共查询到20条相似文献,搜索用时 31 毫秒
1.
V. N. Fedosseev B. A. Marsh D. V. Fedorov U. Köster E. Tengborn 《Hyperfine Interactions》2005,162(1-4):15-27
The resonance ionization laser ion source (RILIS) of the ISOLDE on-line isotope separation facility is based on the method
of laser step-wise resonance ionization of atoms in a hot metal cavity. The atomic selectivity of the RILIS complements the
mass selection process of the ISOLDE separator magnets to provide beams of a chosen isotope with greatly reduced isobaric
contamination. Using a system of dye lasers pumped by copper vapour lasers, ion beams of 24 elements have been generated at
ISOLDE with ionization efficiencies in the range of 0.5–15%. As part of the ongoing RILIS development off-line resonance ionization
spectroscopy studies carried out in 2003 and 2004 have determined the optimal three-step ionization schemes for scandium,
antimony, dysprosium and yttrium. 相似文献
2.
M. Oinonen Y. Jading U. Köster J. Lettry H. Ravn J. Äystö P. Dendooven J. Huikari A. Jokinen P.O. Lipas A. Nieminen K. Peräjärvi T. Siiskonen P. Baumann A. Huck A. Knipper M. Ramdhane G. Walter F. Didierjean V.N. Fedoseyev V.I. Mishin M. Koizumi W. Liu E. Roeckl V. Sebastian 《Hyperfine Interactions》2000,127(1-4):431-436
Resonance ionization laser ion source (RILIS) technique has been used in the β-decay studies of 59Mn and 58Zn. The importance of the RILIS for production of these elements is discussed. The properties of the low-lying levels of the
studied nuclei are discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
M. Seliverstov A. Andreyev N. Barré H. De Witte D. Fedorov V. Fedoseyev S. Franchoo J. Genevey G. Huber M. Huyse U. Köster P. Kunz S. Lesher B. Marsh B. Roussière J. Sauvage P. Van Duppen Yu. Volkov 《Hyperfine Interactions》2006,171(1-3):225-231
Mean-square charge radii and magnetic moments have been measured for the neutron deficient lead isotopes, 182–190Pb. The measurement was performed at the ISOLDE online mass separator, using the in-source resonance ionization spectroscopy
technique. The wavelength of the first excitation step for the resonance ionization laser ion source (RILIS) was scanned over
the resonance(s) whilst the α- and γ-ray spectra from the decay of the Pb isotopes were recorded as a function of the wavelength. The isotope shift and, in the
case of odd-A isotopes, the hyperfine splitting were deduced. The rms-charge radii of the very neutron deficient Pb isotopes follow the
smooth trend of the heavier isotopes. This finding indicates a spherical shape for the lead ground states at the neutron mid-shell
(N = 104), where the excitation energy of the oblate 0+ state in the even isotopes reaches its minimum. 相似文献
4.
J. Lassen P. Bricault M. Dombsky J. P. Lavoie Ch. Geppert K. Wendt 《Hyperfine Interactions》2005,162(1-4):69-75
Resonant laser excitation and ionisation is one of the most successful tools for the selective production of radioactive ion beams (RIB) at on-line mass separator facilities. TRIUMF plans to augment the current ion sources with a resonant ionisation laser ion source (RILIS), to use the high production yields from the target, as shown by the delivery of 3*104/s 11Li ions from a standard target ion source with surface ionisation. The development and installation of TRIUMF's RILIS (TRILIS)
is necessary to provide beams of short lived isotopes that conventional ion sources could not produce in sufficient intensity
and purity for nuclear-, and nuclear astrophysics- experiments. A laser system consisting of three tunable titanium–sapphire (TiSa) lasers with frequency doubling and tripling was employed to demonstrate first off-line resonance ionisation
of Ga, and is being installed for first on-line test and a run on 62Ga in December 2004. 相似文献
5.
E. J. Prime J. Lassen T. Achtzehn D. Albers P. Bricault T. Cocolios M. Dombsky F. Labrecque J. P. Lavoie M. R. Pearson T. Stubbe N. Lecesne Ch. Geppert K. D. A. Wendt 《Hyperfine Interactions》2006,171(1-3):127-134
The range of isotopes available at the TRIUMF Isotope Separator Accelerator (ISAC) facility has been greatly enhanced by adding
a Resonance Ionization Laser Ion Source (RILIS). A large wavelength range is accessible with the fundamental, second and third
harmonic generation of titanium-sapphire laser light. In addition a dedicated laser is available for non-resonant laser ionization.
