How have advances in particle accelerator technology helped

in the discovery of quarks?

How have advances in particle accelerator technology helped in the discovery of quarks?

•Increasing available energy to convert into matter.

•Matter/Anti-matter colliders.

•Detectors.

Quarks•Quarks are fundamental particles; they compose all matter.

•Quarks carry both mass and charge.

•Only up/down quarks are stable; charm/strange and top/bottom must be produced in accelerators and decay shortly thereafter.

Quarks•Quarks were theorizes in 1961 by Dr Murray Gell-Mann as a mathematical organization of sub-atomic particles.

•Neutrons and protons are composed of quarks:

•U=+2/3 , D=-1/3 hence

•Proton=(2/3)+(2/3)-(1/3)=1

•Neutron=(2/3)-(1/3)-(1/3)=0

E=MC2

• Mass and energy are interchangeable

•E2 = m2c4 + p2c2 ; p=(mv)/(sqrt(1-(v2/c2)))

•For matter / target collisions:

•Rest mass(E=mc2) + momentum of accelerated particle = (rest mass of resultant particles + momentum of resultant particles) + (Rest mass of accelerated particle + residual momentum of accelerated particle)

•For matter / anti-matter collisions:

•Rest masses + momentums of accelerated particles = (rest mass of resultant particles + momentum of resultant particles)

Accelerator types•Electrostatic accelerators:

•Accelerate particles across a potential difference

•Cyclotrons

•Utilize an oscillating electric field to accelerate particles confined to a circular path in a magnetic field.

•RF linear accelerator

•Utilize an oscillating electric field to accelerate particles in a straight path.

•Synchrotrons

•Accelerate particles with an RF accelerator while using magnets to deflect the particles in a circular path.

Energy•Electrostatic accelerators:

•Are limited by leakage of electrostatic charge.

•Cyclotrons

•Are limited by the maximum magnetic field that can be uniformly generated in the accelerating section. Maximum energy is 50 MeV.

•Synchrotrons

•Solve the problem that the cyclotron has by gradually increasing the magnetic field at the deflection points. However electrons lose energy by emitting radiation. These accelerators are used to accelerate protons / anti-protons. Maximum energy is 1.2 TeV.

•RF linear accelerator

•The preferred method of accelerating electrons / positrons. Due to the linear path, radiation is not emitted by electrons allowing maximum energies of 50 GeV to be imparted.

Detectors•Cloud chambers

•Particles condense a super-saturated vapor.

•Bubble chambers

•Particles boil a super-heated liquid. Their trajectory is altered by a magnetic field so their momentum can be quantified.

•Solenoid detectors

•Particles pass through CCD sensors an well as an array of Geiger counters. They are subjected to a magnetic field they pass through these sensors. The sensors record the path that the particle takes thus quantifying it’s momentum

The technological increases in particle accelerators that led to the discovery of quarks are:

• Development of RF accelerators.

•Development of solenoid detectors.

•Technique of matter / anti-matter colliders

•The increases in beam-line energy due to the development of RF linear accelerators, allowed accelerators to impart the energy necessary to produce quarks not found in nature.

•The development of solenoid detectors allowed the detection of quarks and the quantification of their masses.

•The technique of matter / anti-matter collisions converts the rest mass of the accelerated particles directly into energy available for the production of resultant particles.

The question:•How have advances in particle accelerator technology helped in the discovery of quarks?

The answer:•Advances in particle accelerator technology helped in the discovery of quarks by increasing the energy available for conversion into mass as well as providing an increased ability to observe particles produced.

Product•100 KeV electrostatic accelerator.

•Accelerates electrons.

•Approximates 1930s technology.

•Electrons are placed on the sphere of the Van De Graaf generator. They discharge into the cathode of the accelerator and are accelerated toward the grounded target.

SourcesHan, M Y. Quarks and Gluons. Singapore: World Scientific, 1999.

Bromley, Allan Ed. Large Electrostatic Accelerators. Amsterdam: North-Holland, 1974.

“SLAC Virtual Visitor Center”. 30 July 2002. Stanford University. 15 Jan. 2003 <http://www2.slac.stanford.edu/vvc/Default.htm>

Trefil, James S. From Atoms to Quarks. New York: Charles Secribner's Sons, 1980.

Wille, Klaus. The Physics of Particle Accelerators. New York: Oxford, 1996.