Optical Cesium or maybe Cesium "light"!
Looks like Oscilloquartz is getting ready to sell this commercially!
Will give the 5071A a run for the money!
Reliability should go way up as:
-No electron multiplier
-No ionizer filament
-No state selection magnets
Also all the fiddley bits (laser diodes and photodetectors) are external
to the tube and can be easily updated as needed.
https://www.slideshare.net/ADVAOpticalNetworking/performance-results-of-a
n-optically-pumped-cesium-beam-clock
Cheers,
Corby
Len Cutler was all set to build an optically
pumped Cs beam 20 years ago. Even then, he could get the lasers.
He was only missing one thing: money. HP management never
agreed to fund it. The paper conspicuously omits any spec
on absolute accuracy. The optical pumping does nothing to
improve that AFAIK. It still depends on phase error in the CBT.
The 5071 has a guaranteed accuracy of 10^-12, and is typically
several times better than that.
It is surprising that none of the various makers of the 5071A
ever made an optical version. I wonder what they are thinking
now that someone else has done it.
Rick
On 3/17/2017 7:48 PM, cdelect@juno.com wrote:
Looks like Oscilloquartz is getting ready to sell this commercially!
Will give the 5071A a run for the money!
Reliability should go way up as:
-No electron multiplier
-No ionizer filament
-No state selection magnets
Also all the fiddley bits (laser diodes and photodetectors) are external
to the tube and can be easily updated as needed.
https://www.slideshare.net/ADVAOpticalNetworking/performance-results-of-a
n-optically-pumped-cesium-beam-clock
Cheers,
Corby
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
An Early (~1980?) NS/FEI paper on optically pumped cesium beam tubes:
http://tf.nist.gov/general/pdf/732.pdf
Bruce
On 18 March 2017 at 17:28 "Richard (Rick) Karlquist" <richard@karlquist.com> wrote:
Len Cutler was all set to build an optically
pumped Cs beam 20 years ago. Even then, he could get the lasers.
He was only missing one thing: money. HP management never
agreed to fund it. The paper conspicuously omits any spec
on absolute accuracy. The optical pumping does nothing to
improve that AFAIK. It still depends on phase error in the CBT.
The 5071 has a guaranteed accuracy of 10^-12, and is typically
several times better than that.
It is surprising that none of the various makers of the 5071A
ever made an optical version. I wonder what they are thinking
now that someone else has done it.
Rick
On 3/17/2017 7:48 PM, cdelect@juno.com wrote:
Looks like Oscilloquartz is getting ready to sell this commercially!
Will give the 5071A a run for the money!
Reliability should go way up as:
-No electron multiplier
-No ionizer filament
-No state selection magnets
Also all the fiddley bits (laser diodes and photodetectors) are external
to the tube and can be easily updated as needed.
https://www.slideshare.net/ADVAOpticalNetworking/performance-results-of-a
n-optically-pumped-cesium-beam-clock
Cheers,
Corby
_______________________________________________
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
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and follow the instructions there.
On Sat, Mar 18, 2017 at 2:48 AM, cdelect@juno.com wrote:
Looks like Oscilloquartz is getting ready to sell this commercially!
Two year old deck with a fair amount of overlap, though a few more
engineering diagrams.
Heres to hoping they fit it with an unreliable LCD backlight so
they'll be available as cosmetically defective cheap surplus in the
future. :)
In message 45f89398-9302-80dc-3b9d-690802c466d9@karlquist.com, "Richard (Rick) Karlquist" write
s:
It is surprising that none of the various makers of the 5071A
ever made an optical version. I wonder what they are thinking
now that someone else has done it.
Why would they ?
They had a pretty good gig going with no competition...
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
The NIST-7 was a optically pumped cesium beam, and a pre-cursor to the
fountain clocks. There should be a bunch of papers on it.
If you look on the picture from wikipedia:
https://en.wikipedia.org/wiki/NIST-7
You can see the optical bench on top of the electronics rack.
The modern books go into length about the issues of laser pumping and
detection, so there is plenty of material to work from.
The A magnet being replaced by the A laser will for the same flow from
the cesium oven produce twice as much atoms and thus improve signal to
noise. I also expect that the optical detection does not experience the
same wear mechanisms as the traditional setup. Laser wear is however a
concern, but easier to handle.
I am however somewhat wondering about if we will see this coming out of
Oscilloquartz. We will see.
Cheers,
Magnus
On 03/18/2017 09:05 AM, Bruce Griffiths wrote:
An Early (~1980?) NS/FEI paper on optically pumped cesium beam tubes:
http://tf.nist.gov/general/pdf/732.pdf
Bruce
On 18 March 2017 at 17:28 "Richard (Rick) Karlquist" <richard@karlquist.com> wrote:
Len Cutler was all set to build an optically
pumped Cs beam 20 years ago. Even then, he could get the lasers.
