Re: OT: Atomic nucleus excited with laser: a breakthrough after decades

On 08/05/2024 09:44, Jeroen Belleman wrote:

On 5/8/24 01:36, John Larkin wrote:

On Tue, 07 May 2024 12:17:24 -0400, Joe Gwinn <joegwinn@comcast.net>
wrote:
>

On Tue, 7 May 2024 16:26:27 +0200, Jeroen Belleman
<jeroen@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.
>
Joe Gwinn

>
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.

 Which puts them in the RF frequency domain where counting cycles of the continuous sine reference waveform is relatively easy.
 Likewise for H-maser another favourite local time reference signal.
 

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.

 Although there will be some big practical difficulties counting cycles of a waveform at 8eV which is up into the UV. What is the current highest frequency that a semiconductor divider is capable of accepting?
 I know that there are some optical logic circuits about but how capable are they at near UV light?
 You can't mix this thing down without losing its fidelity. I know how to double optical frequencies but how do you halve or quarter them?