The first on-line beam 62Ga was delivered in Dec. 2004. In general RILIS improves the intensity, purity and emittance of ion beams. 62Ga and 26Al and Be beams have been delivered so far on-line.
This work was financed by TRIUMF which is federally funded via a contribution agreement through the National Research Council
of Canada. 相似文献
6.
Yuan Liu 《Hyperfine Interactions》2014,227(1-3):85-99
The development of a resonant ionization laser ion source (RILIS) for the production of isotopically pure radioactive ion beams is reported. The application of the laser ion source calls for high elemental selectivity, high efficiency, and fast release of short-lived isotopes. A hot-cavity ion source and three Ti:sapphire lasers pulsed at a 10 kHz rate are employed for the RILIS. The Ti:sapphire lasers have been upgraded with individual pump lasers to eliminate intracavity Pockels cells and output losses due to synchronization delays. The development of ionization schemes for a wide range of elements is important to the success of Ti:sapphire-laser-based RILIS. In off-line studies with stable isotopes, resonant ionization of 14 elements has been studied, leading to new ionization schemes for ten elements. The absolute ionization efficiency of the hot-cavity RILIS has been measured to range from 0.9 % to 40 % for different elements. The mechanisms for ion transportation and confinement in the hot-cavity ion source have been studied using the temporal profiles of the laser-ionized ions. The hot-cavity RILIS has provided beams of neutron-rich $^{83,85,86}$ Ga isotopes for beta decay studies and enabled the first measurement of the beta decay of the exotic $^{86}$ Ga. 相似文献
7.
At the ISOLDE on-line isotope separation facility, the resonance ionisation laser ion source (RILIS) can be used to ionise
reaction products as they effuse from the target. The RILIS process of laser step-wise resonance ionisation of atoms in a
hot metal cavity provides a highly element selective stage in the preparation of the radioactive ion beam. As a result, the
ISOLDE mass separators can provide beams of a chosen isotope with greatly reduced isobaric contamination. With the addition
of a new three-step ionisation scheme for gold, the RILIS is now capable of ionising 26 of the elements. The optimal scheme
was determined during an extensive study of the atomic energy levels and auto-ionising states of gold, carried out by means
of in-source resonance ionisation spectroscopy. Details of the ionisation scheme and a summary of the spectroscopy study are
presented. 相似文献
8.
A. Teigelhöfer J. Lassen Z. Abboud P. Bricault H. Heggen P. Kunz R. Li T. Quenzel S. Raeder 《Hyperfine Interactions》2013,216(1-3):65-70
Resonant ionization laser ion sources (RILIS) are popular ion sources if intense, radioactive ion beams (RIBs) with minimal isobaric contamination are required. The intensity of the ion beam depends strongly on the applied resonant laser ionization scheme. Based on the all solid state laser system TRIUMF’s RILIS (TRILIS) is using, the off-line development towards an efficient ionization scheme for yttrium is presented. Several continuous wavelength scans have been performed to compare different nonresonant ionization schemes and to identify suitable Rydberg or autoionizing states for resonant ionization schemes. 相似文献
9.
U. Köster R. Catherall V.N. Fedoseyev S. Franchoo U. Georg M. Huyse K. Kruglov J. Lettry V.I. Mishin M. Oinonen H. Ravn M.D. Seliverstov H. Simon P. Van Duppen J. Van Roosbroeck L. Weissman 《Hyperfine Interactions》2000,127(1-4):417-420
Short-lived radioisotopes are element selectively ionized by the resonance ionization laser ion source (RILIS) of the on-line
isotope separator ISOLDE (CERN). The relative production of low and high spin isomers can be significantly changed when a
narrow-bandwidth laser is used to scan through the atomic hyperfine structure. This allows the assignment of gamma ray transitions
to the decay of the individual isomers. Moreover, the measurement of the hyperfine splitting provides a very sensitive method
for the determination of magnetic moments of exotic isotopes. The technical developments are discussed for the example of
copper.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
10.
