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Selected publications

The "IGISOL Portrait - three decades of research" is a collection of articles describing the research conducted using the ion guide technique at IGISOL.

Ion traps in nuclear physics—Recent results and achievements. T. Eronen, A. Kankainen, and J. Äystö, Progress in Particle and Nuclear Physics 91, 259-293 (2016).

Laser spectroscopy for nuclear structure physics. P. Campbell, I.D. Moore and M.R. Pearson, Progress in Particle and Nuclear Physics 86, 127-180 (2016)

Weak interaction studies

Weak interaction is one of the four known fundamental interactions of nature. It is, for example, responsible for nuclear beta decay process, where proton is transformed to neutron or vice versa in the nucleus of an atom. At the same time also a positron and a neutrino (or electron and an anti-neutrino) is emitted. The energy released in the decay is distributed between the three particles -- each time in differently, underlying the challenges in studying beta decay.

The amount of energy released in the decay (also known as the Q-value) is one of the key quantities in these studies. Recently, through advances in atomic mass spectrometry, the most precise way of measuring a Q-value is through a mass difference measurement of the decay-parent and daughters. The energy is obtained using the mass-energy equivalence formula E=mc², where E is the decay energy, m the mass difference and c the speed of light.

Optical spectroscopy

The structure and properties of atomic nuclei can be measured using many different techniques. One important class of techniques uses lasers to probe the energy levels of the electrons which are bound to the nucleus, in order to access the electromagnetic nuclear moments, the nuclear spin, and the changes in the size of the nucleus. These observables provide unique insight into the configuration of atomic nuclei, the purity of their wavefunctions, their shape and deformation and their nuclear sizes. Thus, they are exceptionally potent tests for nuclear models.

Optical spectroscopy techniques yield very precise values for these nuclear observables and can be applied even to short-lived isotopes produced with relatively low production rates. At the IGISOL laboratory, we currently have three experimental laser spectroscopy stations which offer a different compromise between experimental efficiency and resolution.

In addition to these spectroscopy experiments, we also house two experiments which rely on lasers to manipulate the properties of atoms or ions placed inside of traps. The aim of these projects is to look for physics beyond the standard model through precision beta-decay studies (MORA), and to realize the first experimental demonstration of gamma-ray coherent emission by means of super-radiance in a Bose-Einstein condensate of 135mCs isomers (GAMMALAS).

The IGISOL (Ion Guide Isotope Separation On-Line) mass separator is the heart of the research infrastructure of the  -group. The facility is located in the newer part of the JYFL Accelerator Laboratory built around 10 years ago. IGISOL produces a broad range of low-energy (30 keV) radioactive and stable ion beams for studies of atomic nuclei and their properties. 

Ion guides

The radioactive ions are produced with different kinds of techniques at the IGISOL (Ion Guide Isotope Separator On-Line) facility. We do active research and development work related to the ion guide method, gas cells and related production techniques.

The IGISOL method is fast, sub-ms technique for producing low-energy radioactive ion beams. It was developed in Jyväskylä in early 1980s. The IGISOL technique is chemically insensitive, and thus makes it possible to produce radioactive beams of all elements, including refractory elements usually difficult to produce at ISOL facilities. The basic idea, stopping of ions in gas with a swift extraction of radioactive ion beams, has been adopted in many major accelerator facilities worldwide over the years.

For example the following ion guides or ion sources have been used or developed at IGISOL:

• Light-ion ion guide for fusion-evaporation reactions with p or d beams
• Heavy-ion ion guide HIGISOL for heavy ion fusion-evaporation reactions
• Fission ion guide for proton- or deuteron-induced fission
• Fission ion guide designed for neutron-induced fission
• Ion guide for multinucleon-transfer reactions
• Hot cavity laser ion source 

• Off-line ion source station for stable ion beams

  References to main publications describing the technique

• 
  Hyperfine Interactions 223, 17 (2014). [Open Access: ]
  I. D. Moore, P. Dendooven, J. Ärje
• 
  Nuclear Instruments and Methods in Physics Research B 222 (2004) 632
  J. Huikari et al.
• 
  Nuclear Physics A 693 (2001) 477–494
  J. Äystö
• 
  Review of Scientific Instruments 86, 123501 (2015)
  M. Reponen et al.
• 
  Nuclear Instruments and Methods in Physics Research B 376, 46 (2016). 
  [Open Access: ]
  D. Gorelov et al.
• 
  European Physical Journal A 51, 59 (2015). [Open Access: ]
  A. Al-Adili et al.
• 
  Nuclear Instruments and Methods in Physics Research Section A 263, 382-383 (2020).
  [Open Access: ]
  M. Vilen et al.

Radio-Frequency Quadrupole (RFQ) Cooler and Buncher

The RFQ cooler and buncher cools the ions and converts the continuous radioactive ion beam into narrow ion bunches. The ejected bunches are further used in different kinds of ion trapping and laser spectroscopy experiments. The RFQ cooler and buncher was developed and commissioned at IGISOL already in early 2000s. Details can be found from:

1. V. Virtanen et al., Nucl. Instrum. Meth. Phys. Res. A 1072 (2025) 170186
   
    
2. A. Nieminen et al., Nucl. Instrum. Meth. Phys. Res. A 469 (2001) 244
   
    
3. A. Nieminen et al., Phys. Rev. Lett. 88 (2002) 094801
   

A new cooler-buncher for has also been designed, constructed and commissioned at IGISOL:

• A. Jaries et al., Nucl. Instrum. Meth. Phys. Res. A 1073 (2025) 170273