Zobrazeno 1 - 10
of 13
pro vyhledávání: '"James L. Hanssen"'
Publikováno v:
Metrologia. 54:247-252
The fundamental limits of atomic fountains as operational clocks are considered. Four rubidium fountains in operation at the US Naval Observatory for over 5.5 years have demonstrated unprecedented long-term stability for continuously running clocks (
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::db24df99090e8413451609aad3ae3d85
https://doi.org/10.1088/1681-7575/aa65f7
https://doi.org/10.1088/1681-7575/aa65f7
We have characterized the molecular tellurium (Te$_2$) spectrum in the vicinity of the 423nm $^1S_0-^1P_1$ and the 431nm $^3P_1-^3P_0$ transitions in neutral calcium. These transitions are relevant to optical clocks for atomic-beam characterization a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e31b097418593d9bd3d2f9766211bd88
Four rubidium fountains at the U.S. Naval Observatory (USNO) have been in operation for 4.5 years. Each fountain has demonstrated periods of stability marked by Total or Theo deviation below 10^-16. Occasional frequency changes, on order of 1.5 times
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f8204a61ad1f73f5efcb10b5f61e9d02
An ensemble of rubidium atomic fountain clocks has been put into operation at the U.S. Naval Observatory (USNO). These fountains are used as continuous clocks in the manner of commercial cesium beams and hydrogen masers for the purpose of improved ti
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8aa7f6ebd3ac48c8a994529dec5b327d
http://arxiv.org/abs/1406.1376
http://arxiv.org/abs/1406.1376
Publikováno v:
2014 IEEE International Frequency Control Symposium (FCS).
Four rubidium fountains have been in continuous operation at USNO for more than 3 years. They contribute to the local timescale and are reported to the BIPM as continuously running clocks - as opposed to secondary standards - the first and only cold-
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::4f5d91f3cb6b38d2bcaa2ca063f37e2d
https://doi.org/10.1109/fcs.2014.6859969
https://doi.org/10.1109/fcs.2014.6859969
Tests of local position invariance (LPI) made by comparing the relative redshift of atomic clocks based on different atoms have been carried out for a variety of pairs of atomic species. In most cases, several absolute frequency measurements per year
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ef0b797614721970de898f9d30c87690
http://arxiv.org/abs/1301.6145
http://arxiv.org/abs/1301.6145
Laser cooling on weak transitions is a useful technique for reaching ultracold temperatures in atoms with multiple valence electrons. However, for strongly magnetic atoms a conventional narrow-line magneto-optical trap (MOT) is destabilized by compet
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c7ea2ce7be1728fd4bfca49616712bd8
Publikováno v:
Physical Review A. 74
The evolving field of nanofabrication demands that more precise fabrication and evaluation tools be developed. We describe a method for creating a high quality focused ion beam with enhanced capabilities using an ion source based on laser-cooled neut
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c92a58daea1b7e1d645bdc7bb194506a
https://doi.org/10.1103/physreva.74.063416
https://doi.org/10.1103/physreva.74.063416
Autor:
Jabez J. McClelland, James L. Hanssen
Publikováno v:
Physical review letters. 96(14)
We report on a novel mechanism that allows for strong laser cooling of atoms that do not have a closed cycling transition. This mechanism is observed in a magneto-optical trap (MOT) for erbium, an atom with a very complex energy level structure with
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::779bd7448466eb22dd397641105d4414
https://pubmed.ncbi.nlm.nih.gov/16712071
https://pubmed.ncbi.nlm.nih.gov/16712071
Publikováno v:
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures. 24:2907
The authors describe a new method for creating a high quality focused ion beam using laser-cooled neutral atoms in a magneto-optical trap as an ion source. They show that this new technique can provide spot resolutions and brightness values that are
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::10a89ec9ef44abbcf4fa1f9b9ab79c40
https://doi.org/10.1116/1.2363406
https://doi.org/10.1116/1.2363406