V.N. Fedoseyev G. Huber U. Köster J. Lettry V.I. Mishin H. Ravn V. Sebastian 《Hyperfine Interactions》2000,127(1-4):409-416
At the ISOLDE on line mass separator a system of copper vapor lasers and dye lasers serves for resonant ionization of atoms
inside a hot cavity attached to the target. Radioactive ion beams of Yb, Ag, Mn, Ni, Zn, Be, Cu, Cd and Sn were produced with
the Resonance Ionization Laser Ion Source (RILIS). Two and three step excitation schemes are used, providing an ionization
efficiency of about 10%. Thanks to the use of the RILIS it became possible to ionize beryllium efficiently at ISOLDE, and
all particle stable Be isotopes could be separated for the first time. Separation of Ag and Cu nuclear isomers was achieved
in the ion source by appropriate tuning of the laser wavelength. New isotopes of Ag, Mn, Zn, Cd and Sn were found, including
the r process “waiting point” nucleus 129Ag.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
11.
B. A. Marsh L.-E. Berg D. V. Fedorov V. N. Fedosseev O. J. Launila M. Lindroos R. Losito F. K. ?sterdahl T. Pauchard I. T. Pohjalainen U. Sassenberg M. D. Seliverstov A. M. Sj?din G. Transtr?mer 《Hyperfine Interactions》2010,196(1-3):129-141
On account of its high efficiency, speed and unmatched selectivity, the Resonance Ionization Laser Ion Source (RILIS) is the preferred method for ionizing the nuclear reaction products at the ISOLDE on-line isotope separator facility. By exploiting the unique electronic energy level ‘fingerprint’ of a chosen element, the RILIS process of laser step-wise resonance ionization enables an ion beam of high chemical purity to be sent through the mass selective separator magnet. The isobaric purity of a beam of a chosen isotope is therefore greatly increased. The RILIS, comprising of up to three frequency tunable pulsed dye lasers has been upgraded with the installation of a Nd:YAG pump laser as a replacement for the old Copper Vapor Laser (CVL) system. A summary of the current Nd:YAG pumped RILIS performance is given. To accompany the RILIS pump laser upgrade, a new ionization scheme for manganese has been developed at the newly constructed LAser Resonance Ionization Spectroscopy (LARIS) laboratory and successfully applied for on-line RILIS operation. An overview of the LARIS facility is given along with details of the ionization scheme development work for manganese. 相似文献
12.
P. Campbell 《Hyperfine Interactions》2006,171(1-3):143-148
The use of optical pumping in an RF linear Paul trap is shown to permit efficient collinear laser spectroscopy in systems
where atomic ground state resonance lines are ill-suited to the fast beam technique. The case of yttrium, where laser spectroscopy
has been used to study 86–90,92–102Y and isomeric states of 87–90,93,96,97,98Y, is highlighted. 相似文献
13.
14.
15.
G. Renault B. S. Nielsen J. Westergaard J. J. Gaardhoje 《Czechoslovak Journal of Physics》2005,55(12):1671-1674
A Large Ion Collider Experiment (ALICE) is the only experiment at the Large Hadron Collider (LHC) dedicated to the study of
heavy ion collisions. The Time Projection Chamber (TPC) is the main tracking detector covering the pseudo rapidity range |η|
< 0.9. It is designed for a maximum multiplicity dN/dy = 8000. The aim of the laser system is to simulate ionizing tracks at predifined positions throughout the drift volume in
order to monitor the TPC response to a known source. In particular, the alignment of the read-out chambers will be performed,
and variations of the drift velocity due to drift field imperfections can be measured and used as calibration data in the
physics data analysis. In this paper we present the design of the pulsed UV laser and optical system, together with the control
and monitoring systems.
for the ALICE Collaboration
Presented in the Poster Session “Future Experiments and Facilities” at the 18th International Conference “Quark Matter 2005”,
Budapest, Hungary, 4–9 August 2005. 相似文献
16.
Mohamed A. Mahmoud 《Central European Journal of Physics》2008,6(3):530-538
We have studied the formation of the molecular ion Rb2+ and the atomic ion Rb+. These are created in laser excited rubidium vapor at the first resonance, 5s–5p and 5p-nl transitions. A theoretical model
is applied to this interaction to explain the time evolution and the laser-power dependence of the population density of Rb+ and Rb2+. A set of rate equations which describe: the temporal variation of the population density of the excited states; the atomic
ion density; and the electron density, were solved numerically under the experimental conditions of Barbier and Cheret. In
their experiment the Rb concentration was 1×1013cm−3 and the laser power was taken to be 50–500 mW at vapor temperature = 450 K. The results showed that the main processes for
producing Rb2+ are associative ionization and Hornbeck-Molnar ionization. The calculations have also showed that, the atomic ions Rb+ are formed through the Penning Ionization (PI) and photoionization processes. Moreover, a reasonable agreement between the
experimental results and our calculations for the ion currents of the Rb+ and Rb2+ is obtained.
