摘要:

A new design of terminal pumping has been installed in an existing 3 MV Pelletron tandem accelerator. The very limited space in the high voltage terminal (total length 600 mm and diameter 600 mm and housing equipment for two charging-chain systems and a double valve equipment, the latter to be used in connection with stripper foil replacement) and the absence of electrical power in the terminal, required an unusual design for the installation and powering of the new pumps. Technical details of the design as well as some preliminary experience of the use of the new system, especially for accelerator mass spectrometry, will be given. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58978

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

After 23 years of use one of the column supports in the Lund 3 MV electrostatic accelerator broke. Details of the straight-forward and quick replacement work are given. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58979

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

The Vivitron is a large electrostatic accelerator in operation under high voltage since December 1990. Since then, the machine sustained more than 750 sparks and operated more than 17&hthinsp;000 hours at voltages up to 20 MV. The paper presents a review of the electric stresses applied on the insulators of that particular HV generator following the operational experience of the last years. It discusses some of the most recent results related to the electrical stress characterization i.e. calculations and data from bench, factory and field tests. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58942

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

Booster LINACS have matured into an almost standard feature of many accelerator laboratories. Some LINACS are still young and growing, some mature ones prosper through continuous improvement while others require no further development. This overview will present a profile or the current population of booster LINACS. The accomplishments of the laboratories will be surveyed since the last HIAT along with their plans for future development. Those challenges, which the entire HIAT community have in common, will be identified to attract our enthusiasm and inventiveness. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58980

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

10 years after the construction at LNL of its first superconducting resonator, the laboratory has become one of the leading centers in the development of low beta superconducting cavities, including superconducting rfqs. The technologies of bulk niobium, niobium sputtering and lead plating have been used and some of the innovations introduced in the field during the last decade have been developed at LNL. The present technology allows producing cavities that can reach more than 50 MV/m peak surface electric field, both in test cryostats and after installation in the linac. New techniques have been developed to minimize the resonators construction cost, like spinning of multicell cavities, modular design of quarter wave resonators and niobium sputtering on copper: these technologies have reached a high level of performance and reliability. A new technique of mechanical damping was developed for stabilization of large size quarter wave resonators. The lead plating technique was enriched by the stabilization of the lead surface against oxidation. The construction of the first superconducting rfq to be used in an accelerator facility, which required original solutions to the new kind of problems emerging from this project, is at an advanced stage. Recent results obtained at LNL show that the goal of operating superconducting low beta resonators at 8 MV/m in cw mode can be presently reached; future low beta linacs could be designed with an accelerating field which is about two times higher than the one required in the past, with a significant cost reduction that could make these machines affordable also for small laboratories. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58981

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

The JAERI tandem accelerator has been operating effectively since 1982 and heavy ions from the tandem has been boosted in energy by the superconducting independently phased booster linac for the experiments at higher bombarding energies since 1994. Present operating status of the tandem accelerator and its booster, status of their use for experiments and an on-going improvement project with an ECR ion source are described. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58982

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

This work describes the present situation of Pelletron-Linac Project and the steps we have accomplished in the last two years. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58943

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

The tests on the stainless steel prototype for one of the two superconducting RFQs (SRFQs) for PIAVE (SRFQ2), the being built heavy ion injector for the Legnaro booster, were completed in summer 1998, while the construction of the first niobium resonator started in February 1998 and is expected to be completed by April 1999. The structure, resonating at 80 MHz, is 0.8 m long and 0.76 m in diameter. All technological aspects connected with the construction of the SRFQs, and the corresponding tests on the stainless steel model, are reviewed: development of the parts, assembly sequence, electron beam welding (EBW) steps, rough and fine adjustment of the resonant frequency, bead-pull measurements, characterization of the mechanical vibration modes, frequency change due to cooling down and chemical etching tests. The updated development of SRFQ1 is briefly reviewed. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58944

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

The PIAVE superconducting linac is not only made of rfqs; 8 low &bgr; superconducting quarter wave resonators, working at 80 MHz, will give an equivalent acceleration voltage of 7.2 MV; a room temperature triple harmonic buncher working at 40 MHz will match the beam to the rfq input and 2 room temperature, 80 MHz rebunchers will match the beam produced by PIAVE into the linac ALPI. The construction and testing of the first superconducting cavity was more than successful: the resonator, at the design power of 7W, reached 6.3 MV/m corresponding to a total acceleration voltage of 1.13 MV at&bgr;=0.047.This result allowed us to increase the linac design accelerating field from 3 MV/m to 5 MV/m. The 7 remaining superconducting cavities are presently under construction, and they will be completed within 1998. While the more conventional, room temperature 80 MHz rebunchers are at the design stage, the triple harmonic buncher, made of 2 quarter wave resonators, was constructed, tested and it is ready for installation. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58983

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

Superconducting radio-frequency (SRF) cavities have been used to accelerate heavy ion beams for the last quarter century. Over this period devices based on pure lead or a lead-tin alloy electrodeposited on to a copper structure have been a viable alternative to solid niobium cavities, with many comparative advantages such as lower unit cost, ease of re-coating and better thermal stability. We review the historical development, current status and future prospects of the lead-based SRF technology in the context of recent advances in solid and thin-film niobium. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.58970

出版商:AIP    

年代:1999

数据来源: AIP