摘要:

Using a calibrated 3 m grazing incidence spectrometer‐type Romand Vodar equipped with channel plates detector, we studied emission lines in the range between 10 and 100 nm of ions from plasma generated in two different electron cyclotron resonance ion sources (the new CAPRICE and QUADRUMAFIOS). In the VUV range, one can observe many emission lines from nearly all ionization states. From the measurements, performed on oxygen and helium mixture plasmas and thanks to a theoretical model, an estimation is done giving the electronic and ionic densities for different rf powers. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146691

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Characteristic x‐ray lines of heavy ions are used as threshold indicators for the number of plasma electrons with an energy higher than the orbital electron binding energy of the initial vacancy for the corresponding x‐ray transition. For heavy ion plasmas the intensity ratio between x‐ray lines of different series shows how the mean energy of the electron changes with the operating conditions of an electron cyclotron resonance ion source. With the combination of line intensity and bremsstrahlung measurements, information on the anisotropy of the electron energy distribution function is obtained. Characteristic and continuous radiation is recorded at the same time and with the same apparatus. Therefore, errors are extremely small. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146692

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A pinhole camera with an x‐ray sensitive charge‐coupled device array was used to analyze x‐rays emitted from an electron cyclotron resonance (ECR) discharge. The camera was operated at a temperature of 140 K, allowing single photon detection at integration times up to several hours. This technique simultaneously allows spectroscopic investigations as well as x‐ray imaging. Thus, the geometrical size and x‐ray emission profiles from an ECR plasma were measured. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146693

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

This paper deals with a new concept of the full scale ion plasma injector for ECRIPAC—a new supercompact collective action accelerator for ions. The injector has an electron cyclotron resonance (ECR) 10 GHz ‘‘min B’’ quadrupolar magnetic structure which, in contrast to the traditional ECR ion sources, allows the microwaves to penetrate on the periphery of the plasma, and also on the axis of the plasma in conditions close to the first and second Bernstein modes. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146694

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

In this article we describe computer‐based instrumentation to control and optimize the operation of an ion source, and schemes to measure beam properties in low energy beam transport lines. Emphasis is given to the methods used at the accelerator complex of the Paul Scherrer Institute. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146858

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

For many applications of ion sources the quality of the generated ion beam plays an increasingly important role. Ion sources consist of the plasma generator and the extraction system. Both parts can, due to high ion temperature or various aberrations, contribute to a degrading of the beam quality. Though the beam quality is determined by many more factors, the transverse motion of the particles certainly is one of the important parameters. Knowledge of it can be obtained by an emittance measurement. This is best done in a four‐dimensional phase space, yielding a density distribution as function of the transverse spatial and momentum coordinates. Often, however, due to practical considerations, only two dimensions of the four‐dimensional ‘‘trace space’’ are being measured. This two‐dimensional data can be obtained as a section or as a projection of the four‐dimensional trace space, where both methods have their merits. Projectional emittance measurements can usually be performed much easier and quicker, but by the projection of the four‐dimensional space onto a two‐dimensional plane information is lost. And although not all the particles of the beam are represented in a section of trace space, here aberrative distortions of the emittance can be seen most clearly and allow an easier comparison to numerically obtained data. The advantages and disadvantages of both methods are discussed. Numerical and experimental examples are presented. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1147241

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The results of experimental investigations on ion production from tantalum targets, made with the application of the Thomson parabola ion spectrograph (TP) to an image converter equipped with a microchannel plate of the size of 70×90 mm2, are presented. In the experiments, the iodine photodissociation laser system PERUN (&lgr;=1.315 &mgr;m,EL≤50 J, &tgr;∼350–650 ps.I≤1015W/cm2) was used for ion generation. The TP can give useful information about physical processes, ion species, their energies, and charge states from a single laser shot. The results obtained are compared with the results of measurements made with an electrostatic ion energy analyzer and charge collectors and they are used to estimate the Ta ion yield with an average charge state of 40+. The obtained values areN∼2.6×1011sr−1. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146695

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

An on‐line emittance–mass scanner (EMS), with a size of 10 cm×10 cm×8 cm, has been developed for use with low energy and light ion beams (A<40) at TRIUMF. Computerized data acquisition and procession give the rms emittances, intensities, and contour plots of each beam component. The angular resolution of the scanner is ±1.0 mrad, the maximum divergence of each component that the scanner can take is 140 mrad. Some experimental results of the measurement are given. The comparison between the contour shapes and the values of the emittance measured by both the emittance scanner and EMS is in good agreement. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146696

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A workshop on ‘‘Ion Sources for Isotope Separation On Line’’ was held at TRIUMF on September 7–8, 1995. Twenty‐five specialists from France, Russia, Belgium, Switzerland, Germany, Italy, the United States, and Canada and over 15 TRIUMF staff members participated. The workshop was held in conjunction with the sixth international conference on ion sources which took place at Whistler the following week. It is clear that there is no universal ion source for all the elements needed at a radioactive ion beams facility. Very specialized target/ion sources have to be developed for specific elements. The main issues are the release efficiency, the ionization efficiency, and the brightness of the ion source. The major difficulties are the operation in a very hostile environment, high radiation, and high temperature. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146697

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

ISOL–MAFIOS is a high‐efficiency Min B ECRIS charge state breeder for short‐lived ISOL beams in the PIAFE project. The ISOL species issuing from a bombarded target are locally ionized (1+) in a given ion source (ISOLDE type). They are then accelerated, magnetically selected, and transported in a long beam line, before being adequately introduced into ISOL–MAFIOS operating in continuous mode. In this system, an ECR plasma (created with a support gas) replaces the usual solid catcher. The ISOL–MAFIOS system captures the (1+) ions and transforms them into (q+) ions. If we call, overall efficiency of ISOL–MAFIOS the ratio of the beam intensities:I(q+) after the magnetic selector/I(1+) before entering in the source, we find for example for RubidiumIRb9+/IRb1+≊120 enA/1000 enA and a ratio at least two times larger forIKr9+/IKr1+. Moreover, an even more important result of ISOL–MAFIOS is that the release time+ionization time is of the order of 10−2s instead of many seconds for a solid‐state catcher. Thus in the PIAFE project isotopes whose half life times are ≳10−2s become utilizable for acceleration in the two‐cyclotron SARA. Note that in the PIAFE project the (1+) ISOL ions are produced by neutron bombardment of a U target inside the high flux reactor ILL and not by the bombardment of a target by a primary ion beam. ©1996 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146649

出版商:AIP    

年代:1996

数据来源: AIP