7/15/2023 0 Comments Radium clockThe beam’s wavelength matched that of ion’s 7 s 2 S 1/2 → 6 d 2 D 5/2 quadrupole clock transition. The team then focused a linearly polarized 728-nm laser beam at the trapped atom, with the beam at a 45-degree angle to the trap’s magnetic field. The physicists at the University of California, Santa Barbara (UCSB), USA, began by ablating a single radium-226 ion from a sample of radium chloride and trapping the ion. With further refinements, the clock could make other precise measurements related to fundamental quantum physics. Lett., doi: 10.1103/PhysRevLett.128.033202).īesides being the first timekeeper based on the radioactive metal radium, the research team used its new optical clock to make the first measurement of the ratio of two quantities related to the angular momentum of the electric quadrupole transition within the radium ion. Now, researchers at a US university have built and operated an optical clock containing a single trapped radium-226 ion (Phys. Įxperimental optical clocks-based on atomic transitions that emit visible light instead of microwaves-employ atoms of metallic elements such as ytterbium, strontium and calcium. A team at the University of California, Santa Barbara, USA, will use the radium molecule to search for time-symmetry violation. If you are concerned, don’t obtain a radium watch.A radium atom and polyatomic molecule are held between the electrodes of an ion trap. I make no promises about the safety of this or any guarantees. I hope this helps, but you will have to decide for yourself what your risk tolerance is. For what it’s worth, I’ve kept my radon detector near the watch in this room and the amount of radon detected is extremely low (not quite undetectable - higher than the average in my home, but equivalent with most background levels of radon in the US). (The watch could end up right next to my nose where I’d breathe in gas for hours.)ģ) I store the watch in an open box in a well-ventilated room (that is, near an open window) away from the bedrooms. It’s a special piece.Ģ) I do not sleep with the watch on. I certainly do wear it a few times a month and enjoy it when I do. I decided that it was likely that the risk was low - and this is important - low but not zero.ġ) I don’t wear the watch every day. Obviously this gas is released when the box is opened.īased on this, here’s what I decided for myself. I put my watch in a closed watch box with a radon detector and recoded unsafe levels of radon that built up within the box. ![]() But like I say, there’s not much of it.ģ) Radium decays to radon gas. This radiation does penetrate and go to the bone. Something like 10% of the NRC’s rating of the average annual dose of radiation a person might receive. Comparable to something like two-thirds of the annual radiation you’d receive if you lived in Denver. (Even if it gets thru the watch case, alpha particles won’t go deeper than your skin.)Ģ) The amount of gamma ray radiation is low. And my understanding is that we aren’t seeing a lot of skin cancer on the wrist from this radiation. I do plan to test this with my particular watch at some point. However it’s not clear how much of this is blocked by the case of the watch and going into the skin. So where you may end up may be different.ġ) The amount of alpha particle radiation emitted by the watch is high. FYI I’m not a scientist nor a watch expert. I did a bunch of reading and here is where I netted out for me. I recently obtained a watch with a radium dial. /r/WatchExchange for buying, selling, trading watchesīanner photo courtesy of /u/northscylla Please take a look at our community rules and FAQ before contributing!./r/WatchHorology our sister subreddit for horology, watch appreciation, history, technical discussion and related topics.Simple Questions and Recommendations ThreadĬome hang out in the Official /r/Watches Discord! Our previous Buying Guide thread: Dive Watches Check them outĪpril 2019 State of the Sub Discussion and SummaryĢ1-26 Mar 19 Baselworld 2019 Discussion MegathreadĤ Dec 18 - AMA with Arial Adams & Matt Smith-Johnson for a new LE watch collaboration with Laco. The TAG Heuer subreddit has been reactivated and is now live.Updates to the Buying Guide have begun as well! Please come and suggest watches within the specific budget and style ranges.Let's hear your thoughts on anything relating to this brand! Personal anecdotes, opinions, technical articles, and everything else are all accepted and encouraged. We are in the process of updating our Brand Guides.If you would like to submit a post that deals with fakes in some way, please modmail to discuss before posting. ![]() Replica/counterfeit watch posts and discussion are explicitly forbidden. Please read our community rules and FAQ before contributing! Welcome to /r/Watches, a community for watch & horology discussion.
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