The "FFAG" and Its Two Applications In High Energy Particle Physics

The Department of Physics and Astronomy Colloquium: Prof. Sho Ohnuma, University of Hawaii at Manoa, to speak on “The "FFAG" and Its Two Applications In High Energy Particle Physics."

Abstract:

Outline:

0. Life of "builders", then and now.

1. Accelerator physics in 3 minutes.

2. What is the "FFAG"?

3. Two examples in high energy particle physics:

a) PRISM (Phase Rotated Intense Slow Muon source)

b) EMMA (Electron Model of *Many Applications* or Muon Acceleration) (* for "funding" purpose)

The original idea of using a static (in time) magnetic field ("FF" for "fixed field") for accelerating charged particles with an assured focusing action in two transverse directions was proposed by L.H.Thomas in 1938. (The first cyclotron by Lawrence worked successfully by a lucky imperfection of the magnetic field. With no radial dependence in the guiding magnetic field, which was what Lawrence intended, it would not have been possible to focus the beam in both radial and axial directions simultaneously.) "AG" of FFAG refers to the principle of strong focusing called "alternating gradient" focusing common in almost all high energy synchrotrons and circular colliders. Low energy accelerator builders in nuclear physics claim (rightfully) that they have been using the scheme for many years with terminology such as "AVF" (Azimuthally Varying Field) or even "SSC" (Spiral Sectored Cyclotrons), Proton FFAG was built for the first time at KEK(Japan) by Yoshiharu Mori and his collaborators in 2000 ( Proof-Of-Principle, "POP", 1 MeV). Since then, there have been many activities in Japan, Europe and US with diverse applications in the area of 1) cancer therapy, 2) industrial irradiation, 3) driving subcritical reactors, 4) high energy proton boosters, and 5) muon acceleration.

In this talk, I will explain the difference between two types of FFAG, traditional "scaling" type and a new idea of "non-scaling" type. The latter may accelerate muons up to 20GeV or so much faster than the ordinary synchrotrons.

Two recent examples of FFAG in particle physics, one for detecting a possible lepton flavor violation (scaling type "PRISM" in Japan) and another for establishing a feasibility of future high energy (up to 20GeV) muon acceleration (non-scaling type "EMMA" in UK), will be presented.

Ticket Information
Free

Event Sponsor
Department of Physics and Astronomy, Manoa

More Information
Dr. John G. Learned, 956-2964, jgl@phys.hawaii.edu

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