[time-nuts] thorium transitions

[ghf at hoffmann-hochfrequenz.de]

On usenet, sci.electronics.design,
there just develops a discussion on Thorium transitions that may
be usable for clocks.
I had not yet the time to delve into that.
Unfortunately, s.e.d. has a bad S/N ratio. Too many trolls since not 
moderated.

regards, Gerhard

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On 5/8/24 01:36, John Larkin wrote:
> On Tue, 07 May 2024 12:17:24 -0400, Joe Gwinn <joegwinn at comcast.net>
> wrote:
> 
>> On Tue, 7 May 2024 16:26:27 +0200, Jeroen Belleman
>> <jeroen at nospam.please> wrote:
>> 
>>> On 5/7/24 15:35, Martin Brown wrote:
>>>> On 07/05/2024 06:06, Jan Panteltje wrote:
>>>>> Atomic nucleus excited with laser: a breakthrough after decades


>>>>>    <https://www.sciencedaily.com/releases/2024/04/240429103045.htm>


>>>>>     The 'thorium transition', which has been sought after for 
>>>>> decades,
>>>>>     has now been excited for the first time with lasers.
>>>>>     This paves the way for revolutionary high precision 
>>>>> technologies,
>>>>> including nuclear clocks
>>>> 
>>>> I wonder what the Q value for stimulated nuclear emission is?


>>> They state a centre frequency of roughly 2 PHz and a decay time
>>> of 630s, which would put the Q in the 1e19 ballpark. Prodigious.
>>> No wonder it was hard to find.

>> The Time guys have been looking for this forever, so to speak.

>> It's the only atomic kernel transition with any degree of coupling to
>> electromagnetic radiation.  This will be orders of magnitude better
>> than such as lattice clocks.
>> 
>> There will be a flood of papers.
>> JG

> They aren't tuning to a resonance, but to the difference between two
> close resonances.


The current definition of the second uses something similar: Some
hyperfine resonance of cesium. Normal resonances are in the optical
domain, but hyperfine ones are RF.

In nuclei, normal transitions are in the gamma domain, and
hyperfine ones are in the domain of optics. It's just a change
of scale, if you will.

JB