Lecture 2 Overview of Accelerators II ACCELERATOR PHYSICS

Lecture 2 - Overview of Accelerators II ACCELERATOR PHYSICS MT 2011 E. J. N. Wilson Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 1

Lecture 2 – Overview II- Contents Weak focusing in a synchrotron Strong focusing The “n-value” Cosmotron people Strong focusing CERN at BNL CERN 25 Ge. V PS CERN’s rings SPS Center of mass v. Fixed target The first collider -Ad. A ISR AND PS Luminosity SPS Physics of electrons v protons LEP Superconducting magnets Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 2

Weak focusing in a synchrotron The Cosmotron magnet Vertical focussing comes from the curvature of the field lines when the field falls off with radius ( positive n-value) Horizontal focussing from the curvature of the path The negative field gradient defocuses horizontally and must not be so strong as to cancel the path curvature effect Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 3

The “n-value” As the C magnet saturates the n value – which is the rate of droop – increases Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 4

Cosmotron people E. Courant -Lattice Designer Snyder -theorist Lecture 2 - E. Wilson 14 Oct 2011 –- Slide Stan Livingston - Boss Christofilos - inventor 5 FOURGUYS. pct

Strong focussing Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 6

CERN at BNL Odd Dahl, Frank Goward, and Rolf Widerö (right hand trio) Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 7 Fig. 3(CERNVISITORS). pct

CERN 25 Ge. V PS Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 8

CERNS RINGS Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 9

SPS Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 10

Center of mass v. Fixed target Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 11

Ad. A - The first collider e-plus-minus Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 12

ISR AND PS Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 13 ISR+PS. pct

Luminosity Imagine a blue particle colliding with a beam of cross section area - A Probability of collision is For N particles in both beams Suppose they meet f times per second at the revolution frequency Event rate Make big Make small LUMINOSITY Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 14

SPS Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 15

Physics of the electron v. protons When we collide Protons we collide complex assemblies of three quarks Only two quarks interact Their available energy is on average only 10% of the total centre of mass energy We do not know which quarks they are Hence in some ways 100 Ge. V LEP is as good as 1000 Ge. V TEVATRON HENCE THE RETURN TO LEP AFTER SPS AND THEN LHC AFTER LEP Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 16

LEP Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 17 LEP(small). pct

Inside LEP Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 18

The Tevatron at FNAL Fermilab’s superconducting Tevatron can just be seen below the red and blue room temperature magnets of the 400 Ge. V main ring. Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 19

The Large Hadron Collider (LHC) Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 20

Superconducting magnets Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 21

Summary Strong focusing CERN at BNL CERN 25 Ge. V PS Center of mass v. Fixed target The first collider -Ad. A ISR AND PS Luminosity SPS Antiproton production and cooling CERN Antiproton Accumulator LEP Superconducting magnets Lecture 2 - E. Wilson 14 Oct 2011 –- Slide 22