Team of physicists repeats tvb Project GREAT
https://www.nature.com/articles/s41567-017-0042-3
At substantially more expense, and with an experimental lattice clock,
and a lot more references..
On Wed, February 14, 2018 7:06 pm, jimlux wrote:
At substantially more expense, and with an experimental lattice clock,
Does that schematic figure in the paper imply that the "transportable"
strontium and ytterbium clocks are built into trailers instead of the
traditional rack enclosure?
Actually now that I look more closely it looks like maybe two trailers.
Doesn't seem like something that Jim is going to be flying any time soon.
--
Chris Caudle
On Feb 14, 2018 19:47, "Chris Caudle" chris@chriscaudle.org wrote:
On Wed, February 14, 2018 7:06 pm, jimlux wrote:
At substantially more expense, and with an experimental lattice clock,
Does that schematic figure in the paper imply that the "transportable"
strontium and ytterbium clocks are built into trailers instead of the
traditional rack enclosure?
Actually now that I look more closely it looks like maybe two trailers.
Doesn't seem like something that Jim is going to be flying any time soon.
Yes. From the Nature article text:
"The transportable 87Sr lattice clock is (compared with laboratory clocks)
designed to be compact, with robust optical parts12
https://www.nature.com/articles/s41567-017-0042-3#ref-CR12. The physics
package is less than 0.6 m3 in size, and we use laser breadboards with
mechanical stress-resistant fibre couplers21
https://www.nature.com/articles/s41567-017-0042-3#ref-CR21. All
components except the reference cavity of the interrogation laser are
rigidly mounted in a car trailer (size 2.2 m × 3 m × 2.2 m), and vibration
isolation is provided by rubber dampers. The trailer interior is
temperature stabilized, while the small volume of the trailer hinders air
exchange and generates hot spots with more than 10 K temperature rise.
However, the optics and the physics package are placed apart and shielded
from these and are stable to within 0.4 K after an initial temperature rise
of about 1 K. The transportable ultrastable reference cavity for the clock
interrogation lasers is rigidly mounted to endure transport12
https://www.nature.com/articles/s41567-017-0042-3#ref-CR12. It was placed
next to the trailer to avoid its performance being degraded by vibrations
induced in the trailer’s air conditioning system. The vibration amplitudes
in the trailer are a factor of ten larger than under typical laboratory
conditions, leading to a corresponding increase in clock instability. A
reference resonator with lower acceleration sensitivity or an active
feed-forward system may in the future remedy this inconvenience22
https://www.nature.com/articles/s41567-017-0042-3#ref-CR22."
Cheers,
Tim
--
Chris Caudle
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There's a photo here:
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.07360
Cheers
Michael
On Thu, 15 Feb 2018 at 1:47 pm, Chris Caudle chris@chriscaudle.org wrote:
On Wed, February 14, 2018 7:06 pm, jimlux wrote:
At substantially more expense, and with an experimental lattice clock,
Does that schematic figure in the paper imply that the "transportable"
strontium and ytterbium clocks are built into trailers instead of the
traditional rack enclosure?
Actually now that I look more closely it looks like maybe two trailers.
Doesn't seem like something that Jim is going to be flying any time soon.
--
Chris Caudle
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.
Sorry, missed the last character in the URL:
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.073601
On Thu, 15 Feb 2018 at 4:42 pm, Michael Wouters michaeljwouters@gmail.com
wrote:
There's a photo here:
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.07360
Cheers
Michael
On Thu, 15 Feb 2018 at 1:47 pm, Chris Caudle chris@chriscaudle.org
wrote:
On Wed, February 14, 2018 7:06 pm, jimlux wrote:
At substantially more expense, and with an experimental lattice clock,
Does that schematic figure in the paper imply that the "transportable"
strontium and ytterbium clocks are built into trailers instead of the
traditional rack enclosure?
Actually now that I look more closely it looks like maybe two trailers.
Doesn't seem like something that Jim is going to be flying any time soon.
