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1.
Target-ion source unit ionization efficiency measurement by a method of stable ion beam implantation
V. N. Panteleev A. E. Barzakh D. V. Fedorov P. L. Molkanov F. V. Moroz S. Yu. Orlov Yu. M. Volkov 《The European physical journal. Special topics》2007,150(1):301-302
At the IRIS facility a rather precise method of the
target-ion source unit ionization efficiency measurement has been
developed. The method exploits an off-line
mass-separator for the implantation of the ion beams of selected stable isotopes into a tantalum foil placed inside a Faraday
cup
in the focal plane of the mass-separator. After the
implantation of the required amount of the investigated species, tantalum foil has been inserted into
the volume of the target-ion source unit prepared for the on-line utilization at the IRIS
on-line separator. The first tests have ensured the ionization efficiency values
(90±10)% for Rb and (85±10)% for Cs in the empty combined
target-ion source unit, which was
used as a reference one. For the target-ion source unit with UC target material inside the measured value of the ionization
efficiency of Rb was (52±20)%. 相似文献
2.
M.D. Seliverstov A.E. Barzakh I.Ya. Chubukov D.V. Fedorov V.N. Panteleev Yu.M. Volkov 《Hyperfine Interactions》2000,127(1-4):425-430
The study of nuclei far from stability requires high sensitivity of the experimental technique. The method of Resonance Ionization
Spectroscopy in a Laser Ion Source (RIS/LIS) allows one to carry out measurements of the isotope shifts and hyperfine splittings
for isotopes at the production rate about 102 atoms per second. The sensitivity of this method is determined by the high efficiency of the laser ion source and the low
background of the detection system afforded by characteristic α particle registration. The isotope shifts and hyperfine structures
of 155Yb, 154Tm (I=9 and I=2) and 153Tm (I=11/2) have been measured and the isotopic changes in mean square charge radii and nuclear electromagnetic moments have
been determined.
The further development of this experimental method – enhanced Target Ion Source system aimed to suppress thermionic background
– enables direct detection of the photoions and widens the range of the applicability of the RIS/LIS method.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
M. Oba K. Akaoka M. Miyabe I. Wakaida 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(3):255-260
The laser induced fluorescence method using atomic beam combined with Doppler-free two-photon absorption technique was applied
for the measurement of isotope shifts and hyperfine structures of atomic uranium including 234U, 235U, 236U and 238U isotopes. The isotope shifts between 238U-234U, 238U-235U, 238U-236U, and the hyperfine structure of 235U were obtained in the high lying odd levels around 4 eV.
Received 3 December 2001 / Received in final form 4 July 2002 Published online 29 October 2002
RID="a"
ID="a"e-mail: oba@analchem.tokai.jaeri.go.jp 相似文献
4.
U. Klingbeil J. Kowalski F. Träger H. -B. Wiegemann G. zu Putlitz 《Zeitschrift für Physik A Hadrons and Nuclei》1979,290(2):143-148
The isotope shift40Ca-43Ca in the 4s 2 1 S 0-4s4p 3 P 1 intercombination line as well as the hyperfine structure splitting of the 4s4p 3 P 1 state of43Ca have been remeasured by saturation spectroscopy with a tunable stabilizedcw dye laser and an atomic beam of natural Ca as absorber. The nuclear charge radius of43Ca obtained here reconciles our result with the radius obtained from measurements in muonic Ca-atoms and in the Ca resonance line. It reconfirms the fact that the charge radius of43Ca is considerably smaller than the ones of both neighbouring even isotopes. The discrepancy of our previous measurement for this charge radius was due to a wrong assignment of so far unobserved absorption lines of probably molecular origin occuring in the neighbourhood of the atomic resonances under study. 相似文献
5.
K. Blaum B.A. Bushaw S. Diel Ch. Geppert A. Kuschnick P. Müller W. Nörtershäuser A. Schmitt K. Wendt 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(1):37-44
High-resolution resonance ionization mass spectrometry has been used to measure isotope shifts and hyperfine structure in
all (J
= 2-6) and the transitions of gadolinium (Gd I). Gadolinium atoms in an atomic beam were excited with a tunable single-frequency laser in
the wavelength range of 422-429 nm. Resonant excitation was followed by photoionization with the 363.8 nm line of an argon
ion laser and resulting ions were mass separated and detected with a quadrupole mass spectrometer. Isotope shifts for all
stable gadolinium isotopes in these transitions have been measured for the first time. Additionally, the hyperfine structure
constants of the upper states have been derived for the isotopes
155, 157
Gd and are compared with previous work. Using prior experimental values for the mean nuclear charge radii, derived from the
combination of muonic atoms and electron scattering data, field shift and specific mass shift coefficients for the investigated
transitions have been determined and nuclear charge parameters for the minor isotopes
152, 154
Gd have been calculated.
