Laser-plasma Ion Source Research Articles

Laser plasma ion source for intense heavy ion beams (abstract)

In a series of experiments a laser plasma ion source for TA ions has been investigated. The main components were a 3-J CO2 laser, the laser ion source, a 3.2-m beamline, a 90° analyzing magnet, and an ion detector. The FWHM of the CO2 laser pulse was approximately 100 ns, the full duration was about 1 μs. The spot diameter was about 0.2 mm. The charge state distribution has been measured up to 10+. The plasma temperature has been calculated; recombination has been observed. The results will be shown and discussed in detail.

Pulsed ion beams for modification of metal surface properties

A versatile technique using pulsed laser-plasma ion source (PLPIS) was developed for various ion beam treatments of materials (ion implantation, ion beam mixing, and ion beam assisted deposition).

Study of the ion-optical properties of the mass spectrometer Lidia

The ion-optical characteristics of the ultrasensitive mass spectrometer LIDIA designed to search for superheavy elements ( A > 250) with a sensitivity of up to 10 −14 at./at. using a laser plasma ion source and a multistage separation system have been calculated. The main ones (acceptance, momentum dispersion, resolution and line shape) have been measured by means of 249Cf and 226Ra α-particle beams. A good agreement of the obtained results with the calculated ones is shown. The mass spectrometer is made operational with a laser plasma ion source. This will enable one to carry out the mass-spectrometric analyses of natural samples with fairly high utilization of the specimen material (10 −6–10 −3) and wish a resolution sufficient to resolve the mass lines of the superheavy elements searched.

Trace element analysis by laser plasma mass spectrometry

A double focusing mass spectrometer was equipped with a laser plasma ion source. This instrument has been used for multi-element analysis of solid materials. Laser plasma mass spectrometry (LMS) permits direct analysis of both conducting and non-conducting samples. The abundances of about 30 trace elements can be determined simultaneously in rock samples. A great advantage of LMS is that most elements are ionized with about the same efficiency, this means that only small corrections are necessary for quantitative analysis. Solutions which have been dried on a quartz disk can also be analyzed. This technique yields mass spectra which are free of interferences of molecules or cluster-ions.

Screening action of a crater in local and layer-by-layer analysis in a mass spectrograph with a laser-plasma ion source

It is shown that materials with different physical properties are characterized by different widths of the linear part of the dependence of the charge reaching the slit of a mass-spectrograph monitor on the number of laser pulses. This difference and the change in the ratio of singly and doubly charged ions in the analytic part of a mass spectrograph are determined by the shape of the craters formed as a result of the interaction of laser radiation with the investigated material.

Neutron generation in a sealed direct-acceleration tube with a laser-plasma anode

Experiments have been performed on neutron generation in small sealed tubes with laser-plasma ion sources. The nuclear reaction T(d, n)He4 has been employed with a laser frequency of 12.5 Hz in producing an output of 5 · 109 n/sec. It is shown that efficient neutron generation is possible for laser pulse energies at the 10−2 J level.