Development of the CRIS (Collinear Resonant Ionisation Spectroscopy) beam line

Procter, T.J.; Aghaei-Khozani, H.; Billowes, J.; Bissell, M. L.; Blanc, F. Le; Cheal, B.; Cocolios, T. E.; Flanagan, K.T.; Hori, Hiroshi; Kobayashi, Takayoshi; Lunney, D.; Lynch, K. M.; Marsh, B. A.; Neyens, G.; Papuga, J.; Rajabali, Mustafa; Rothe, S.; Simpson, G. S.; Smith, A. J.; Stroke, H. H.; Vanderheijden, W.; Wendt, Κ.

doi:10.1088/1742-6596/381/1/012070

Cited by 21 publications

(11 citation statements)

References 38 publications

(24 reference statements)

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“…The 206 Fr isotopes of interest were mass selected with the high-resolution mass separator (HRS) and injected into the radio-frequency ISOLDE cooler and buncher, ISCOOL. The bunched ion-beam was extracted at 100 Hz and deflected to the CRIS experimental beam line [26][27][28]. Collisional neutralization with potassium vapor in a hot charge-exchange cell (500 K) was used, and the non-neutralized component of the beam was deflected away.…”

Section: Experimental Techniquementioning

confidence: 99%

Combined high-resolution laser spectroscopy and nuclear decay spectroscopy for the study of the low-lying states inFr206,At202, and
Lynch
¹
,
Cocolios
²
,
Billowes
³

et al. 2016
Phys. Rev. C

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High-resolution laser spectroscopy was performed on 206 Fr with the collinear resonance ionization spectroscopy (CRIS) experiment at CERN-ISOLDE. The hyperfine structure and isotope shift of the ground, first isomeric and second isomeric states were measured. The hyperfine components were unambiguously assigned to each nuclear state by means of laser-assisted nuclear decay spectroscopy. The branching ratios in the α decay of 206 Fr and 202 At were also measured for the first time with isomerically purified beams. The extracted hindrance factors allow determination of the spin of the ground, first isomeric, and second isomeric states in 202 At and 198 Bi.

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Section: Experimental Techniquementioning

confidence: 99%

Combined high-resolution laser spectroscopy and nuclear decay spectroscopy for the study of the low-lying states inFr206,At202, and
Lynch
¹
,
Cocolios
²
,
Billowes
³

et al. 2016
Phys. Rev. C

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“…The trapping time was synchronized with the repetition rate of the Nd:YAG laser (30 Hz) used to ionize the francium atoms. The bunched ion beam was transported from ISCOOL to the CRIS beam line and neutralized in-flight with use of a potassium vapor cell, which was grounded during this experiment [9]. A differential pumping region separates the neutralization cell from the laser-atom interaction region, which was kept at 8 Â 10 À9 mbar to reduce the process of nonresonant collisional ionization.…”

mentioning

confidence: 99%

“…week ending 22 NOVEMBER 2013 0031-9007=13=111(21)=212501 (4) 212501-1 Ó 2013 American Physical Society either a microchannel plate detector [9] or decay spectroscopy station [10]. The phenomenon of shape coexistence in the lead region [11] has been studied recently through charge radii measurements of the neutron deficient lead [12] and polonium isotopes [13,14].…”

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confidence: 99%

Collinear Resonance Ionization Spectroscopy of Neutron-Deficient Francium Isotopes

