• V.A. Andreev, N.N. Alexeev, A. Kolomiets, V.A. Koshelev, V.G. Kuzmichev, S. Minaev, B.Y. Sharkov
  ITEP, Moscow

The new heavy ion high cur­rent in­jec­tor for ITEP-TWAC Fa­cil­i­ty is now under con­struc­tion at ITEP for ac­cel­er­a­tion of ions with 1/3 charge to mass ratio up to en­er­gy of 7 MeV/u and beam cur­rent of 100 mA. The 81.5 MHz RFQ sec­tion based on 4 vane res­onator with mag­net­ic cou­pling win­dows is con­struct­ed for the beam en­er­gy of 1.566 MeV/u. The RF tun­ing of RFQ sec­tion has been present­ly com­plet­ed and ba­si­cal­ly con­firms the ex­pect­ed pa­ram­e­ters cal­cu­lat­ed by 3D OPERA codes. The win­dows im­prove both az­imuthal and lon­gi­tu­di­nal sta­bi­liza­tion of the op­er­at­ing mode by in­creas­ing the sep­a­ra­tion from par­a­sitic modes. The sec­ond sec­tion of 163 MHz H-type res­onator is de­signed and in progress for con­struc­tion. Sta­tus of ma­chine con­struc­tion ac­tiv­i­ty and beam dy­nam­ics cal­cu­la­tion are pre­sent­ed.

• A.A. Drozdovsky, N.N. Alexeev, S.A. Drozdovsky, A. Golubev, A.P. Kuznetsov, Yu.B. Novozhilov, S.M. Savin, B.Y. Sharkov, V.V. Yanenko
  ITEP, Moscow

Ap­pli­ca­tion of a plas­ma lens to fo­cus­ing of ion beams has a num­ber of es­sen­tial ad­van­tages. It is im­por­tant that the fo­cus­ing ca­pa­bil­i­ties of the lens de­pend on the stage of plas­ma de­vel­op­ment. Under cer­tain con­di­tions a mag­net­ic field is lin­ear, that allow to focus the beam to a very small spot. In other con­di­tions, the mag­net­ic field is non­lin­ear, that allow for­ma­tion of hol­low and other beam struc­tures. Hol­low cylin­der-shaped beams of high en­er­get­ic heavy ions are ef­fi­cient drivers for im­plo­sion tar­gets to cre­ate mat­ter in a high­ly com­pressed state. The work deals with the study the pos­si­bil­i­ty of using a plas­ma lens to trans­for­ma­tion the den­si­ty dis­tri­bu­tion of ions in the beam. Cal­cu­la­tions and mea­sure­ments were per­formed for a C⁶⁺ and Fe²⁶⁺ beams of 200 MeV/a.u.m. en­er­gy. The ob­tained re­sults and anal­y­sis are re­port­ed.

• A. Sitnikov, N.N. Alexeev, A. Golubev, V.A. Koshelev, T. Kulevoy, S. Minaev, B.Y. Sharkov
  ITEP, Moscow
• D.H.H. Hoffmann, N.A. Tahir, D. Varentsov
  GSI, Darmstadt

Terra Watt Ac­cu­mu­la­tor pro­ject (ITEP-TWAC) is aim­ing the ac­cu­mu­la­tion of an ion beam ac­cel­er­at­ed up to 0.7 GeV/u in a stor­age ring pro­vid­ing in­ten­si­ty of heavy ions up to 10 power 12 par­ti­cles per pulse for ex­per­i­ments on heavy ion beam-plas­ma in­ter­ac­tion. For ad­vanced ex­per­i­ments on high en­er­gy den­si­ty physics the hol­low cylin­dri­cal tar­get is need­ed. A new method for RF ro­ta­tion of the ion beam is ap­plied for re­li­able for­ma­tion of the hol­low cylin­dri­cal beam. A prin­ci­ple of fast beam ro­ta­tion by using a sys­tem of the mul­ti-cell RF de­flec­tors is con­sid­ered in this paper. A four-cell H-mode de­flect­ing cav­i­ty op­er­at­ing at the fre­quen­cy of 298 MHz has been de­vel­oped; sim­i­lar 1.5 m long cav­i­ties being ap­plied for both x- and y- di­rec­tions. The shape of the de­flect­ing elec­trodes has been op­ti­mized in order to pro­vide the uni­form de­flec­tion over the whole aper­ture tak­ing into ac­count both elec­tric and mag­net­ic com­po­nents of the RF field. A de­flect­ing sys­tem and a fo­cus­ing quadrupole triplet ap­plied to the beam with the en­er­gy of 450 MeV/u and nor­mal­ized trans­verse emit­tance of 10*pi mrad*mm may form the quasi-hol­low con­fig­u­ra­tion with the inner ra­dius up to 1.5 mm and thick­ness of 1 mm.