相似文献
17.
K. Blaum D. Beck G. Bollen P. Delahaye C. Guénaut F. Herfurth A. Kellerbauer H.-J. Kluge U. Köster D. Lunney S. Schwarz L. Schweikhard C. Yazidjian 《Hyperfine Interactions》2005,162(1-4):173-179
We have demonstrated for the first time that element-selective laser ionization in combination with ultra-high resolution
mass spectrometry can be used to prepare isomerically pure ion ensembles. Together with β–γ coincidence studies this method allowed a determination of the low-energy structure and the unambiguous identification of
triple β-decaying isomerism in 70Cu. By selective resonant ionization and measurement of the masses of these three states using ISOLTRAP at ISOLDE/CERN with
a relative uncertainty of δm/m ≈ 5 ⋅ 10−8 a clear state-to-mass assignment was possible which resolved the assignment puzzle in 70Cu. 相似文献
18.
A.?A.?Ionin Yu.?M.?Klimachev A.?Yu.?Kozlov A.?A.?Kotkov O.?A.?Romanovskii L.?V.?Seleznev D.?V.?Sinitsyn O.?V.?Kharchenko
In the present work it is demonstrated that a wideband CO laser operating at fundamental and overtone vibrational transitions
is a promising source of laser radiation for remote laser sensing of the atmosphere. A compact slab RF-discharge CO laser
has been designed. The optimal operating conditions are determined for this CO laser. In experiments, the maximum average
output laser power was ∼12 W for lasing efficiency of ∼14%. Under fixed experimental conditions, stable lasing (with fluctuations
of the output laser characteristics ≤5%) was observed during more than one hour, which suggests that we first excited the
sealed-off mode of cryogenic slab RF-discharge CO laser. The frequency-selective mode was first obtained for this laser. Wavelengths
for sensing of nitrous oxide, nitrogen dioxide, methane, formaldehyde, and some other gases on near-ground propagation paths
are determined. Our experiments and calculations confirm that this CO laser is promising for laser gas analysis.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 76–83, November, 2008. 相似文献
19.
Sebastian Raeder Marik Dombsky Henning Heggen Jens Lassen Thomas Quenzel Marica Sjödin Andrea Teigelhöfer Klaus Wendt 《Hyperfine Interactions》2013,216(1-3):33-39
Resonance Ionization Laser Ion Sources (RILIS) have become a versatile tool for production and study of exotic nuclides at Isotope Separator On-Line (ISOL) facilities such as ISAC at TRIUMF. The recent development and addition of a grating tuned spectroscopy laser to the TRIUMF RILIS solid state laser system allows for wide range spectral scans to investigate atomic structures on short lived isotopes, e.g., those from the element actinium, produced in uranium targets at ISAC. In addition, development of new and improved laser ionization schemes for rare isotope production at ISAC is ongoing. Here spectroscopic studies on bound states, Rydberg states and autoionizing (AI) resonances on scandium using the existing off-line capabilities are reported. These results allowed to identify a suitable ionization scheme for scandium via excitation into an autoionizing state at 58,104 cm???1 which has subsequently been used for ionization of on-line produced exotic scandium isotopes. 相似文献
20.
Reactions such as 25Al(p,γ)26Si are the key to understand the production of 26g
Al and 26m
Al in our galaxy. Experimental results could provide important constraints on nova nucleosynthesis and modelling where 26Al is believed to be produced. To achieve such measurements, high-intensity and high-purity radioactive beams are required.
However, production targets at ISOL-type facilities such as ISAC at TRIUMF produce high-intensity alkali beams by surface
ionization on hot transfer tubes hampering the measurement of isotopes of interest. To overcome this issue, an ion source
combining a segmented linear radiofrequency quadrupole (RFQ) to a laser ion source is being built. Its main function is to
suppress alkali impurities whilst allowing for fast-release of short-lived isotopes. The beam production method, the RFQ/laser
ion source and the removal of alkali contaminants are discussed in this paper. 相似文献