Received 18 November 1999 相似文献
6.
W. Nörtershäuser K. Blaum K. Icker P. Müller A. Schmitt K. Wendt B. Wiche 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,2(1):33-39
The isotope shift and hyperfine structure in the three - transitions in Ca II have been studied by fast ion beam collinear laser spectroscopy for all stable Ca isotopes. The metastable
3d states were populated within the surface ionization source of a mass separator with a probability of about 0.1%. After
resonant excitation to the 4p levels with diode laser light around 850 nm the uv photons from the transitions to the ground state were used for detection. Hyperfine structure parameters A and B for the odd isotope 43Ca, as evaluated from the splittings observed, agree well with theoretical predictions from relativistic many-body perturbation
theory. Field shift constants and specific mass shift constants were extracted from the measured isotope shifts and are discussed in comparison with expectation values from theory.
Received: 19 September 1997 / Revised: 5 December 1997 / Accepted: 27 January 1998 相似文献
7.
Backe H. Baum R. -R. Fricke B. Habs D. Hellmann K. Hies M. Illgner Ch. Krameyer Ch. Kunz H. Lauth W. Martin R. Schwamb P. Theobald W. Thörle P. Trautmann N. 《Hyperfine Interactions》1996,97(1):535-541
Istope shift and hyperfine structure measurements have been performed for the242fAm fission isomer with target production rates of only a few per second. The method is based on resonance ionization spectroscopy (RIS) in a buffer gas cell with radioactive decay detection of the ionization process (RADRIS). A relative isotope shift ratioX
exp=IS242f,241/ IS243,241=41.7±0.9 has been measured for the 500.02 nm transition corresponding to a nuclear parameter 242f,241=5.4±0.3 fm2. The analysis of the quadrupole moment based on the deformed Fermi-model of the nuclear charge distribution including second order corrections results inQ
20=38.2 ±1.4(
–0.8
+0.4
)model eb. The measurement of the hyperfine structure splitting of the transition at 466.28 nm yields a negativeg-factor and a nuclear spin ofI=2 orI=3.Work supported by the Bundesministerium für Bildung und Forschung under contract 06 MZ 5661. 相似文献
8.
A new version of integrated target-ion source unit (ionising target) has been developed for the on-line production of radioactive
single-charged ions. The target is able to withstand temperatures up to 2500 °C and acts also as an ion source of the surface and laser ionisation. Off-line and on-line experiments with the ionising target,
housing tantalum foils as a target material, have been carried out at the IRIS (Investigation of Radioactive Isotopes on Synchrocyclotron)
facility. The off-line surface ionisation efficiency measured for stable atoms of Li, Rb and Cs was correspondingly 6% , 40%
and 55% at the target temperature of 2000 °C and 3-10% for atoms of rare-earth elements Sm, Eu, Tm and Yb at a temperature of 2200 °C. The off-line measured values of the ionisation efficiency for stable Gd and Eu atoms by the laser beam ionisation inside
the target were 1% and 7%, respectively. The radioactive beam intensities of neutron-deficient rare-earth nuclides from Eu
to Lu produced by the integrated target-ion source unit have been measured at a temperature of 2500 °C. The results of the integrated target-ion source unit use for on-line laser resonance ionisation spectroscopy study of neutron-deficient
Gd isotopes have been also presented. 相似文献
9.
M. Wieland T. Wilhein M. Faubel Ch. Ellert M. Schmidt O. Sublemontier 《Applied physics. B, Lasers and optics》2001,72(5):591-597
A liquid jet of either nitrogen or argon of 20 μm diameter was exposed to intense laser fields with pulse durations between
70 fs and 250 ps, leading to intensities of 1016 W cm-2 and 1013 W cm-2, respectively. The emission of extreme UV light and soft X-rays shows the characteristic lines of hydrogen-like nitrogen
and carbon-like argon. For nitrogen the emitted photon flux at 250 ps was about two orders of magnitude higher than for 70 fs
pulses. A weak dependence on the laser polarization with respect to the liquid jet axis was found. The kinetic energy of the
emitted ions easily exceeded 100 keV for nitrogen and 200 keV for argon for a pulse duration close to 2 ps.
Received: 21 August 2000 / Revised version: 20 December 2000 / Published online: 22 March 2001 相似文献
10.
