Wallops Balloon With BESS Payload DSC00088

BESS is a

particle physics Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) an ...

experiment An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into Causality, cause-and-effect by demonstrating what outcome oc ...

carried by a

balloon A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, and air. For special tasks, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), or light so ...

. ''BESS'' stands for Balloon-borne Experiment with Superconducting Spectrometer. BESS is a series of experiments that started in 1993, and a later incarnation, BESS-Polar, circled the Antarctic from December 13 to December 21, 2004, for a total of 8 days 17 hours and 2 minutes. This joint Japanese and American project is supported by the

Laboratory for High Energy Astrophysics A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physicia ...

(LHEA) at

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...

GSFC The Goddard Space Flight Center (GSFC) is a major NASA space research laboratory located approximately northeast of Washington, D.C. in Greenbelt, Maryland, United States. Established on May 1, 1959 as NASA's first space flight center, GSFC empl ...

and the KEK.

Overview

The mission of this experiment is to detect

antiparticle In particle physics, every type of particle is associated with an antiparticle with the same mass but with opposite physical charges (such as electric charge). For example, the antiparticle of the electron is the positron (also known as an antie ...

s in the cosmic radiation at high altitudes. It is therefore designed to be carried aloft by balloon. The central detection device is a

magnet A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nicke ...

spectrometer A spectrometer () is a scientific instrument used to separate and measure spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where the ...

, that is used to identify all electrically charged particles crossing its main detection aperture. Mission members are working on improving the sensitivity and precision of this system with each new launch.

Scientific goals

Theories of the beginning of the

Universe The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. ...

are based on the currently-known laws of

, where

matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic part ...

is created from

energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...

in such a way that equal amounts of particles and antiparticles are produced. If this is so, then an amount of

antimatter In modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding particles in "ordinary" matter. Antimatter occurs in natural processes like cosmic ray collisions and some types of radioac ...

equal to the amount of currently visible matter must exist—though there is an equal possibility the bulk of the antimatter may have been annihilated due to the mechanism of

CP violation In particle physics, CP violation is a violation of CP-symmetry (or charge conjugation parity symmetry): the combination of C-symmetry (charge symmetry) and P-symmetry ( parity symmetry). CP-symmetry states that the laws of physics should be th ...

. The aim of BESS therefore is to quantify the amount of antiparticles in the local

cosmos The cosmos (, ) is another name for the Universe. Using the word ''cosmos'' implies viewing the universe as a complex and orderly system or entity. The cosmos, and understandings of the reasons for its existence and significance, are studied in ...

and so help to decide between these alternatives. Up to this point, only

antiproton The antiproton, , (pronounced ''p-bar'') is the antiparticle of the proton. Antiprotons are stable, but they are typically short-lived, since any collision with a proton will cause both particles to be annihilated in a burst of energy. The exis ...

s have been detected, which can be produced via collisions of the cosmic radiation with

atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, ...

s in the thin atmosphere above the balloon. Therefore, two strategies are employed to obtain the value for the flux of antiparticles from outer space: * Measure the properties of the antiproton flux precisely and look for deviations from the expected behavior of antiprotons created in the atmosphere. * Look for larger antinuclei, for instance

antihelium In modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding particles in "ordinary" matter. Antimatter occurs in natural processes like cosmic ray collisions and some types of radioact ...

, that cannot be produced by collisions. Additionally, the basic properties of standard particle fluxes will be measured with high precision.

External links

BESS webpage
on the

website High energy particle telescopes Cosmic-ray experiments Balloon-borne experiments Astronomical experiments in the Antarctic {{Astrophysics-stub