et al. 2013

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The magnetic moments and isotope shifts of the neutron-deficient francium isotopes [202][203][204][205] Fr were measured at ISOLDE-CERN with use of collinear resonance ionization spectroscopy. A production-todetection efficiency of 1% was measured for 202 Fr. The background from nonresonant and collisional ionization was maintained below one ion in 10 5 beam particles. There are surprisingly few nuclear observables with which theorists can elucidate the nuclear force and interacting many-fermion problem. The laser spectroscopy technique reported here has measured two of these (the magnetic moment and mean-square charge radius) via the hyperfine interaction and isotope shift. This is achieved without introducing assumptions associated with any particular approach, making these measurements suitable for testing modern nuclear models. A variety of laser spectroscopy techniques now exists for studying shortlived radioactive isotopes, which broadly focus on either high resolution (< 100 MHz linewidth) or high sensitivity (< 1 atom=s) [1,2].We report here the first measurements of 202;203;205 Fr, reaching 11 neutrons from the N ¼ 126 shell closure. This has been made possible by a new highly sensitive, highresolution technique of bunched collinear-beam resonance ionization spectroscopy (CRIS). The CRIS technique combines for the first time velocity bunching (provided by the collinear geometry [3,4]) and time bunching (to eliminate the duty loss of required pulsed laser systems). The high sensitivity is reached through a combination of the excellent overlap of laser and beam, and the high quantum efficiency of ion detectors. This new technique may be applied generally to all nuclides, but it is at the limits of nuclear stability that it will manifest its particular advantages.The CRIS method was first proposed more than 30 years ago [5], and its sub-Doppler resolution was demonstrated by Schultz et al., who measured the radioactive isotopes of ytterbium [6]. Since these isotopes were produced as a continuous beam, the duty cycle losses associated with pulsed lasers introduced a loss in efficiency by a factor of 30, which contributed to a low total experimental efficiency of 0.001%. With the installation of a gas-filled radio frequency quadrupole ion trap (ISCOOL) at ISOLDE, bunched ion beams that match the duty cycle of the pulsed lasers are now available [7]. This motivated the development of a dedicated experiment to exploit the CRIS technique applied to time-bunched beams. In the present case it allowed for the first time measurements of the neutrondeficient francium isotopes with half-lives as short as 300 ms and production rates below 100 atoms=s.In our work the francium isotopes were produced through spallation reactions induced by 1.4 GeV protons, incident on a high temperature uranium carbide target (2000 C) and surface ionized (ionization potential 4.07 eV [8]) with use of a tantalum ionizer tube. A schematic of the experiment is presented in Fig. 1. The beam was accelerated to 50 keV, mass separated, and sub...

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“…The heart of the CRIS setup [4,5] is the interaction region, held at < 10 −8 mbar, where the collinear resonance ionization process occurs, see Fig. 1.…”

Section: The Cris Experimentsmentioning

confidence: 99%

Achieving sensitive, high-resolution laser spectroscopy at CRIS

Groote¹,

Lynch

Wilkins

2016

Hyperfine Interact

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The Collinear Resonance Ionization Spectroscopy (CRIS) experiment, located at the ISOLDE facility, has recently performed high-resolution laser spectroscopy, with linewidths down to 20 MHz. In this article, we present the modifications to the beam line and the newly-installed laser systems that have made sensitive, high-resolution measurements possible. Highlights of recent experimental campaigns are presented.

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Development of the CRIS (Collinear Resonant Ionisation Spectroscopy) beam line

Cited by 21 publications

References 38 publications

Combined high-resolution laser spectroscopy and nuclear decay spectroscopy for the study of the low-lying states inFr206,At202, and
Lynch
¹
,
Cocolios
²
,
Billowes
³

et al. 2016
Phys. Rev. C

Combined high-resolution laser spectroscopy and nuclear decay spectroscopy for the study of the low-lying states inFr206,At202, and
Lynch
¹
,
Cocolios
²
,
Billowes
³

et al. 2016
Phys. Rev. C

Collinear Resonance Ionization Spectroscopy of Neutron-Deficient Francium Isotopes

Achieving sensitive, high-resolution laser spectroscopy at CRIS

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Development of the CRIS (Collinear Resonant Ionisation Spectroscopy) beam line

Cited by 21 publications

References 38 publications

Combined high-resolution laser spectroscopy and nuclear decay spectroscopy for the study of the low-lying states inFr206,At202, andLynch1, Cocolios2, Billowes3 et al. 2016Phys. Rev. C

Combined high-resolution laser spectroscopy and nuclear decay spectroscopy for the study of the low-lying states inFr206,At202, andLynch1, Cocolios2, Billowes3 et al. 2016Phys. Rev. C

Collinear Resonance Ionization Spectroscopy of Neutron-Deficient Francium Isotopes

Achieving sensitive, high-resolution laser spectroscopy at CRIS

Contact Info

Product

Resources

About

Combined high-resolution laser spectroscopy and nuclear decay spectroscopy for the study of the low-lying states inFr206,At202, and
Lynch
¹
,
Cocolios
²
,
Billowes
³

et al. 2016
Phys. Rev. C

Combined high-resolution laser spectroscopy and nuclear decay spectroscopy for the study of the low-lying states inFr206,At202, and
Lynch
¹
,
Cocolios
²
,
Billowes
³

et al. 2016
Phys. Rev. C