1. EPAC2002 European Particle Accelerator Conference
2002, La Villette, Paris
~850 delegates from 33 countries
48 invited papers given
30 contributed oral presentations
~900 poster presentations
4 ½ days of sessions
Industrial exhibition
Technology transfer / Industry
EPAC prizes
23 October 2002
P.R.Norton RAL PPD

2. News from the laboratories
CERN – LHC (R Schmidt)
Fairly upbeat, but stressed the complexity of the LHC
Mentioned electron-cloud problems (see later)
Very high stored energy in beams – careful beam cleaning needed
String 2 test – full size model of LHC cell - ongoing
23 October 2002
P.R.Norton RAL PPD

3. Tevatron Run II (Church)
Many problems encountered
Transverse emittance of antiprotons in accumulator – transfer efficiency low – caused by intra-beam scattering
Antiproton lifetime caused by long-range beam-beam interaction in Tevatron
Remedies planned include 132 ns bunch separation instead of 396 but need to remove parasitic collisions
23 October 2002
P.R.Norton RAL PPD
9 Oct: Lpeak

4. B factories (KEK-B and PEP II)
Both B factories doing very well
PEP II exceeded its design L by 1.5
KEK-B design L is 3x higher and not yet achieved, but exceeds PEP II
Electron cloud effect (more later) causes single-bunch blow-up of LER (e+)
Both machines have wound G solenoids covering field-free region to reduce the effect
23 October 2002
P.R.Norton RAL PPD

5. EPAC2002 prizewinners Frank Zimmermann Kurt Hübner 23 October 2002
P.R.Norton RAL PPD

6. Prize Citations Frank Zimmermann Kurt Hübner
“for his many important contributions to accelerator physics. In particular he contributed significantly to the understanding of fast ion and electron cloud instabilities….”
Kurt Hübner
“for his excellent leadership in the field of accelerator physics and technology. He has provided guidance for generations of accelerator physicists and engineers, thereby contributing immensely to the prosperity of accelerators at CERN and many other laboratories around the world”
23 October 2002
P.R.Norton RAL PPD

7. Electron Cloud Instability
This arises for positive beams
Synchrotron radiation strikes the wall and ejects electrons
These can then generate further electrons (multipacting)
The interaction of the beam with the electrons has several unpleasant effects
Beam emittance blow-up
Heat load (especially for LHC)
Vacuum
23 October 2002
P.R.Norton RAL PPD

8. Animation of instability
23 October 2002
P.R.Norton RAL PPD

9. Remedies Shape of beam pipe Surface coating Conditioning
Solenoidal windings (KEK-B, PEP II)
Bunch spacing
23 October 2002
P.R.Norton RAL PPD

10. Fast beam ion instability
This affects negative beams
Ions produced from residual gas interact with the negative beam
Seen at some light sources (eg Spring-8) and in the KEK-B HER
Leave gaps in bunch train
Need ultra-good vacuum in LC damping rings
23 October 2002
P.R.Norton RAL PPD

11. Japanese neutrino factory
KEK scheme based on FFAGs
Large acceptance and no cooling
Small FFAG already built
Interesting idea
23 October 2002
P.R.Norton RAL PPD