Telescope Array Project facts for kids
The Telescope Array project is a big science effort involving scientists and schools from Japan, the United States, Russia, South Korea, and Belgium. This project is designed to study special events called air showers. These showers are caused by super-powerful particles from space called ultra-high-energy cosmic rays. The project uses two main ways to observe these showers: special detectors on the ground and telescopes that look at the sky. It's located in the desert of Millard County, Utah, United States, about 1,400 meters (4,600 feet) above sea level.
Quick facts for kids Telescope Array Project |
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| Location | Millard County, Utah, US | |
| Built | 2003-2007 | |
| First light | 2008 | |
| Telescope style | gamma-ray telescope | |
| Website | www.telescopearray.org | |
Contents
What is the Telescope Array?
The Telescope Array observatory is a special system that combines two ways of detecting cosmic rays. It uses an array of 507 surface detectors (SD) spread out on the ground. These detectors measure tiny charged particles that hit the Earth's surface. It also has three special telescope stations that look at the night sky. These are called fluorescence stations.
Each fluorescence station also has a LIDAR system. This system helps scientists check the atmosphere. The ground array covers a huge area, about nine times larger than a similar project called AGASA.
This combination of detectors allows scientists to see the full development of an air shower. They can see how it grows in the atmosphere and how it spreads out on the ground. When a cosmic ray hits Earth's atmosphere, it creates an air shower. The fluorescence telescopes measure the faint light given off by this shower. At the same time, the surface detectors record the particles that reach the ground.
At the very center of the ground array is the Central Laser Facility. This facility is used to check the atmosphere and make sure the detectors are working correctly.
How Do Surface Detectors Work?
The surface detectors are the panels spread across the ground. They become active when tiny particles from an air shower pass through them. Inside each detector is a special plastic material called a scintillator. When particles pass through this plastic, it glows with tiny flashes of light.
These flashes of light are then collected by special fibers. The fibers send the light to sensors called photomultiplier tubes. These sensors turn the light into electrical signals. The electronic parts inside the detectors then process these signals. This makes the detectors very accurate, similar to the AGASA experiment.
The surface detectors are placed in a grid pattern over an area of 762 square kilometers (about 294 square miles). Each detector is 1.2 kilometers (0.75 miles) away from its neighbors. Each surface detector weighs 250 kilograms (550 pounds). It includes a power supply, two layers of scintillator detectors, and electronics. Solar panels power the system. A battery stores energy, allowing the detector to work for a week even without sunlight. Each scintillator layer is 1.2 centimeters (0.5 inches) thick and covers an area of 3 square meters (32 square feet).
Fluorescence Detector Stations
The Telescope Array has three fluorescence detector (FD) telescope stations. These detectors work by measuring the faint light that air showers give off in the atmosphere. This is similar to how older projects like Fly's Eye and HiRes worked.
Each FD telescope has a main mirror made of 18 smaller mirrors. It also has a camera. These cameras have 256 special sensors called photomultiplier tubes (PMTs). These PMTs are very sensitive to the ultraviolet light produced by cosmic ray air showers.
The three stations are placed in a triangle shape, about 35 kilometers (22 miles) apart. The Central Laser Facility is near the middle of this triangle. Each of the three stations has 12 to 14 telescopes. These telescopes can see light from 3 to 33 degrees above the horizon. The three sites are named Black Rock Mesa (BRM), Long Ridge (LR), and Middle Drum (MD).
By combining the information from all three sites, scientists can figure out:
- How much energy the original cosmic ray had.
- Where the cosmic ray came from in space.
- The highest point an air shower reached in the atmosphere.
| Black Rock Mesa | 39°11′18″N 112°42′42″W / 39.18833°N 112.71167°W | |
| Long Ridge | 39°12′28″N 113°07′17″W / 39.20778°N 113.12139°W | |
| Middle Drum | 39°28′22″N 112°59′37″W / 39.47278°N 112.99361°W | |
| Central Laser Facility | 39°17′49″N 112°54′31″W / 39.29694°N 112.90861°W |
Cosmic Ray Center
The Lon and Mary Watson Millard County Cosmic Ray Center opened on March 20, 2006. It is located in Delta, Utah. This building is the main office and data center for the Telescope Array Project. Scientists use it to process all the information collected by the detectors.
In October 2011, a new visitor center opened at the Cosmic Ray Center. It has exhibits about the history of cosmic ray research in Utah. You can also learn about the Telescope Array itself. The center also has a display about the nearby Topaz internment camp. This was a historical site where U.S. citizens of Japanese descent were held during World War II.
TALE: Looking for Lower Energy Cosmic Rays
TALE stands for the Telescope Array Low Energy extension. Its goal is to observe cosmic rays that have slightly less energy than the main Telescope Array focuses on. These energies are between 30 quadrillion and 10 quintillion electronvolts.
TALE added 10 new telescopes to the Middle Drum observatory site. This means Middle Drum now has 24 telescopes in total. These new telescopes allow the station to see higher up in the sky. This helps scientists see the full development of air showers caused by lower energy cosmic rays. Seeing the full shower is very important for figuring out what kind of particle the original cosmic ray was made of.
The TALE project also has a special set of scintillator stations on the ground. These stations are placed closer together, at 400 meters (1,300 feet) and 600 meters (2,000 feet) apart. They then connect to the main Telescope Array, where detectors are 1,200 meters (3,900 feet) apart. These closer stations help measure the particles that hit the ground from lower energy air showers.
TARA: Detecting Cosmic Rays with Radar
The Telescope Array RADAR (TARA) Project is working on new ways to detect cosmic rays. Current methods have some challenges. For example, fluorescence telescopes can only work at night when it's clear. This means they can only be used about 10% of the time. Ground detectors can run all day, but they need a lot of land, so they have to be in remote places.
The TARA Project aims to create a bistatic radar detection system. Think of it like how bats use sound to "see" things. This system would use radio waves to detect cosmic rays. The goal is for it to work 24 hours a day, no matter the weather or time. It would also be much cheaper than current systems.
In September 2012, the W. M. Keck Foundation gave researchers at the University of Utah a $1 million grant. This money is for developing the bistatic radar system. This new system will be built next to the existing Telescope Array. It will use TV transmitters and digital receivers to find the range, direction, and strength of cosmic rays. This will help scientists trace them back to where they came from. Once finished, this new facility will be called the W.M. Keck Radar Observatory.