E. Nir Ch. Plützer K. Kleinermanns M. de Vries 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,20(3):317-329
The vibronic spectra of laser desorbed and jet cooled guanine (G) adenine (A), and cytosine (C) consist of bands from four,
two and two major tautomers respectively, as revealed by UV-UV and IR-UV double resonance spectroscopy. The vibronic spectrum
of adenine around 277 nm consists of weak nπ* and strong ππ* transitions, based on IR-UV and deuteration experiments. Precise ionization potentials of G and A were determined with 2-color,
2-photon ionization. We also measured vibronic and IR spectra of several base pairs. GC exhibits a HNH ... OH/NH ... N/C=O ... HNH bonding similar to the Watson-Crick GC base pair but with C as enol tautomer. One GG isomer exhibits non-symmetric hydrogen
bonding with HNH ... N/NH ... N/C=O ... HNH interactions. A second observed GG isomer has a symmetrical hydrogen bond arrangement with C=O ... NH/NH ... O=C bonding. Two CC isomers were observed with symmetrical C=O ... NH/NH ... O=C bonding and nonsymmetrical C=O ... HNH/NH ... N interaction, respectively. Guanosine (Gs), 2-DeoxyGs und 3-DeoxyGs each exhibit only one isomer in the investigated wavelength
range around 290 nm with a strong intramolecular sugar(5-OH) ... enolguanine(3-N) hydrogen bond.
Received 16 June 2002 / Received in final form 15 July 2002 Published online 13 September 2002 相似文献
11.
J.L. Blows P. Dekker P. Wang J.M. Dawes T. Omatsu 《Applied physics. B, Lasers and optics》2003,76(3):289-292
By using holographic shear interferometry, we have measured the thermal lens in a diode-pumped Yb:YAB crystal, under lasing
and non-lasing conditions, as a function of absorbed power. From these purely optical measurements we estimate the fractional
thermal loading and the thermal conductivity of Yb:YAB. Knowledge of these thermal parameters is essential for the optimisation
of Yb:YAB laser cavity designs.
Received: 5 February 2002 / Final version: 22 November 2002 / Published online: 26 February 2003
RID="*"
ID="*"Corresponding author. Fax +61-2/9850-8915, E-mail: Judith@ics.mq.edu.au 相似文献
12.
H. Zhang X. Meng P. Wang L. Zhu X. Liu R. Cheng J. Dawes P. Dekker S. Zhang L. Sun 《Applied physics. B, Lasers and optics》1999,68(6):1147-1149
Yb:Ca4YO(BO3)3 (Yb:YCOB) crystal with good quality and large size has been grown by the Czochralski method. The polarization absorption
and fluorescence spectra have been measured. The laser action of the Yb:YCOB crystal has been demonstrated when it is pumped
by a fiber-coupled laser diode (LD) at the wavelength of 976.4 nm. The pumping threshold is 55 mW, the light-light conversion
efficiency is 58.7%, and a slope efficiency of up to 73% is thus calculated.
Received: 16 December 1998 / Revised version: 4 February 1999 / Published online: 7 April 1999 相似文献
13.
A.S. Grabtchikov A.N. Kuzmin V.A. Lisinetskii V.A. Orlovich A.A. Demidovich M.B. Danailov H.J. Eichler A. Bednarkiewicz W. Strek A.N. Titov 《Applied physics. B, Lasers and optics》2002,75(6-7):795-797
We present a diode-pumped Yb:KYW microchip laser. The passive Q-switchedand CW regimes of operation for the Yb:KYW microchip
laser have been investigated. An efficiency for CW operation of up to 10% with regard to incident pump has been obtained.
Raman self-frequency conversion in the Q-switched regime has been observed.
Received: 27 May 2002 / Revised version: 4 July 2002 / Published online: 15 November 2002
RID="*"
ID="*"Corresponding author. Fax: +375-17/2840-879, E-mail: asg@dragon.bas-net.by 相似文献
14.
The temperature and excitation wavelength dependencies of 3-pentanone absorption and fluorescence were studied in support
of planar laser-induced fluorescence (PLIF) imaging of temperature and mixture fraction in flows of practical interest. The
temperature dependencies (300–875 K) of absorption and fluorescence were measured for gaseous 3-pentanoneat atmospheric pressure
in a nitrogen bath gas using 248, 266, and 308 nm excitation. The results indicate that the fluorescence signal per unit mole
fraction using 248 nm excitation is highly temperature-sensitive below 600 K, while the signal from 308 nm excitation is not
temperature sensitive below 500 K. For quantitative measurements over a broad range of temperatures, one must choose excitation
schemes carefully to balance the trade-off between measurement sensitivity and the amount of signal at the expected conditions.
As an example of such a choice and to show the capabilities of ketone PLIF techniques, we include temperature and mixture
fraction images of a 300–650 K heated air jet using near-simultaneous 308 and 266 nm excitation.
Received: 29 May 2002 / Revised version: 5 November 2002 / Published online: 26 February 2003
RID="*"
ID="*"Corresponding author. Fax: +1-650/723-1748, E-mail: jkoch@stanford.edu
RID="**"
ID="**"E-mail: hanson@me.stanford.edu 相似文献
15.
