1. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March possible solutions for the electron-cloud problem  suppress e- build up reduce e- yield change e- dynamics change beam parameters  stabilize the beam feedback change beam parameters Joint CARE-HHH-APD, CARE-ELAN and EUROTEV-WP3 mini-Workshop on Electron Cloud Clearing Electron Cloud Effects and Technological Consequences, CERN, March 1-2, 2007CARE-HHHCARE-ELANEUROTEV ep feedback MINI-workshop (March 13 to March 15, 2007) at Bloomington Indiana

2. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March ECL2 workshop structure 28.02.tour of NEG facility 01.03. morning overview & simulations technological solutions I 01.03. afternoon technological solutions II simulation codes + analysis 02.03. morning beam measurements I beam measurements II 02.03. afternoon impedance issues studies, designs, & plans http://indico.cern.ch/conferenceOtherViews.py?view=standard&confId=11937

3. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March ECL2 highlight: visit of NEG facility

4. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March ECL2 highlight: dinner with enamel experts

5. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March ECL2 highlight: 1 st presentation of prototype enamel chamber

6. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March ranking of solutions modeling prototypes beam experiments suppression efficiency impedance vacuum issues implications & cost

7. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March NEG coating NEG on Al surface

8. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March grooves (M. Pivi et al, SLAC)

9. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March conventional clearing electrode (DAFNE) - now removed from the ring

10. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March e- cloud killer prototyped by Texas A&M NEG-coated 100-  m copper-foil electrode with 100-V bias voltage

11. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March double enamel coating – the new e- cloud killer (F. Caspers, F.-J. Behler, P. Hellmold, J. Wendel)

12. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March “slotted” surface standard chamber “slotted” chamber W. Bruns

13. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March electretes another interesting solution proposed by Fritz during the workshop permanently charged material, e.g. teflon subjected to e- bombardment during production (used e.g. for microphones & air filters) either permanent electric field sustained over several years, or self-charged by the beam field may allow for in-situ upgrade of LHC and SPS

14. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March pros and cons – electrodes vs NEG clearing electrodeNEG install onceregular activation needed never demonstrated for bunched e-? demonstrated in many machines for ions: shaking + clearing helpful good for vacuum efficient for ISR coasting beam e- long-term stability? impedance?

15. possible solutions for the e- cloud problem – SPS upgrade meeting - Frank Zimmermann, 21 March possible solutions for PS2 & SPS PS2SPS slotted chamber (Warner) enamel electrodes (Fritz) electrete insert (Fritz) NEG or other coating air baked copper (C.S.) …? NEG, TiN or other coating (Elena S.+Paolo C.) in-situ grooves (Elena) electrete insert (Fritz) air baked copper (C.S.) …?