Search results for " atom"
showing 10 items of 1526 documents
Residual Phase Noise Measurement of Optical Second Harmonic Generation in PPLN Waveguides
2017
We report on the characterization, including residual phase noise and fractional frequency instability, of fiber-coupled PPLN non-linear crystals. These components are devoted to frequency doubling 871 nm light from an extended-cavity diode laser to produce a 435.5 nm beam, corresponding to the ytterbium ion electric quadrupole clock transition. We measure doubling efficiencies of up to 117.5 %/W. Using a Mach-Zehnder interferometer and an original noise rejection technique, the residual phase noise of the doublers is estimated to be lower than ${\rm -35\, dBrad^2/Hz}$ at 1 Hz, making these modules compatible with up-to-date optical clocks and ultra-stable cavities. The influence of externa…
Phase-Noise and Amplitude-Noise Measurement of DACs and DDSs
2019
This article proposes a method for the measurement of Phase Noise (PN, or PM noise) and Amplitude Noise (AN, or AM noise) of Digital-to-Analog Converters (DAC) and Direct Digital Synthesizers (DDS) based on modulation-index amplification. The carrier is first reduced by a controlled amount (30-40 dB) by adding a reference signal of nearly equal amplitude and opposite in phase. Then, residual carrier and noise sidebands are amplified and sent to a conventional PN analyzer. The main virtues of our method are: (i) the noise specs of the PN analyzer are relaxed by a factor equal to the carrier suppression ratio; and, (ii) the capability to measure the AN using a PN analyzer, with no need for th…
Targeting G-quadruplexes with Organic Dyes: Chelerythrine–DNA Binding Elucidated by Combining Molecular Modeling and Optical Spectroscopy
2019
The DNA-binding of the natural benzophenanthridine alkaloid chelerythrine (CHE) has been assessed by combining molecular modeling and optical absorption spectroscopy. Specifically, both double-helical (B-DNA) and G-quadruplex sequences&mdash
Kaon-proton strong interaction at low relative momentum via femtoscopy in Pb-Pb collisions at the LHC
2021
Physics letters / B 822, 136708 (2021). doi:10.1016/j.physletb.2021.136708
Towards high-accuracy mass spectrometry of highly charged short-lived ions at ISOLTRAP
2006
Dedicated to H.-J. Kluge on the occasion of his 65th birthday anniversary - Jürgen Kluge Special Issue; Multiply charged ions of stable xenon isotopes from a plasma ion source have been mass-selected by the on-line mass separator ISOLDE/CERN and delivered to the triple-trap mass spectrometer ISOLTRAP. The doubly charged ions that survived the charge-exchange processes during bunching and ion preparation were transferred to a precision Penning trap for mass determination. Mass values were obtained for the isotopes with mass numbers A=126,129,130,136. They are consistent with previous results except for the case of $^{126}Xe$ where a significant deviation from the literature value was found. …
Modelling the effect of nuclear motion on the attosecond time-resolved photoelectron spectra of ethylene
2014
arXiv:1403.5408
Measurement of light-by-light scattering and search for axion-like particles with 2.2 nb−1 of Pb+Pb data with the ATLAS detector
2021
We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; ANID, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF and DNSRC, Denmark; IN2P3-CNRS and CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, HGF and MPG, Germany; GSRT, Greece; RGC and Hong Kong SAR, China; ISF and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Mor…
Search for Axionlike Dark Matter through Nuclear Spin Precession in Electric and Magnetic Fields
2017
We report on a search for ultralow-mass axionlike dark matter by analyzing the ratio of the spinprecession frequencies of stored ultracold neutrons and 199Hg atoms for an axion-induced oscillating electric dipole moment of the neutron and an axion-wind spin-precession effect. No signal consistent with dark matter is observed for the axion mass range 10−24 ≤ ma ≤ 10−17 eV. Our null result sets the first laboratory constraints on the coupling of axion dark matter to gluons, which improve on astrophysical limits by up to 3 orders of magnitude, and also improves on previous laboratory constraints on the axion coupling to nucleons by up to a factor of 40. ispartof: Physical Review X vol:7 issue:…
Ocena jednorodności zanieczyszczenia kory drzew liściastych metalami ciężkimi
2018
Celem badań była ocena jednorodności zanieczyszczenia metalami ciężkimi (Ni, Cu, Zn, Cd i Pb) kory drzew liściastych pobranej z lasu mieszanego na terenie gminy Ozimek (województwo opolskie). W ramach biomonitoringu pasywnego pobrano próbki kory z trzech gatunków drzew liściastych: z brzozy brodawkowatej (Betula pendula Roth.), buka zwyczajnego (Fagus sylvatica L.) oraz z dębu szypułkowego (Quercus robur L.). Metale ciężkie oznaczono za pomocą absorpcyjnej spektrometrii atomowej (AAS). Na podstawie przeprowadzonych badań można jednoznacznie stwierdzić, że kora drzew wykorzystanych do badań różni się pod względem stężeń metali ciężkich. Największe średnie zawartości Cu, Zn, Cd i Pb występują…
Kora brzozy brodawkowatej jako biomonitor zanieczyszczenia powietrza metalami ciężkimi
2018
Celem przeprowadzonych badań była ocena możliwości wykorzystania kory brzozy brodawkowatej (Betula pendula Roth) w biomonitoringu terenów leśnych. Do badań wykorzystano korę drzew rosnących na obszarze Beskidów i Puszczy Boreckiej. W korze, metodą absorpcyjnej spektrometrii atomowej ze wzbudzeniem w płomieniu (F-AAS), oznaczono stężenia metali ciężkich: Mn, Fe, Ni, Cu, Zn, Cd oraz Pb. Na podstawie przeprowadzonych badań stwierdzono sezonowe zmiany stężenia analitów. Wykazano również, że kora brzozy brodawkowatej może być wykorzystywana jako bioindykator do oceny zanieczyszczenia aerozolu atmosferycznego na tych obszarach np. metalami ciężkimi. Ważne jest jednak, aby dokonać walidacji poszcz…