摘要:

The production of radioactive ion beams in the SPIRAL project requires very efficient ion sources delivering beams with good optical properties. To improve these properties, the extraction conditions are under study. This paper will present the last results obtained with a new extraction system and will compare them to a numerical simulation. This comparison shows that the axial magnetic field influences the multicharged ion beam if the space charge during the acceleration is not compensated. In order to decrease the axial magnetic field effect on the extraction zone, a parallel beam can be formed with a multielectrode system. The first tests of this system will be presented. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146662

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A rf ion source is presently being developed and evaluated as a potential candidate for use in generating radioactive ion beams (RIBs) for the experimental research program at the Holifield Radioactive Ion Beam Facility (HRIBF) now under construction at the Oak Ridge National Laboratory. For this application, any time delays that are excessively long with respect to the half‐life of the radioactive species of interest can result in significant losses of the RIB intensity; therefore the times for effusive flow through the ion source are of fundamental importance since they set limits on the minimum half‐life of radioactive species that can be processed in the source. Complementary experimental and computational techniques have been developed which can be used to determine the characteristic delay times for gaseous species in low‐pressure ion source assemblies. These techniques are used to characterize the effusive delay times for the stable counterparts of various atomic and molecular radioactive species in the ORNL‐rf source: He, Ne, Ar, Kr, Xe, H2, CO, CO2, N2, N2O, and O2. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1147245

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A Stern–Gerlach polarized ion source for intense polarized H and D beams is under construction at the Munich tandem accelerator laboratory. The goal is to achieve negative beams of about 2 &mgr;A on target with excellent brightness. This development goes in parallel with our collaboration at the HERMES ABS and compatibility between both systems is strived for. Intensity tests of electron polarized H beams just started. A flux of 4×1016H/s was observed so far in preliminary tests. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146663

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The duoplasmatron source was specially designed as a component of the hydrogen and deuterium negative polarized ion source, of Lamb–Shift type, for equipping the FN–Tandem Accelerator in Bucharest. The source can operate long‐term at an arc power of 2.5 kW with an intensity of the arc current of 10–11 A. The duoplasmatron source anode is of a special construction in order to allow a strong cooling and a quick adaptation of some cups for the plasma expansion. Three variants of the extraction ion‐optics configuration have been analyzed by computer and then experimentally carried out and tested. All the extraction ion‐optics configurations employ plasma expansion cups and the process of deacceleration of the beam down to energies of 500–1000 eV is taking place inside of a magnetic lens. The proton and deuterium beam intensity obtained beyond the magnetic lens may exceed 10 mA, function of the discharge conditions in the arc and the ion‐optics configuration employed. The ion composition of the beam (H1, H2, H3) function of the discharge parameters in the arc, has also been analyzed and the results showed that the percentage of the atomic ions is higher than 70%. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146664

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The polarized ion source for COSY‐Ju¨lich has been set in operation. The source producesH−orD−ion beams by means of a charge exchange reaction. For the first time beam acceleration in the injector cyclotron and a first measurement of the beam polarization downstream of the cyclotron took place. The working scheme of this colliding‐beam source and the latest results are discussed. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146665

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Results are presented of a pulsed optically pumped polarized H−ion source development for high energy accelerators. An atomic hydrogen beam intensity of 2×1018atoms/s within the polarizer acceptance was obtained with an atomic H injector at BINP. A pulsed polarized H−ion current of about 10–20 mA should be obtainable using this injector. Limitations on beam characteristics due to space charge were studied. A polarization scheme to avoid space charge limitations is considered, in which charge exchange and spin exchange are combined. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146666

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

To obtain a highly nuclear‐spin vector polarized negative deuterium ion beam, a dual optically pumped polarized negative deuterium ion source has been developed at KEK. It is possible to select a pure nuclear‐spin state with this scheme, and a negative deuterium ion beam with 100% nuclear‐spin vector polarization can be produced in principle. Thus far, we have obtained about 70% of the nuclear‐spin vector polarized negative deuterium ion beam. This result may open up new possibilities for the optically pumped polarized ion source. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146667

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A new design of a broad beam rf ion source is made to deliver currents of 100 &mgr;A–30 mA with extraction voltages of 200 V–2 kV. Its plasma intensifying system is made with both the addition of electrons from an immersed filament in the discharge and an axial magnetic field of 70–300 G. Uniform beam density distribution is made with a planner graphite cathode which has a number of holes of varying diameters arranged to produce perveance matching with the normal Gaussian distribution of the beam density. Variations of the output currents are studied with variations of extraction voltage, magnetic field intensity, discharge pressure, and electron injection into the plasma. The influence of electron injection into the plasma is found to have a great effect on increasing the extracted current to about four times its value without electron injection. The increase of extraction voltage is limited to the use of electron injection atVex≳2 kV due to the presence of breakdown inside the discharge tube. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146668

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

In cooperation with CEN‐Grenoble we developed a high temperature oven for the production of beams from rare and expensive nickel isotopes (62Ni and64Ni) with an electron cyclotron resonance (ECR) ion source Caprice‐14 GHz. For the first time, nickel has been produced in this way. For an experiment at the Unilac we have provided a stable Ni9+beam for 40 days with a mean intensity of 25e&mgr;A. The nickel consumption was a few mg per hour and ten ovens have been used for that period. Surprising and promising results were obtained with this oven for the production of uranium beams by using UO2samples. These results are compared with the ‘‘plasma heating’’ method. Complementary investigations about the already studied ‘‘sputtering’’ method are also presented. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146669

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

This article describes studies performed on the National Superconducting Cyclotron Laboratory’s Superconducting‐ECR (electron cyclotron resonance) ion source for the production of metallic ion beams. The Room Temperature‐ECR ion source as the workhorse for generating metallic ion beams using a solid feed system will be superceded in the future by the Superconducting‐ECR ion source. A series of tests were carried out with a Langmuir probe introduced axially into the plasma chamber of the Superconducting‐ECR ion source. These tests determined the location and shape of the plasma and its floating potential. The results presented show the effect of source bias and axial magnetic field on the plasma boundary. Some preliminary results for gold sputtering are also included. The use of a solid metal, saturated in deuterium, to produce deuterium beams in the Room Temperature‐ECR ion source has also been studied. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146670

出版商:AIP    

年代:1996

数据来源: AIP