The database is now complete!

Folks,

This is exciting times for the database we’ve been trying to put online during the past 2 years. In the process, we’ve had severe failures, major redesigns and several updates. Nevertheless, our efforts are proven fruitful and we are now pleased to announce the complete set of nuclear magnetic dipole and electric quadrupole moments to the community. As a bonus, magnetic moments of elementary particles are now featured in the database. Also, we have tried to modernize the frontend by adding an alternative view, using a helix-like ladder that symbolizes both the expansion of our site and the future of nuclear data collection and archiving.

Our database can be directly found in this link: http://magneticmoments.info/data 

The data have been collected from fully electronic and printed sources. Prof. N.J. Stone’s milestone paper was used as the major source, but our database is extended gradually to include more information, such as DOI keys and non-evaluated data as they appear in this blog, and elsewhere, for the convenience of the fellow researchers.

We welcome comments, corrections, suggestions and of course DONATIONS 🙂 This server is a fully private project without any financial support other than our pocket. So, if you think it’s interesting, send us an email and we can tell you how you can help our site grow. In any case, thanks for visiting!

2 Comments

N.D. CookJanuary 20th, 2012 at 3:23 am

Dear Theo,

I have previously relied on Nick Stone’s compilation, but I am happy to have found your website with active updating of nuclear magnetic moments. This is why the internet is so wonderful, so I wish you luck in drawing attention to this valuable resource!
Maybe anyone interested in magnetic moments already understands this, but what I think is still missing from your website is indication of the importance of specifically the magnetic moments for a proper understanding of nuclear structure.

On the one hand, the textbooks typically show the Schmidt Lines, together with data points indicating that most experimental values lie between the upper and lower values. Already by the early 1950s, the Schmidt lines clearly indicated that the independent-particle model was more-or-less valid, but there has been surprisingly little progress since then. Because the modern experimental data are precise up to 7 or 8 digits and classical electromagnetic theory is well understood, explanation of nuclear magnetic moments SHOULD be (but is not yet) an area where discrepancies between experiment and theory might be discussed with some clarity!

On the other hand, theorists who calculate nuclear magnetic moments typically use model parameters that are adjusted to reproduce the experimental data. Adjusting the parameters of the nuclear models is entirely normal practice, but such modeling gives the impression that the magnetic moments are understood quantitatively, whereas the truth is considerably less optimistic. That “hard reality” is not often acknowledged, I would say, but last year a Chinese physics journal, SCIENCE CHINA, was rather straight-forward in stating the continuing problems in explaining nuclear magnetic moments.

http://esciencenews.com/articles/2010/12/23/nuclear.magnetic.moments

In explaining why they were to publish a Special Issue devoted to nuclear moments, the Editors noted that:
“the extension of these [nuclear] models to the study of nuclear magnetic moments is quite limited and unsatisfactory. The magnetic dipole moments of most atomic nuclei throughout the periodic table still remain unexplained and the under-lying physics mechanism is not fully understood….”

And, among the invited reviews of theoretical work that were eventually published, Akito Arima went through the usual explanation of the Schmidt lines, and even cited the good agreement between experiment and theory for a few selected nuclei from his own work published in…. 1954!

I would guess that you are not interested in getting into abstruse theoretical discussions on your web-site, but I think some indication of the current lack of theoretical understanding of nuclear magnetic moments would indicate why nuclear moments are indeed an important topic!

Cheers
Norman

N.D.Cook

TheoJanuary 24th, 2012 at 10:47 pm

Dear Norman,

I am really happy the first comment I have officially received about this blog is yours. Your words have made me really happy. Thank you deeply.

I would like to promote your comment to a real post, especially because you outlined the importance of the magnetic moments to a level I can not exceed. My intentions when I first had the idea of this website was to explore the possibilities of the web and use it as a means to provide all this significant information available in printed format in a consistent online scheme. The project has not been easy, but now we are in a good track. My small group has worked hard and we are proud to have this first version running at full speed. The second version of the database will be completed by summer and will be in the style of nudat, including searchable fields and fancy stuff.

The road to “success” has been a lot harder than it may seem. Requests to official channels for help and support have not been successful, but my dream to expose these important sets of data to my fellow researchers has been persistent. A private server costs some money, but the cost is nothing compared to the endless hours we have spent to gather all data, check them and make them available.

Magnetic moments have been a good companion for me for several years now and I hope they will be for many more still. Nuclear structure can drain really important information from magnetic moments, but as you said, I am not sure if many people in this business realize their significance to the physics of the nucleus. For some, a magnetic moments has always been just a Z/A value. 🙂 Quite untrue, however, I have met people taking such a stand against magnetic moments. On the other hand, many theorists have encouraged me in the process and I would like to grab the opportunity and thank them all through this reply. I hope the database will be useful for them.

My plans are to expand the database and make it better. I have no time to go through an evaluation of all these data. At least not at the moment, as I am fighting for tenure. However, the XUNDL database has been a good role model for magneticmoments.info and I will be quite happy if we could reach its level of usability and simplicity.

Thanks again for your warm comments. As I said at the beginning I will promote your comment to a real post so that people visiting the blog can read a strong argument in favor of magnetic moments and their significance to nuclear physics. Also, I would welcome more comments and suggestions regarding the improvement of the website etc.

All the best,
Theo

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