallation Neutron Source in Lund, Sweden, is the world's premier neutron beam facility. At present, the construction of the European spallation neutron source is proceeding in an orderly manner and is expected to be completed by 2025.

Japan's Kamioka Observatory is home to the "Super Kamioka" neutrino detector and the "Kamioka Gravitational Wave Detector" (KAGRA). It has not been affected by the epidemic for the time being. KAGRA member Ayako Saitama said her team has been working for several months to debug a new detector that began operating in February.

When we set our sights on southern China, we will also find a "lucky man". The Jiangmen Neutrino Experiment (JUNO) in China is an underground detector and is still under construction. "The majority of people are now back to work," Liu Lei, director of the Engineering Office of JUNO, told Nature magazine. She estimates that the project will be delayed by up to three months, and experiments are still expected to begin in 2022.

Amundsen-Scott Antarctic Station is currently out of reach of the new crown virus. With the end of summer, flights to and from Antarctica have been stopped in February, and staff in the Antarctic winter have been quarantined long enough. At present, The new crown virus did not visit this place. The "IceCube" neutrino observatory located here is still pure land. IceCube spokesman Francis Halzen said: "The detector has been operating as usual and transmitting data north."

The epidemic will eventually pass, and everything will be as it was yesterday. When the world ’s pyrotechnic atmosphere pervades again, these “high-cold” devices that do not stick to pyrotechnics will continue to serve as human eyes and ears, revealing the mysteries of the universe and listening to the voice of the universe. (Reporter Liu Xia)