Related papers: A New Method of Measuring 81Kr and 85Kr Abundances…
We report a methodology for measuring 85Kr/Kr isotopic abundances using Atom Trap Trace Analysis (ATTA) that increases sample measurement throughput by over an order of magnitude to 6 samples per 24 hours. The noble gas isotope 85Kr…
We place a 2.5% limit on the anthropogenic contribution to the modern abundance of 81Kr/Kr in the atmosphere at the 90% confidence level. Due to its simple production and transport in the terrestrial environment, 81Kr (halflife = 230,000…
The noble gas radionuclides, including 81Kr (half-life = 229,000 yr), 85Kr (11 yr), and 39Ar (269 yr), possess nearly ideal chemical and physical properties for studies of earth and environmental processes. Recent advances in Atom Trap…
Trace analysis of radionuclides is an essential and versatile tool in modern science and technology. Due to their ideal geophysical and geochemical properties, long-lived noble gas radionuclides, in particular, 39Ar (t1/2 = 269 yr), 81Kr…
Atom Trap Trace Analysis (ATTA), a novel method based upon laser trapping and cooling, is used to count individual atoms of 41Ca present in biomedical samples with isotopic abundance levels between 10^-8 and 10^-10. ATTA is calibrated…
Measurements of 81Kr/Kr in deep groundwater from the Nubian Aquifer (Egypt) were performed by a new laser-based atom-counting method. 81Kr ages range from \~2x10^5 to ~1x10^6 yr, correlate with 36Cl/Cl ratios, and are consistent with…
We have developed an atom trap trace analysis (ATTA) system to measure Kr in Xe at the part per trillion (ppt) level, a prerequisite for the sensitivity achievable with liquid xenon dark matter detectors beyond the current generation. Since…
We report an increase of up to 60% on the count rates of the rare $^{81}\mathrm{Kr}$ and $^{85}\mathrm{Kr}$ isotopes in the Atom Trap Trace Analysis method by enhancing the production of metastable atoms in the discharge source. Additional…
Atom Trap Trace Analysis (ATTA), a laser-based atom counting method, has been applied to analyze atmospheric Ar-39 (half-life = 269 yr), a cosmogenic isotope with an isotopic abundance of 8x10^-16. In addition to the superior selectivity…
The beta-decay of $\rm^{85}Kr$ is a significant radioactive background for experiments that use liquified noble gases to search for dark matter and measure the low-energy solar neutrino flux. While there are several proposed methods for…
We present the first successful 81Kr-Kr radiometric dating of ancient polar ice. Krypton was extracted from the air bubbles in four ~350 kg polar ice samples from Taylor Glacier in the McMurdo Dry Valleys, Antarctica, and dated using Atom…
Krypton-85 is an anthropogenic beta-decaying isotope which produces low energy backgrounds in dark matter and neutrino experiments, especially those based upon liquid xenon. Several technologies have been developed to reduce the Kr…
The results of the experiment searching for 2K-capture with large low-background proportional counter are presented. The comparison of spectra of the background of the proportional counter filled with Kr enriched in $^{78}$Kr (8400 hr) and…
The determination of isotope ratios of noble gas atoms has many applications e.g. in physics, nuclear arms control, and earth sciences. For several applications, the concentration of specific noble gas isotopes (e.g. Kr and Ar) is so low…
We have demonstrated that the ion current resulting from collisions between metastable krypton atoms in a magneto-optical trap can be used to precisely measure the trap loading rate. We measured both the ion current of the abundant isotope…
The neutrino mass experiment KATRIN uses conversion electrons from the 32.2 keV transition of the nuclear isomer $^{\mathrm{83m}}$Kr for calibration. Comparing the measured energies to the appropriate literature values allows for an…
In-plane thermal conductivities of small-scale samples are hard to measure, especially for the lowly conductive ones and those lacking in-plane symmetry (i.e., transversely anisotropic materials). State-of-the-art pump-probe techniques…
For expressive music, the tempo may change over time, posing challenges to tracking the beats by an automatic model. The model may first tap to the correct tempo, but then may fail to adapt to a tempo change, or switch between several…
A new detection system KRATTA, Krak\'ow Triple Telescope Array, is presented. This versatile, low threshold, broad energy range system has been built to measure the energy, emission angle, and isotopic composition of light charged reaction…
The cosmic-ray ionization rate (CRIR, $\zeta_2$) is one of the key parameters controlling the formation and destruction of various molecules in molecular clouds. However, the current most commonly used CRIR tracers, such as H$_3^+$, OH$^+$,…