--
Chris Caudle
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.
Well it will fit in a C-130 or any commercial cargo plane by the looks of the trailer. So it could be a flying clock.
Content by Scott
Typos by Siri
On Feb 15, 2018, at 1:02 AM, Michael Wouters michaeljwouters@gmail.com wrote:
Sorry, missed the last character in the URL:
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.073601
On Thu, 15 Feb 2018 at 4:42 pm, Michael Wouters michaeljwouters@gmail.com
wrote:
There's a photo here:
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.07360
Cheers
Michael
On Thu, 15 Feb 2018 at 1:47 pm, Chris Caudle chris@chriscaudle.org
wrote:
On Wed, February 14, 2018 7:06 pm, jimlux wrote:
At substantially more expense, and with an experimental lattice clock,
Does that schematic figure in the paper imply that the "transportable"
strontium and ytterbium clocks are built into trailers instead of the
traditional rack enclosure?
Actually now that I look more closely it looks like maybe two trailers.
Doesn't seem like something that Jim is going to be flying any time soon.
--
Chris Caudle
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.
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.
On 2/14/18 6:46 PM, Chris Caudle wrote:
On Wed, February 14, 2018 7:06 pm, jimlux wrote:
At substantially more expense, and with an experimental lattice clock,
Does that schematic figure in the paper imply that the "transportable"
strontium and ytterbium clocks are built into trailers instead of the
traditional rack enclosure?
Actually now that I look more closely it looks like maybe two trailers.
Doesn't seem like something that Jim is going to be flying any time soon.
nor will tvb's brother-in-law be wearing it as a wristwatch
http://www.leapsecond.com/pages/atomic-bill/
On 2/14/18 6:51 PM, Tim Lister wrote:
On Feb 14, 2018 19:47, "Chris Caudle" chris@chriscaudle.org wrote:
On Wed, February 14, 2018 7:06 pm, jimlux wrote:
At substantially more expense, and with an experimental lattice clock,
Does that schematic figure in the paper imply that the "transportable"
strontium and ytterbium clocks are built into trailers instead of the
traditional rack enclosure?
Actually now that I look more closely it looks like maybe two trailers.
Doesn't seem like something that Jim is going to be flying any time soon.
Yes. From the Nature article text:
"The transportable 87Sr lattice clock is (compared with laboratory clocks)
designed to be compact, with robust optical parts12
https://www.nature.com/articles/s41567-017-0042-3#ref-CR12. The physics
package is less than 0.6 m3 in size, and we use laser breadboards with
mechanical stress-resistant fibre couplers21
https://www.nature.com/articles/s41567-017-0042-3#ref-CR21. All
components except the reference cavity of the interrogation laser are
rigidly mounted in a car trailer (size 2.2 m × 3 m × 2.2 m), and vibration
isolation is provided by rubber dampers. The trailer interior is
temperature stabilized, while the small volume of the trailer hinders air
exchange and generates hot spots with more than 10 K temperature rise.
However, the optics and the physics package are placed apart and shielded
from these and are stable to within 0.4 K after an initial temperature rise
of about 1 K. The transportable ultrastable reference cavity for the clock
interrogation lasers is rigidly mounted to endure transport12
https://www.nature.com/articles/s41567-017-0042-3#ref-CR12. It was placed
next to the trailer to avoid its performance being degraded by vibrations
induced in the trailer’s air conditioning system. The vibration amplitudes
in the trailer are a factor of ten larger than under typical laboratory
conditions, leading to a corresponding increase in clock instability. A
reference resonator with lower acceleration sensitivity or an active
feed-forward system may in the future remedy this inconvenience22
https://www.nature.com/articles/s41567-017-0042-3#ref-CR22."
We have discussed the desirability of suitable caves for operation of
high quality clocks many times on this list.
Clearly this is another instance.
With respect to flying such things in space - this is the continual
challenge - DSAC (the trapped mercury ion clock) was a couple of benches
in a special time keeping lab when I first saw it, oh, a decade ago?.
