Optimising the Collinear Resonance Ionisation Spectroscopy (CRIS) experiment at CERN-ISOLDE

Vernon, A. R.; Groote, R. P. de; Billowes, J.; Binnersley, C. L.; Cocolios, T. E.; Farooq-Smith, G. J.; Flanagan, Kieran; Ruiz, R. F. Garcia; Gins, W.; Koszorús, Á.; Neyens, G.; Ricketts, C. M.; Smith, A. J.; Wilkins, S. G.; Yang, Xiaofei

doi:10.1016/j.nimb.2019.04.049

Cited by 19 publications

(21 citation statements)

References 42 publications

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“…In + ions were produced using an ablation ion source (detailed in Refs. 31,42 ), with a pulsed 532-nm Litron LPY 601 50-100 PIV Nd:YAG laser focused to produce a fluence of >0.5 J/cm 2 on a solid indium target (99% purity).…”

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confidence: 99%

Heterogeneity of Outcome Measures Used in Randomized Controlled Trials for the Treatment of Oral Lichen Planus: A Methodological Study

Yan

Hua

et al. 2020

Journal of Evidence Based Dental Practice

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This work reports on the application of a novel electric field-ionization setup for high-resolution laser spectroscopy measurements on bunched fast atomic beams in a collinear geometry. In combination with multi-step resonant excitation to Rydberg states using pulsed lasers, the field ionization technique demonstrates increased sensitivity for isotope separation and measurement of atomic parameters over previous non-resonant laser ionization methods. The setup was tested at the Collinear Resonance Ionization Spectroscopy experiment at ISOLDE-CERN to perform high-resolution measurements of transitions in the indium atom from the 5s 2 5d 2 D 5/2 and 5s 2 5d 2 D 3/2 states to 5s 2 np 2 P and 5s 2 nf 2 F Rydberg states, up to a principal quantum number of n = 72. The extracted Rydberg level energies were used to re-evaluate the ionization potential of the indium atom to be 46,670.107(4) cm −1 . The nuclear magnetic dipole and nuclear electric quadrupole hyperfine structure constants and level isotope shifts of the 5s 2 5d 2 D 5/2 and 5s 2 5d 2 D 3/2 states were determined for 113,115 In. The results are compared to calculations using relativistic coupled-cluster theory. A good agreement is found with the ionization potential and isotope shifts, while disagreement of hyperfine structure constants indicates an increased importance of electron correlations in these excited atomic states. With the aim of further increasing the detection sensitivity for measurements on exotic isotopes, a systematic study of the field-ionization arrangement implemented in the work was performed at the same time and an improved design was simulated and is presented. The improved design offers increased background suppression independent of the distance from field ionization to ion detection.were not resonantly excited, allowing ion detection measurements with significantly reduced background. The experiment has so far reached a background suppression factor of 2.5 × 10 8 providing a detection sensitivity down to yields of around 20 atoms per second 25 . The main source of ion background for the technique is due to collisional re-ionization of the atom beam (often also containing a substantial amount of isobaric contamination) with residual gas atoms along the collinear laser overlap volume. For this reason, considerable effort is given to reach ultra-high vacuum pressures (<1 × 10 −9 mbar) in this laser-atom interaction region. The work reported here demonstrates that the incorporation of field ionization, previously tested on continuous atom beams [26][27][28] , can further increase the sensitivity of measurements on bunched atomic beams by also compressing the measurements into a narrow ionization volume. In addition, we show the approach has advantages for measurements of atomic parameters when combined with the multi-step pulsed narrow-band laser excitation. The sensitivity of the approach is further improved by removing the need for a powerful non-resonant laser ionization step, which often contributes substantially to the re-ionizati...

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mentioning

confidence: 99%

Heterogeneity of Outcome Measures Used in Randomized Controlled Trials for the Treatment of Oral Lichen Planus: A Methodological Study

Yan

Hua

et al. 2020

Journal of Evidence Based Dental Practice

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“…The use of ion cooling and bunching has allowed highly sensitive measurements of exotic atoms and molecules containing short-lived isotopes to date 1 , 3 , by concentrating measurements on ion bunches into a narrow time window, in order to improve background suppression and additionally allowing a high duty cycle for high-resolution and high-detection efficiency pulsed laser ionization spectroscopy 20 , 42 , 43 .…”

