Re: [time-nuts] PTTI 2012, part 2

2012-12-05 Thread Mark Kahrs
Sent: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes

Re: [time-nuts] PTTI 2012, part 2

2012-12-05 Thread Magnus Danielson
On 12/05/2012 03:26 PM, Mark Kahrs wrote: I couldn't resist and did a little reading. So, the MIT Flea has MOT cells? That would seem to be the deal breaker to me. The rest is just plumbing. And smoke and mirrors. While participating at the NIST TF seminars, one of the tours was in fact a

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bob Camp
Hi I went through a similar process quite a while ago. The dimensions of the actual fountain can be quite small. One could make one the size of a shoe box and still have it perform quite well. Bob On Dec 3, 2012, at 2:07 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread paul swed
OK now that I am setting out to build one. Would the challenge for a amateur be that the components you build with are basically dirty. Some how on the copper pipe it would need to be clean and then brazed I might guess. All of that makes for a dirty element. To the vacuum. I used to make vaccuum

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bill Dailey
I used to work on oxygen clean systems... that cleaning is done primarily with liquid freon (R-113 and ultrasound - may be hard to get now). The Vacuum stuff is expensive but off the shelf. The complicated part to me is the lasers and microwave... in addition to the super-stable oscillator you

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Poul-Henning Kamp
In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes: If you look at the papers on portable rubidium fountains they are significantly bigger than a shoebox (65 cm). Diameter is controlled by dispersion of the launched atoms (=recovery rate)

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bob Camp
- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bill Dailey
AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes: If you look at the papers on portable rubidium fountains

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread paul swed
...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bob Camp
[mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Tuesday, December 04, 2012 9:49 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] PTTI 2012, part 2 Basements the key. So for me bigger is better. Heck if its a rack thats ok. It gets interesting

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bill Dailey
; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes: If you look at the papers on portable rubidium fountains they are significantly bigger than a shoebox (65 cm). Diameter

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bruce Griffiths
...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Don Latham
Sent: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes: If you look at the papers

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Poul-Henning Kamp
In message 50be4f1d.7020...@xtra.co.nz, Bruce Griffiths writes: The lasers arent that difficult to make or expensive if one adopts a modified Littrow ECDL configuration. Laser diodes without AR coatings have been used successfully in such lasers. Low noise current sources and close

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread EWKehren
To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes: If you look at the papers on portable rubidium fountains

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bill Dailey
-Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bob Camp
Hi A few kilometers of optical fiber should do the trick. Servo the fiber temperature to keep things locked up. Bob On Dec 4, 2012, at 4:17 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message 50be4f1d.7020...@xtra.co.nz, Bruce Griffiths writes: The lasers arent that

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bob Camp
and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes: If you look at the papers on portable rubidium fountains they are significantly bigger than

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread Bob Camp
-Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message

Re: [time-nuts] PTTI 2012, part 2

2012-12-04 Thread EWKehren
: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes: If you look

Re: [time-nuts] PTTI 2012, part 2

2012-12-03 Thread Tom Van Baak
Continuing from previous posting... Still, there are always a number of talks of more general interest to us time nuts. In the next few postings I'll give more details on a couple of topics: - Neutrino time-of-flight update Last years' faster-than-light neutrino fiasco is now old news, but

Re: [time-nuts] PTTI 2012, part 2

2012-12-03 Thread Poul-Henning Kamp
In message AB5B0278225B4BD483382A39E6834203@pc52, Tom Van Baak writes: - USNO rubidium fountains While many national labs have developed cesium fountains (for accuracy), USNO has been gradually building rubidium fountain clocks (for stability) and 4 of them are now fully operational.