The Pierre Auger Project

1. The Pierre Auger Project By Megan Edwards Bancroft-Rosalie

2. Pierre Auger • Can be considered as the discoverer of the giant air showers in 1938 generated by the interaction of very high-energy cosmic rays with the earth's atmosphere. • He devoted his professional life to experimental physics in the fields of: • Atomic physics. • Nuclear physics. • Cosmic ray physics.

3. Collaboration • The Pierre Auger project includes more than 250 scientists from Argentina, Armenia, Australia, Bolivia, Brazil, China, the Czech Republic, France, Germany, Greece, Italy, Japan, Mexico, Poland, Russia, Slovenia, the United Kingdom, the United States, and Vietnam.

4. Location • The Pierre auger project had a series of workshops in Paris, Adelaide, Tokyo, and at Fermilab in 1995. • The leaders in these workshops were professors Jim Cronin of the university of Chicago and Alan Watson of the university of Leeds. The design group for the auger project hosted by Fermilab, produced a design report containing a reference design and a cost estimate for the proposed detector.

5. Equipment I • Fluorescence telescope • This experiment uses the strengths of both surface detector arrays and fluorescence detectors.

6. Equipment II • The Pierre auger observatory will contain four fluorescence detector sites. Three will view the interior detection volume from positions on the array perimeter, and a fourth site will be placed near the center of the array. Each site will view the atmosphere over an elevation range from 2-30o. The perimeter sites view an azimuth range of 180o and the central site views over the full 360o. A total of thirty 3-m diameter mirrors capture the light and focus it onto photomultiplier cameras. Over 13,000 photomultipliers are used in total to view the sky with 1.5o pixels. Despite the low efficiency of the fluorescence process, the huge showers produced by the highest energy cosmic rays can be viewed up to 30 km away.

7. Plans • Auger will detect the shower in two ways. Twenty four hours a day, an array of over 1600 particle detectors will measure shower particles as they hit the ground, which will allow a reconstruction of the shower providing measures of the original cosmic ray's energy, arrival direction, and mass. During clear, moonless nights, the showers will be viewed as they traverse the atmosphere. The passage of the showers will cause the atmosphere to fluoresce, and the faint UV light is detected by arrays of large mirrors equipped with fast photomultiplier image arrays.

8. Goals: The purpose of the Pierre auger project and observatory is to study the masses of ionizing radiation, cosmic rays, which are constantly striking the earth.The Pierre auger observatory project is an effort to study the highest energy cosmic rays. There are two giant detector array hemispheres which will consist of 1600 particle detectors and an atmospheric fluorescence detector. The objective of the arrays is to measure the arrival direction, energy, and mass composition of cosmic ray air showers above 1019 eV.