He was only missing one thing: money. HP management never
agreed to fund it. The paper conspicuously omits any spec
on absolute accuracy. The optical pumping does nothing to
improve that AFAIK. It still depends on phase error in the CBT.
The 5071 has a guaranteed accuracy of 10^-12, and is typically
several times better than that.
It is surprising that none of the various makers of the 5071A
ever made an optical version. I wonder what they are thinking
now that someone else has done it.
Rick
On 3/17/2017 7:48 PM, cdelect@juno.com wrote:
Looks like Oscilloquartz is getting ready to sell this commercially!
Will give the 5071A a run for the money!
Reliability should go way up as:
-No electron multiplier
-No ionizer filament
-No state selection magnets
Also all the fiddley bits (laser diodes and photodetectors) are external
to the tube and can be easily updated as needed.
https://www.slideshare.net/ADVAOpticalNetworking/performance-results-of-a
n-optically-pumped-cesium-beam-clock
Cheers,
Corby
_______________________________________________
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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and follow the instructions there.
I am in the same frame of mind had the market, so no need to evolve. But
also it seems the business segment is so small its unclear that there is a
good business case to build them.These days if its not $B little interest.
Chuckle.
Hp dumped cesiums and test equipment and then symetricom was purchased by
Microsemi. Pretty strange. All in all in the timing market the players seem
to be all but gone.
Regards
Paul
WB8TSL
On Sat, Mar 18, 2017 at 4:56 AM, Poul-Henning Kamp phk@phk.freebsd.dk
wrote:
In message 45f89398-9302-80dc-3b9d-690802c466d9@karlquist.com, "Richard
(Rick) Karlquist" write
s:
It is surprising that none of the various makers of the 5071A
ever made an optical version. I wonder what they are thinking
now that someone else has done it.
Why would they ?
They had a pretty good gig going with no competition...
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
Did take a look at the various papers. The older Osciliquartz document does
overlap the new one. But the old one actually supplies more details. Good
reads.
It is interesting that the major consumable components like laser diodes
are all external. So what is the true life of the unit. Pretty curious and
suspect its far beyond 10 years.
Also power consumption is 35 watts or a running savings of 30% over the
5071.
Pretty sure we will see these on ebay in the next few years.... NOT
Regards
Paul
WB8TSL
On Sat, Mar 18, 2017 at 10:32 AM, paul swed paulswedb@gmail.com wrote:
I am in the same frame of mind had the market, so no need to evolve. But
also it seems the business segment is so small its unclear that there is a
good business case to build them.These days if its not $B little interest.
Chuckle.
Hp dumped cesiums and test equipment and then symetricom was purchased by
Microsemi. Pretty strange. All in all in the timing market the players seem
to be all but gone.
Regards
Paul
WB8TSL
On Sat, Mar 18, 2017 at 4:56 AM, Poul-Henning Kamp phk@phk.freebsd.dk
wrote:
In message 45f89398-9302-80dc-3b9d-690802c466d9@karlquist.com,
"Richard (Rick) Karlquist" write
s:
It is surprising that none of the various makers of the 5071A
ever made an optical version. I wonder what they are thinking
now that someone else has done it.
Why would they ?
They had a pretty good gig going with no competition...
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by
incompetence.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
On 3/18/2017 3:13 AM, Magnus Danielson wrote:
The NIST-7 was a optically pumped cesium beam, and a pre-cursor to the
fountain clocks. There should be a bunch of papers on it.
I am however somewhat wondering about if we will see this coming out of
Oscilloquartz. We will see.
NIST-7 has a reversible beam, which cancels out end to end phase
error in the CBT. That works in terms of being a frequency standard,
but not for a clock, because you don't have continuous operation.
NIST-7 is also much longer than the 5071A or the Oscilloquartz offering.
So they are not really comparable beyond sharing optical pumping.
Rick
Rick,
On 03/18/2017 05:32 PM, Richard (Rick) Karlquist wrote:
On 3/18/2017 3:13 AM, Magnus Danielson wrote:
The NIST-7 was a optically pumped cesium beam, and a pre-cursor to the
fountain clocks. There should be a bunch of papers on it.
I am however somewhat wondering about if we will see this coming out of
Oscilloquartz. We will see.
NIST-7 has a reversible beam, which cancels out end to end phase
error in the CBT. That works in terms of being a frequency standard,
but not for a clock, because you don't have continuous operation.
NIST-7 is also much longer than the 5071A or the Oscilloquartz offering.
So they are not really comparable beyond sharing optical pumping.
I think you misunderstood my comment quite a bit.
It is merely a suggestion to find more articles on the topic of optical
pumpning beams.
One problem with the NIST-7 is also the poor S/N. It was used more for
frequency than continuous clock, but free-wheeling on commercial clocks
helps for the ensamble behavior.
Cheers,
Magnus