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.
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.
JINR, Dubna
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.
INFN/BA, Bari
BINP, Novosibirsk
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.