Author: Scott, D.J.
Paper Title Page
MOPWA061 A New Tool for Longitudinal Tomography in Fermilab's Main Injector and Recycler Rings 816
 
  • N.J. Evans, S.E. Kopp
    The University of Texas at Austin, Austin, Texas, USA
  • P. Adamson, D.J. Scott
    Fermilab, Batavia, USA
  
  Funding: U.S Department of Energy
We are de­vel­op­ing soft­ware to com­pute to­mo­graphic re­con­struc­tions of lon­gi­tu­di­nal phase space dis­tri­b­u­tions in the Fermi Na­tional Ac­cel­er­a­tor Lab­o­ra­tory Main In­jec­tor and Re­cy­cler rings using data from ex­ist­ing re­sis­tive wall cur­rent mon­i­tors to di­ag­nose beam qual­ity at in­jec­tion and pro­vide input dis­tri­b­u­tions for sim­u­la­tion of losses. Build­ing on the al­go­rithm de­vel­oped by *S. Han­cock et al. at CERN the soft­ware is able to process a full syn­chro­tron pe­riod of a Booster batch of 81 bunches with 18.94 ns spac­ing and a sam­pling rate of 2.5 GHz, in < 30 sec, or every ~270 in­jec­tions. Pro­cess­ing an en­tire in­jec­tion opens up the pos­si­bil­ity of in­ves­ti­gat­ing cou­pled bunch in­sta­bil­i­ties via to­mog­ra­phy. To speed re­con­struc­tion for use on a full in­jec­tion, phase space maps are cre­ated once for a given set of pa­ra­me­ters and saved for in­jec­tions with sim­i­lar ma­chine set­tings. We pre­sent an overview of the sys­tem and stud­ies done on the ef­fect of small er­rors pre­sent in­clud­ing: ran­dom noise, mis­match be­tween sam­pling rate and ma­chine pe­riod, er­rors in lo­cat­ing bunch cen­ters, and trig­ger jit­ter.
*Tomographic Measurements of Longitudinal Phase Space Density; 1998 ed. - Hancock, S et al - CERN-PS-98-030-RF