S. Guérandel T. Badr M.D. Plimmer P. Juncar M.E. Himbert 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,10(1):33-38
The frequency of the centroid of the transition in Ag I has been determined by laser spectroscopy of a collimated metastable thermal atomic beam. We find MHz. The isotope shift MHz. For the magnetic hyperfine structure constant of the state, assuming IJ coupling, we find, MHz and MHz.
Received 16 July 1999 and Received in final form 7 October 1999 相似文献
16.
A high-sensitivity in situ optical diagnostic technique for laser cleaning of transparent substrates
N. Chaoui J. Solis C.N. Afonso T. Fourrier T. Muehlberger G. Schrems M. Mosbacher D. Bäuerle M. Bertsch P. Leiderer 《Applied Physics A: Materials Science & Processing》2003,76(5):767-771
A differential optical transmission technique has been used to monitor in situ the efficiency of laser cleaning for the removal
of sub-micrometer-sized particles on substrates transparent at the monitoring wavelength. This technique has been applied
to the removal of sub-micrometer polystyrene particles on polyimide substrates using laser pulses of 30 ps duration at 292 nm
while probing the material transmission at 633 nm. The sensitivity achieved -1/104 for the transmission changes induced upon single-pulse laser exposure – allows us to monitor the removal of just a few sub-micron-sized
particles from the probed region inside the irradiated area.
Received: 2 October 2002 / Accepted: 7 October 2002 / Published online: 29 January 2003
RID="*"
ID="*"Corresponding author. Fax: +33-3/87844082, E-mail: nchaoui@iut.univ-metz.fr
RID="**"
ID="**"Present address: Laboratoire de Chimie et Applications, Institut Universitaire de Technologie de Metz, Département
Chimie, Rue Victor Demange, 57500 Saint-Avold, France 相似文献
17.
The feasibility of liquid-phase velocity measurements in dense sprays by 2D laser-based flow tagging is demonstrated. Velocity
measurements in dense sprays are difficult with conventional techniques because of the high number densities of droplets,
the optical thickness of the medium, and multiple light-scattering effects. The present flow-tagging technique is based on
phosphorescent tracer molecules, which are excited by a grid of pulsed ‘write’ laser beams. The motion of the tagged droplet
groups can be observed by a CCD camera in this way. In addition, multiple consecutive velocity measurements are performed
by ‘droplet-group tracking’. This yields the acceleration along the trajectory of individual groups of droplets in unsteady
sprays.
Received: 5 June 2000 / Revised version: 28 July 2000 / Published online: 6 September 2000 相似文献
18.
S. Urabe M. Watanabe H. Imajo K. Hayasaka U. Tanaka R. Ohmukai 《Applied physics. B, Lasers and optics》1998,67(2):223-227
1/2 -D5/2 electric-quadrupole-allowed transitions of a laser-cooled Ca+ ion in a small rf trap. The electron shelving method was used to measure the absorption spectrum of the electric-quadrupole-allowed
transitions, and the motional sidebands due to the secular motion of the ion in the harmonic potential well of the rf trap
were completely resolved. The effective temperature of the ion, estimated by comparing the observed sideband intensities with
the theoretical ones, was less than 4.4 mK. This result is in good agreement with that obtained from the analysis of the linewidth
measurement.
Received: 18 March 1998 相似文献
19.
Hopp B. Smausz T. Kresz N. Nagy P.M. Juhász A. Ignácz F. Márton Z. 《Applied Physics A: Materials Science & Processing》2003,76(5):731-735
Allergic-type diseases are current nowadays, and they are frequently caused by certain metals. We demonstrated that the metal
objects can be covered by Teflon protective thin layers using a pulsed laser deposition procedure. An ArF excimer laser beam
was focused onto the surface of pressed PTFE powder pellets; the applied fluences were 7.5–7.7 J/cm2. Teflon films were deposited on fourteen-carat gold, silver and titanium plates. The number of ablating pulses was 10000.
Post-annealing of the films was carried out in atmospheric air at oven temperatures between 320 and 500 °C. The thickness
of the thin layers was around 5 μm. The prepared films were granular without heat treatment or after annealing at a temperature
below 340 °C. At 360 °C a crystalline, contiguous, smooth, very compact and pinhole-free thin layer was produced; a melted
and re-solidified morphology was observed above 420 °C. The adhesion strength between the Teflon films and the metal substrates
was determined. This could exceed 1–4 MPa depending on the treatment temperature. It was proved that the prepared Teflon layers
can be suitable for prevention of contact between the human body and allergen metals and so for avoidance of metal allergy.
Received: 12 June 2002 / Accepted: 13 June 2002 / Published online: 4 November 2002
RID="*"
ID="*"Corresponding author. E-mail: bhopp@physx.u-szeged.hu 相似文献