• A.K. Gupta, P.V. Bhagwat, R.K. Choudhury
  BARC, Mumbai

The 14 UD Pel­letron Ac­cel­er­a­tor Fa­cil­i­ty at Mum­bai has re­cent­ly com­plet­ed two decades of suc­cess­ful op­er­a­tion. The ac­cel­er­a­tor is main­ly used for basic re­search in the fields of nu­cle­ar, atom­ic and con­densed mat­ter physics as well as ma­te­ri­al sci­ence. The ap­pli­ca­tion areas in­clude ac­cel­er­a­tor mass spec­trom­e­try, pro­duc­tion of track-etch mem­branes, ra­dioiso­topes pro­duc­tion, ra­di­a­tion dam­age stud­ies and sec­ondary neu­tron pro­duc­tion for cross sec­tion mea­sure­ment etc. Over the years, a num­ber of de­vel­op­men­tal ac­tiv­i­ties have been car­ried out in-house that have helped in im­prov­ing the over­all per­for­mance and up­time of the ac­cel­er­a­tor and also made pos­si­ble to ini­ti­ate va­ri­ety of ap­pli­ca­tion ori­ent­ed pro­grammes. Re­cent­ly, a su­per­con­duct­ing LINAC boost­er has been fully com­mis­sioned to pro­vide beams up to A~60 re­gion with E~5 MeV/A. As part of Fa­cil­i­ty aug­men­ta­tion pro­gram, it is planned to have an al­ter­nate in­jec­tor sys­tem to the LINAC boost­er, con­sist­ing of 18 GHz su­per­con­duct­ing ECR ion source, 75 MHz room tem­per­a­ture RFQ linac and su­per­con­duct­ing low-be­ta res­onator cav­i­ties. The de­vel­op­ment of an al­ter­nate in­jec­tor will fur­ther en­hance the uti­liza­tion ca­pa­bil­i­ty of LINAC by cov­er­ing heav­ier mass range up to Ura­ni­um. The ECR source is being con­fig­ured joint­ly with M/s Pan­tech­nik, France, which will de­liv­er a va­ri­ety of ion beams with high charge states up to ²³⁸U³⁴⁺. This paper will pro­vide de­tailed pre­sen­ta­tion of de­vel­op­ments being car­ried out at this fa­cil­i­ty.

Slides

• A.M. Porcellato, L. Boscagli, F. Chiurlotto, M. De Lazzari, D. Giora, S. Stark, F. Stivanello
  INFN/LNL, Legnaro

The av­er­age ac­cel­er­at­ing field of the ALPI 160 MHz sput­tered QWRs has been im­prov­ing with time up to reach, after the last con­di­tion­ing cycle, the av­er­age ac­cel­er­at­ing field of 4.8 MV/m @ 7 W. Such value can be ef­fec­tive­ly sus­tained in op­er­a­tion due to the in­trin­sic me­chan­i­cal sta­bil­i­ty of the sput­tered cav­i­ty whose fre­quen­cy is prac­ti­cal­ly not in­flu­enced by fluc­tu­a­tions in the bath He pres­sure. The pre­sent av­er­age cav­i­ty per­for­mance ap­proach­es the max­i­mum av­er­age ac­cel­er­at­ing field ob­tain­able in the present­ly in­stalled cav­i­ties, most of which were pro­duced by re­place­ment of Pb with Nb in the pre­vi­ous­ly in­stalled sub­strates. A high­er av­er­age value can be ob­tained in ALPI re­plac­ing the less per­form­ing units; it is in­stead nec­es­sary to sput­ter on ap­pro­pri­ate­ly built sub­strates to pro­duce QWRs which can re­li­ably ex­ceed 6 MV/m @7W. The cav­i­ty Q-curves, which were re­cent­ly mea­sured in ALPI, show a wide range of Q₀ and Q-drop, main­ly as­so­ci­at­ed with the sub­strate char­ac­ter­is­tics, but in some cases also in­flu­enced, as dis­cussed in the paper, by cryo­stat as­sem­bling pro­ce­dures and by cav­i­ty pro­duc­tion and con­di­tion­ing.

Slides

• D. E. Donets, E. D. Donets, E. E. Donets, V.M. Drobin, A.V. Shabunov, Yu. A. Shishov, V.B. Shutov, E.M. Syresin
  JINR, Dubna
• A.E. Dubinov, R.M. Garipov, I.V. Makarov
  VNIIEF, Sarov

The so-called re­flex mode of Elec­tron String Ion Source (ESIS) op­er­a­tion has been under in­tense study, both ex­per­i­men­tal and the­o­ret­i­cal at JINR dur­ing the last decade. The idea of using a tubu­lar elec­tron string ion source (TESIS) has been put for­ward re­cent­ly to ob­tain 1- 2 or­ders of mag­ni­tude in­crease in the ion out­put as com­pared with ESIS. The pro­ject is aimed at cre­at­ing TESIS and study­ing an elec­tron string in the tubu­lar ge­om­e­try. The new tubu­lar source with a su­per­con­duct­ing solenoid up to 5 T should be con­struct­ed in 2010. The method of the off-ax­is TESIS ion ex­trac­tion will be used to get TESIS beam emit­tance com­pa­ra­ble with ESIS emit­tance. It is ex­pect­ed that this new TESIS (Krion T1) will meet all rigid con­cep­tu­al and tech­no­log­i­cal re­quire­ments and should pro­vide an ion out­put ap­proach­ing 10 mA of Ar¹⁶⁺ ions in the pulse mode and about 10 μA of Ar¹⁶⁺ ions in the av­er­age cur­rent mode. An­a­lyt­i­cal, nu­mer­i­cal study of the tubu­lar elec­tron strings and the de­sign of the TESIS con­struc­tion are given in this re­port. The ex­per­i­ments with quasi tubu­lar elec­tron beams per­formed on the mod­i­fied ESIS Krion 2 are also dis­cussed there.

• V. Variale, V. Valentino
  INFN/BA, Bari
• M. Batasova, G.I. Kuznetsov
  BINP, Novosibirsk
• T. Clauser, A.C. Raino'
  Bari University INFN/BA, Bari

The charge breed­ing tech­nique is used for Ra­dioac­tive Ion Beam (RIB) pro­duc­tion in the Iso­tope Sep­a­ra­tion On Line (ISOL) method in order of op­ti­miz­ing the reac­cel­er­a­tion of the ra­dioac­tive el­e­ments pro­duced by a pri­ma­ry beam in a thick tar­get. In some ex­per­i­ments a con­tin­u­ous RIB of cer­tain en­er­gy could be re­quired. The EBIS based charge breed­ing de­vice can­not reach a real CW op­er­a­tion be­cause the high charge state ions pro­duced are ex­tract­ed by the same part where the 1+ ions are in­ject­ed, that is, from the elec­tron col­lec­tor. In this paper, an hol­low cath­ode e-gun for an EBIS in charge breed­ing op­er­a­tion has been pre­sent­ed. Fur­ther­more, a pre­lim­i­nary sys­tem de­sign to in­ject the 1+ ions from the cath­ode part will be also shown. In this way, the ions ex­trac­tion sys­tem, placed in the elec­tron beam col­lec­tor, can be left only to ex­tract the n+ ions, and then the CW op­er­a­tion, at least in prin­ci­ple, could be reached.