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Peake, D.J.

Paper Title Page
TUPD026 Impedance Effects in the Australian Synchrotron Storage Ring 1979
 
  • R.T. Dowd, M.J. Boland, G. LeBlanc, Y.E. Tan
    ASCo, Clayton, Victoria
  • D.J. Peake
    Melbourne
  
 

The Aus­tralian Syn­chrotron stor­age ring must main­tain a sta­ble elec­tron beam for user op­er­a­tions. The impedance char­ac­ter­is­tics of the stor­age ring can give rise to in­sta­bil­i­ties that ad­verse­ly af­fect the beam qual­i­ty and need to be well un­der­stood. Col­lec­tive ef­fects driv­en by the re­sis­tive wall impedance are par­tic­u­lar­ly rel­e­vant at the Aus­tralian syn­chrotron and their strengths are en­hanced by small gap in­ser­tion de­vices, such as IVUs. This study will ex­plore the impedance is­sues iden­ti­fied in the Aus­tralian Syn­chrotron stor­age ring and cur­rent mit­i­ga­tion tech­niques.

  
WEPEB027 Preliminary Operational Experiences of a Bunch-by-bunch Transverse Feedback System at the Australian Synchrotron 2743
 
  • D.J. Peake, R.P. Rassool
    Melbourne
  • M.J. Boland, R.T. Dowd, Y.E. Tan
    ASCo, Clayton, Victoria
  
 

The Aus­tralian Syn­chrotron stor­age ring has a re­sis­tive wall in­sta­bil­i­ty in the ver­ti­cal plane. Present­ly this in­sta­bil­i­ty is being con­trolled by in­creas­ing the ver­ti­cal chro­matic­i­ty. How­ev­er new in-vac­u­um in­ser­tion de­vices that sig­nif­i­cant­ly in­crease the ring impedance may de­mand chro­mat­ic cor­rec­tions be­yond the ca­pa­bil­i­ties of the sex­tupole mag­nets. A trans­verse bunch-by-bunch feed­back sys­tem has been com­mis­sioned to com­bat the ver­ti­cal in­sta­bil­i­ty* and pro­vide beam di­ag­nos­tics**. A high fre­quen­cy nar­row band mode that could not be damped was ini­tial en­coun­tered with IVUs at min­i­mum gap pre­vent­ing the sys­tem from being im­ple­ment­ed dur­ing user beam. Tun­ing of the bunch fill pat­tern, the dig­i­tal fil­ters and map­ping out the sys­tem re­sponse lead to a con­fig­u­ra­tion for user mode op­er­a­tions.


* Spencer, M.J. et. al. EPAC'08, Genoa, Italy
** Peake, D.J. et. al. PAC'09, Vancouver, Cananda