• A. Saa Hernandez, H. Mueller, N. Pyka, P.J. Spiller
  GSI, Darmstadt
• U. Ratzinger
  IAP, Frankfurt am Main

With the abil­i­ty to ac­cel­er­ate heavy ions up to an en­er­gy of 32 GeV/u, the SIS300 su­per­con­duct­ing (sc) syn­chrotron is a cen­tral part of the new FAIR fa­cil­i­ty at GSI-Darm­stadt. SIS300 will pro­vide beams with a 20-fold in­crease in en­er­gy and, by means of a stretch­er mode or a fast ramped mode (1 T/s), 100-10000 times high­er av­er­age in­ten­si­ty. The beam from SIS300 will be ex­tract­ed to­wards the ex­per­i­ments using res­o­nant slow ex­trac­tion, thus SIS300 be­comes the first su­per­con­duct­ing syn­chrotron world­wide with this fea­ture. Cou­pling and per­sis­tent cur­rents are the main prac­ti­cal lim­i­ta­tion for op­er­a­tion of sc mag­nets at high ramp­ing rates and long slow ex­trac­tion plateaus. The ef­fect of the per­sis­tent cur­rents, which are time de­pen­dent and de­pend as well on the mag­net's his­to­ry, is es­pe­cial­ly crit­i­cal for slow ex­trac­tion at low en­er­gies. These ef­fects de­ter­mine the tol­er­ances on mag­net­ic com­po­nents. In order to ad­dress this issue, de­tailed sim­u­la­tions of beam dy­nam­ics at slow ex­trac­tion have been per­formed. In par­tic­u­lar, the op­ti­miza­tion of the lat­tice and its op­ti­cal pa­ram­e­ters for a low-loss ex­trac­tion in the pres­ence of steady and time-de­pen­dent field com­po­nents will be pre­sent­ed.