摘要:

A multi‐sampleCs‐sputter negative ion source has been evaluated for generating7BeO−beams for measuring the nuclear‐astrophysically important7Be(p,&ggr;)8Breaction at the Holifield Radioactive Ion Beam Facility. The design features and operational parameters of the source are described and measured efficiencies for forming beams ofNi−,C−andMgO−and estimated efficiencies for generating beams ofBeO−for the proposed experiment are presented in this report. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619881

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Some of the new instruments and devices recently commissioned at the Wright Nuclear Structure Laboratory (WNSL) are described and the physics programs carried out using them are outlined. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619882

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Bright, RF photocathode electron guns are the source of choice for most high‐performance research accelerator applications. Some of these applications are pushing the performance boundaries of the present state‐of‐the‐art guns. Advanced Energy Systems is developing a novel photocathode RF gun that shows excellent promise for extending gun performance. Initial gun simulations with only a short booster accelerator easily break the benchmark emittance of one micron for 1 nC of bunch charge. The pulse length in these simulations is less than 2 ps. It is expected that with more detailed optimization studies, the performance can be further improved. The performance details of the gun will be presented. In addition, we will discuss the present design concept along with the status of the project. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619883

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The ECRIS‐Facility at the Ionenstrahllabor ISL (ion beam laboratory) consists of a 14.5 GHz‐ECR‐source, a potential‐variable beamline system and four target areas. It is dedicated to produce ions from H to Xe with charge states from 1 ⩽ q ⩽ 27, in an ion energy range from ∼1 eV to ∼450 keV depending on the effective acceleration potential up to 17 kV. To enable a user‐friendly operation of the facility, especially for guest groups, the control system CODIAN was developed. The CODIAN‐system accesses and protocols all parameters in the various hardware set‐up, saving and restoring the complete settings of all beamline components. The flexibility of the software concept and the wide range of hardware implementations will be demonstrated. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619884

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

In the work reported, the possibility of using a nested Penning trap as a high purity source of low‐charge‐state ions is studied. For the configuration considered, a relatively dense ion plasma is confined by a three‐dimensional electric potential well. The three‐dimensional well is produced by the electric field generated by both the trap electrodes and a trapped electron plasma. The ion and electron plasmas are each considered to have Maxwellian velocity distributions. However, it is shown that the electron plasma must have a temperature that is higher than that of the ion plasma when the ions have low charge states. The work reported includes a self‐consistent prediction of a possible plasma equilibrium. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619885

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Existing spallation neutron source upgrades, planned spallation neutron sources, and high‐energy accelerators for particle physics place demanding requirements on the H−sources. These requirements ask for increased beam currents and duty factor (df) while generally maintaining state‐of‐the art H−source emittance. A variety of H−sources are being developed to address these challenges. These include volume sources with and without the addition of cesium for enhanced H−production, increased df cesiated H−Penning and magnetron sources, and cesiated surface converter H−sources. Research on surface films of tantalum metal for enhanced volume H−production is also being studied. Innovative plasma production techniques to address the longer df requirement without sacrificing H−source reliability and lifetime will be reviewed. The physical bases, the goals, and perceived challenges will be discussed. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619886

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

As computer technology plays an increasing important role in particle accelerator facilities, instrumentation systems can be expected to include web connections and other remote capability features. The Michigan Ion Beam Laboratory at the University of Michigan in Ann Arbor has developed remote monitor and control capability by using a combination of commercial software packages and in‐house software development. Irradiation parameters such as ion current on the samples and apertures, sample temperature read from an optical pyrometer, and chamber pressure can all be accessed and monitored remotely through a web site, as can ion source parameters such as power supply currents and voltages or feed gas pressure. With administrator permission, the control parameters of the ion source or the readouts from the irradiation stage can be modified in real time during an experiment. A description will be given of the various ways in which this type of remote monitoring and control has been accomplished at the Michigan Ion Beam Laboratory. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619887

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The Low Energy Beam and Ion Trap (LEBIT) Project aims to convert the high‐energy exotic beams produced at NSCL/MSU into low‐energy low‐emittance beams. A combination of a high‐pressure gas stopping cell and a radiofrequency quadrupole (RFQ) ion accumulator and buncher will be used to manipulate the beam accordingly. High‐accuracy mass measurements on very short‐lived isotopes with a 9.4 T Penning trap system will be the first experimental program to profit from the low‐energy beams. The status of the project is presented with a focus on recent stopping tests of 100–140 MeV/A Ar18+ions in a gas cell. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619888

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

There has been a lot of interest in compact sources of high brightness, relativistic electron beams. One approach for developing such a source is to apply a high gradient that remains constant during the generation and acceleration of the electron beam. In this paper, we describe high voltage pulse generators that deliver up to 5 MV with 1 ns pulse duration. These devices are synchronizable to an external trigger with jitter of ∼ 0.5 ns and can establish gradients in excess of 1 GV/m between two electrodes without breakdown. In the presence of field gradients up to 0.5 GV/m, electron beams of bunch lengths ranging from 1 ns to 0.3 ps and diameter < 300 &mgr;m have been generated by irradiating the cathode with UV lasers. Characteristics of these electron beams as well as those produced via field emission at gradients up to 1 GV/m will be discussed. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619889

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

A 6 GHz, all‐permanent magnet, “volume‐type” Electron Cyclotron Resonance (ECR) ion source has been initially tested at the Oak Ridge National Laboratory. The source has the following design properties: (1) an Al plasma chamber; (2) a mechanically adjustable, flat‐bottomed mirror magnetic field distribution tuned to the ECR condition; (3) a dodecapole cusp‐magnet for radial plasma confinement; (4) a Right‐Hand‐Circularly‐Polarized (RHCP) traveling wave RF injection system, (5) a movable three‐electrode extraction system, and (6) facility for conversion into a conventional minimum‐B magnetic field “surface” source configuration. Details of the source design, magnetic field distribution, operational parameters and initial results derived from first operation of the source (e.g., charge state spectra and intensity distributions for a given charge state) are provided for argon. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619890

出版商:AIP    

年代:1903

数据来源: AIP