Section: Discussionmentioning

confidence: 99%

“…Spatial alignment of the atom and ion paths was performed using irises and Faraday cups. The ion beam waist was measured to be around 3(1) mm using an iris 42 , below this a reduction in beam current begin to be observed. This was measured 30 cm from the neutralisation cell.…”

Section: Methodsmentioning

confidence: 96%

“…The measurements reported here were performed following a modification of the CRIS experimental setup 42 , 43 . A schematic layout of the modified setup is shown in Fig.…”

Section: Methodsmentioning

confidence: 99%

“…In ions were produced using an ablation ion source (detailed in Refs. 31 , 42 ), with a pulsed 532-nm Litron LPY 601 50-100 PIV Nd:YAG laser focused to produce a fluence of >0.5 J/cm on a solid indium target (99% purity).

Figure 1 ( a ) A schematic diagram of the layout of the modified CRIS experiment, to use field ionization.…”

Section: Methodsmentioning

confidence: 99%

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Laser spectroscopy of indium Rydberg atom bunches by electric field ionization

Vernon

Ricketts

Billowes

et al. 2020

Sci Rep

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This work reports on the application of a novel electric field-ionization setup for high-resolution laser spectroscopy measurements on bunched fast atomic beams in a collinear geometry. in combination with multi-step resonant excitation to Rydberg states using pulsed lasers, the field ionization technique demonstrates increased sensitivity for isotope separation and measurement of atomic parameters over previous non-resonant laser ionization methods. The setup was tested at the Collinear Resonance Ionization Spectroscopy experiment at ISOLDE-CERN to perform highresolution measurements of transitions in the indium atom from the 5s 2 5d 2 D 5/2 and 5s 2 5d 2 D 3/2 states to 5s 2 np 2 p and 5s 2 nf 2 F Rydberg states, up to a principal quantum number of n = 72. The extracted Rydberg level energies were used to re-evaluate the ionization potential of the indium atom to be 46, 670.107(4) cm −1. The nuclear magnetic dipole and nuclear electric quadrupole hyperfine structure constants and level isotope shifts of the 5s 2 5d 2 D 5/2 and 5s 2 5d 2 D 3/2 states were determined for 113,115 In. The results are compared to calculations using relativistic coupled-cluster theory. A good agreement is found with the ionization potential and isotope shifts, while disagreement of hyperfine structure constants indicates an increased importance of electron correlations in these excited atomic states. With the aim of further increasing the detection sensitivity for measurements on exotic isotopes, a systematic study of the field-ionization arrangement implemented in the work was performed at the same time and an improved design was simulated and is presented. the improved design offers increased background suppression independent of the distance from field ionization to ion detection. The ability to separate and study small quantities of isotopes from a large ensemble without losses is the limiting factor of many experimental studies in modern nuclear physics 1-4 , as exotic isotopes of interest can often only be produced at low rates (fewer than 100s of ions per second) and their accumulation into substantial quantities is prevented by their short half-lives. Furthermore, sensitive detection or separation of small quantities of isotopes also has numerous technological applications 5-11. Fast beam collinear laser spectroscopy techniques have allowed high-precision measurements on short-lived isotopes, down to rates of fewer than 100 ions per second 3,12,13. These approaches use the Doppler compression of an accelerated atomic beam to enable high-precision laser spectroscopy measurements to be performed in a collinear geometry 14,15. This technique is now being implemented at radioactive ion beam facilities worldwide, giving a resolution of a few 10s of MHz, which is sufficient to resolve the hyperfine structure for nuclear physics studies 16-19. Motivated by a need for higher sensitivity to access exotic isotopes produced at rates lower than a few ions per second, a variation of the technique, the Collinear Resonance Ionization Spectr...

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A direct diode pumped Ti:sapphire laser with single-frequency operation for high resolution spectroscopy

et al. 2020

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Optimising the Collinear Resonance Ionisation Spectroscopy (CRIS) experiment at CERN-ISOLDE

Cited by 19 publications

References 42 publications

Heterogeneity of Outcome Measures Used in Randomized Controlled Trials for the Treatment of Oral Lichen Planus: A Methodological Study

Heterogeneity of Outcome Measures Used in Randomized Controlled Trials for the Treatment of Oral Lichen Planus: A Methodological Study

Laser spectroscopy of indium Rydberg atom bunches by electric field ionization

A direct diode pumped Ti:sapphire laser with single-frequency operation for high resolution spectroscopy

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