A gas cell for thermalizing, storing and transporting radioactive ions and atoms. Part II: On-line studies with a laser ion source

For the production of radioactive ion beams by means of the ISOL (isotope separation on-line) method in which the nuclei of interest are stopped in a thick target, chemistry plays a crucial role. It serves to separate the nuclear reaction products in atomic or molecular form from the bulk target and to transfer them efficiently to an ion source. This article gives an overview of ISOLDE radiochemical methods where targets (liquid metals, solid metals, carbides and oxides) and ion sources are optimized with respect to efficiency, speed and chemical selectivity. Rather pure beams of non-metals and volatile metals can be obtained with a temperature-controlled transfer line acting as thermo-chromatograph. For less volatile metals the temperature of the target and ion source units needs to be kept as high as possible, but a selective ion source can be used: positive surface ionization for metals with ionization potentials below about 6 eV and the RILIS (resonance ionization laser ion source) technique for most other metals.

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Developments towards the delivery of selenium ion beams at ISOLDE

The European Physical Journal A ◽

10.1140/epja/i2019-12873-4 ◽

2019 ◽

Vol 55 (10) ◽

Cited By ~ 1

Author(s):

K. Chrysalidis ◽

J. Ballof ◽

Ch. E. Düllmann ◽

V. N. Fedosseev ◽

C. Granados ◽

...

Keyword(s):

Maximum Yield ◽

Target Material ◽

Ion Beams ◽

Ion Source ◽

Resonance Ionization ◽

Laser Ion Source ◽

On Line ◽

Ionization Scheme ◽

Ionization Methods ◽

Resonance Laser

Abstract. The production of selenium ion beams has been investigated at the CERN-ISOLDE facility via two different ionization methods. Whilst molecular selenium (SeCO) beams were produced at ISOLDE since the early 1990s, recent attempts at reliably reproducing these results have so far been unsuccessful. Here we report on tests of a step-wise resonance laser ionization scheme for atomic selenium using the ISOLDE Resonance Ionization Laser Ion Source (RILIS). For stable selenium an ionization efficiency of 1% was achieved. During the first on-line radioisotope production tests, a yield of $ \approx 2.4 \times 10^4$≈2.4×104 ions/μC was measured for 71Se+, using a ZrO2 target with an electron impact ion source. In parallel, an approach for extraction of molecular carbonyl selenide (SeCO) beams was tested. The same ion source and target material were used and a maximum yield of $ \approx 3.6\times 10^5$≈3.6×105 ions/μ C of 71SeCO+ was measured.

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Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for high-energy RI beams in the parasitic gas cell

Progress of Theoretical and Experimental Physics ◽

10.1093/ptep/ptz120 ◽

2019 ◽

Vol 2019 (11) ◽

Author(s):

T Sonoda ◽

I Katayama ◽

M Wada ◽

H Iimura ◽

V Sonnenschein ◽

...

Keyword(s):

High Energy ◽

Ion Source ◽

Low Energy ◽

Laser Ion Source ◽

Gas Cell ◽

Beam Production ◽

Expected Benefits ◽

Conceptual Study ◽

Ri Beam

Abstract An in-flight separator performs the important role of separating a single specific radioactive isotope (RI) beam from the thousands of RI beams produced by in-flight fission as well as projectile fragmentation. However, when looking at ``separation'' from a different viewpoint, more than 99% of simultaneously produced RI beams are just eliminated in the focal plane slits or elsewhere in the separator. In order to enhance the effective usability of the RIKEN in-flight separator BigRIPS, we have been developing an innovative method: parasitic laser ion source (PALIS), which implements parasitic low-energy RI beam production by saving eliminated RI beams during BigRIPS experiments. In this paper, we present the expected benefits and feasibility for the PALIS concept and the results of the first stopping examination for high-energy RI beams in the gas cell.

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