Cosmic rays - the happiness of Prof. Cronin

With the famous physics invention in 1964, Professor Cronin and his colleagues opened an endless vision for humans about the natural world around, from matter and antimatter to high-energy cosmic rays. .

Aspects of James Watson Cronin

James Watson Cronin was born on September 29, 1931 in Chicago, Illinois (USA).

His father was James Farley Cronin, a classic language graduate student at the University of Chicago and from 1939 was a professor of Latin and Greek at Southern Methodist University.

His mother, Dorothy Watson, met his father at Northwestern University in a Greek class. 1951: Graduated from Southern Methodist University in mathematics and physics, Dallas, Texas.

His achievements:

- 1953: Master, University of Chicago.
- 1955: Doctor of Physics, University of Chicago.
- 1952-1955: Member of the National Science Foundation.
- 1955-1958: Research at Brookhaven National Laboratory.
- 1958-1964: Physical assistant, Princeton University.
- 1964-1971: Physics professor, Princeton University.
- From 1971: Physics professor, University of Chicago.
1980: Nobel Prize in Physics (with Van Logsdon Fitch).

Currently the emeritus professor of Chicago University; Pierre Auger Project spokesperson; member of the US National Academy of Sciences, American Academy of Arts and Sciences, American Physical Society. Professor James W. Cronin considered himself one of the most fortunate and satisfied people in the world. '' When I wonder who is the happiest on Earth? My answer is that people can't wait until they wake up in the morning to get back to their unfinished work the day before , 'Cronin said.

Cronin became interested in science when he was a Southern Methodist University student (Dallas, Texas). Later, he returned to Chicago to study for a doctorate at the University of Chicago, Illinois. In 1955, he went to Brookhaven as a PhD student. It was at Brookhaven that Cronin met Val L.Fitch.

The Cronin - Fitch team described a phenomenon that explains why our universe is primarily material rather than a balance of matter and antimatter. An article on this issue was published in 1964. However, it was not until 1984 that the scientific world realized the importance of this discovery and the Nobel Prize was awarded to this work.

Cronin continued to study the problem until 1971 when he left Princeton for the University of Chicago. His interest turned to particle physics. The particle physics experiments are great and have important implications. I want to measure them with high accuracy. People know so little, that I decided to build something. That is the birth of the Auger International Project ''.

Cosmic rays

Prof. Cronin was greatly admired by the world scientific community because of the experiment ' to give life ' in 1964 about 'particle asymmetry and counter-neutral K-mezon county', a finding that gave him the Nobel Prize in Physics 1980.

Currently Mr. Cronin is leading Pierre Auger - a world-class project to find the source of cosmic rays (cosmic rays) of the highest energy. The project currently has the cooperation of more than 250 scientists worldwide, including Vietnam. The Pierre Auger Project website is www.auger.org.

The desire to elucidate the mysteries of cosmic rays prompted this 75-year-old physicist to travel around the world to convince 18 nations and a group of scientists to participate in construction projects. $ 150 million observation decks in Argentina and Millard County (Utah, USA).

According to the design of Project Auger, only one observatory is not enough but there must be two stations at the ends of the Earth because it is necessary to monitor the whole sky at the same time. In the case of the most symmetrical, the Observatory must be placed at two poles of the Earth.

However, the practical option is to choose a location in the southern hemisphere and a point in the northern hemisphere. Finally, the plateau in Argentina and Utah in the US was chosen.

Since 1998, there have been more than 400 stations installed in the Southern Observatory and two fly-eye stations. With only the first 30 stations to operate, people began to test large-scale atmospheric showers. 2003 marked the turning point when the Auger Project reached a larger scale than other projects and from there began to provide new scientific data on the highest energy rays.

It is expected that in the next two to three years, all stations in the Southern Hemisphere will be installed and the North American station will be constructed.

According to the latest updated data, there are already dozens of measurements of very high energy levels, above 1019eV. Especially in May 2004, the detectors detected the energy level of 1020eV - Auger's target. The more cosmic ray particles at a high energy level the less the number.

One theory is that after the 1019e and 1020eV levels, this spectrum will be cut off, meaning that there is almost no higher energy particle.

However, in recent decades, scientists still measure some particles but the reliability is not high. The goal of Project Auger is to determine if the spectrum of cosmic rays is there or not .

Radio Auger will have a total of 1,600 bottles of water.Each tank contains 14,000 liters of water, which is a particle detector with a diameter of 3.6m and a height of 1.2m.It is completely dark inside, except when the energy particles pass through.When charged particles (such as muons, electrons or hadrons) fly through the detector at a faster speed than light in the water environment, they will deliver directional Cherenkov light pants.The amount of light is measured by three photomultiplier tubes with a diameter of 25cm above the capacitor detector and transmit signals to the processor.

A rain will explode light at the same time or in five or more pots.The amount of light detected reveals the energy of primary cosmic rays.The small difference in the number of detectors at many positions determines the direction of cosmic rays compared to the plane of the Earth.

Minh Son (synthesized from the Internet)