It will fly later this year and it's probably about the size of an
airplane carry-on.
https://www.jpl.nasa.gov/missions/deep-space-atomic-clock-dsac/
Cold Atom Laboratory basically takes several optical benches operated by
a team of post-docs that makes Bose Einstein Condensates (BEC) and turns
it into a box the size of a dorm refrigerator that goes "ping" when you
press a button and makes a BEC (in either Rb or K, as you choose).
https://coldatomlab.jpl.nasa.gov/mission/
Just as a rule of thumb, I've found that it takes about 10-20 times the
cost to get from "benchtop prototype"(TRL 5) to "flyable unit" (TRL 6),
as it cost to get from idea to benchtop prototype.
Hi
On Feb 15, 2018, at 9:03 AM, jimlux jimlux@earthlink.net wrote:
On 2/14/18 6:51 PM, Tim Lister wrote:
On Feb 14, 2018 19:47, "Chris Caudle" chris@chriscaudle.org wrote:
On Wed, February 14, 2018 7:06 pm, jimlux wrote:
At substantially more expense, and with an experimental lattice clock,
Does that schematic figure in the paper imply that the "transportable"
strontium and ytterbium clocks are built into trailers instead of the
traditional rack enclosure?
Actually now that I look more closely it looks like maybe two trailers.
Doesn't seem like something that Jim is going to be flying any time soon.
Yes. From the Nature article text:
"The transportable 87Sr lattice clock is (compared with laboratory clocks)
designed to be compact, with robust optical parts12
https://www.nature.com/articles/s41567-017-0042-3#ref-CR12. The physics
package is less than 0.6 m3 in size, and we use laser breadboards with
mechanical stress-resistant fibre couplers21
https://www.nature.com/articles/s41567-017-0042-3#ref-CR21. All
components except the reference cavity of the interrogation laser are
rigidly mounted in a car trailer (size 2.2 m × 3 m × 2.2 m), and vibration
isolation is provided by rubber dampers. The trailer interior is
temperature stabilized, while the small volume of the trailer hinders air
exchange and generates hot spots with more than 10 K temperature rise.
However, the optics and the physics package are placed apart and shielded
from these and are stable to within 0.4 K after an initial temperature rise
of about 1 K. The transportable ultrastable reference cavity for the clock
interrogation lasers is rigidly mounted to endure transport12
https://www.nature.com/articles/s41567-017-0042-3#ref-CR12. It was placed
next to the trailer to avoid its performance being degraded by vibrations
induced in the trailer’s air conditioning system. The vibration amplitudes
in the trailer are a factor of ten larger than under typical laboratory
conditions, leading to a corresponding increase in clock instability. A
reference resonator with lower acceleration sensitivity or an active
feed-forward system may in the future remedy this inconvenience22
https://www.nature.com/articles/s41567-017-0042-3#ref-CR22."
We have discussed the desirability of suitable caves for operation of high quality clocks many times on this list.
Clearly this is another instance.
Search the archives for “swimming pool full of mercury” for one go around on this.
Bob
With respect to flying such things in space - this is the continual challenge - DSAC (the trapped mercury ion clock) was a couple of benches in a special time keeping lab when I first saw it, oh, a decade ago?. It will fly later this year and it's probably about the size of an airplane carry-on.
https://www.jpl.nasa.gov/missions/deep-space-atomic-clock-dsac/
Cold Atom Laboratory basically takes several optical benches operated by a team of post-docs that makes Bose Einstein Condensates (BEC) and turns it into a box the size of a dorm refrigerator that goes "ping" when you press a button and makes a BEC (in either Rb or K, as you choose).
https://coldatomlab.jpl.nasa.gov/mission/
Just as a rule of thumb, I've found that it takes about 10-20 times the cost to get from "benchtop prototype"(TRL 5) to "flyable unit" (TRL 6), as it cost to get from idea to benchtop prototype.
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.