Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Bob Camp
of those that lead the > development. > This link has the basics: http://tf.nist.gov/general/pdf/1957.pdf. I want > two. > > Thomas Knox > > > 1-303-554-0307 > >> Date: Sun, 5 May 2013 06:59:12 -0700 >> From: jim...@earthlink.net >> To: t

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Bob Camp
Hi There were a number of trapped ion papers back in the 70's and 80's. The NIST effort to transition from Cs to an ion standard was well underway by the mid 1980's. Bob On May 5, 2013, at 5:49 PM, Magnus Danielson wrote: > Hi Tom, > > On 05/05/2013 11:33 PM, Tom Knox wrote: >> The idea of

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Jim Lux
On 5/5/13 2:49 PM, Magnus Danielson wrote: I have all the Hg-199 and Hg-202 I need for a few clocks, but in it's natural mixture. Don't feel like building a separation facility... Use the quadrupole system you're using as a trap as a mass-spec to do the separation. __

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Magnus Danielson
Hi Tom, On 05/05/2013 11:33 PM, Tom Knox wrote: The idea of a Mercury Ion clocks started about 2000 and from about 2005 until recently has held the title of worlds most accurate clock. Approx 1 sec per 1.6 billion years the last I heard. At the heart is a single trapped mercury atom. Jim Bergq

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Tom Knox
development. This link has the basics: http://tf.nist.gov/general/pdf/1957.pdf. I want two. Thomas Knox 1-303-554-0307 > Date: Sun, 5 May 2013 06:59:12 -0700 > From: jim...@earthlink.net > To: time-nuts@febo.com > Subject: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs >

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Magnus Danielson
On 05/05/2013 11:14 PM, Jim Lux wrote: On 5/5/13 11:45 AM, Magnus Danielson wrote: Hi Jim, On 05/05/2013 07:33 PM, Jim Lux wrote: On 5/5/13 10:05 AM, Magnus Danielson wrote: They have been targeting this goal for a very long time. Several interesting papers is to be found at PTTI, NIST etc.

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Jim Lux
On 5/5/13 11:45 AM, Magnus Danielson wrote: Hi Jim, On 05/05/2013 07:33 PM, Jim Lux wrote: On 5/5/13 10:05 AM, Magnus Danielson wrote: They have been targeting this goal for a very long time. Several interesting papers is to be found at PTTI, NIST etc. Yeah.. some years (6 or 7?) ago, John

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Magnus Danielson
On 05/05/2013 09:28 PM, Poul-Henning Kamp wrote: In message<20130505205257.8497f166abb1e49186953...@kinali.ch>, Attila Kinali w rites: I also have never seen a H gas cell standard, probably for the same reason of needing UV light. Hydrogen is very hard to contain. The way you *filter* hydrog

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Magnus Danielson
Hi Poul-Henning, On 05/05/2013 08:29 PM, Poul-Henning Kamp wrote: In message<51867df4.4010...@karlquist.com>, "Richard (Rick) Karlquist" writes: BTW, it is important to understand that the architecture is the key factor, not the flavor of atom. Well, somewhat. Some flavours of atoms don't w

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Poul-Henning Kamp
In message <20130505205257.8497f166abb1e49186953...@kinali.ch>, Attila Kinali w rites: >I also have never seen a H gas cell standard, probably for the same reason >of needing UV light. Hydrogen is very hard to contain. The way you *filter* hydrogen is to press it through a palladium film, and th

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Attila Kinali
On Sun, 05 May 2013 18:29:53 + "Poul-Henning Kamp" wrote: > In message <51867df4.4010...@karlquist.com>, "Richard (Rick) Karlquist" > writes: > > >BTW, it is important to understand that > >the architecture is the key factor, not the flavor of atom. > > Well, somewhat. > > Some flavours o

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Magnus Danielson
Hi Jim, On 05/05/2013 07:33 PM, Jim Lux wrote: On 5/5/13 10:05 AM, Magnus Danielson wrote: They have been targeting this goal for a very long time. Several interesting papers is to be found at PTTI, NIST etc. Yeah.. some years (6 or 7?) ago, John Prestage had a prototype of the physics packa

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Poul-Henning Kamp
In message <51867df4.4010...@karlquist.com>, "Richard (Rick) Karlquist" writes: >BTW, it is important to understand that >the architecture is the key factor, not the flavor of atom. Well, somewhat. Some flavours of atoms don't work with some architectures, so for most of the stuff in reach for u

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Jim Lux
On 5/5/13 10:01 AM, Magnus Danielson wrote: Hi Jim, On 05/05/2013 03:59 PM, Jim Lux wrote: On 5/5/13 1:48 AM, Magnus Danielson wrote: The above is a summary of things collected from a variety of sources, but I think this coarse walk-through of issues gives some insight as to what issues pops u

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Jim Lux
On 5/5/13 10:05 AM, Magnus Danielson wrote: On 05/05/2013 06:50 PM, Jim Lux wrote: On 5/5/13 8:42 AM, Richard (Rick) Karlquist wrote: At HP in the 1990's, Len Cutler's group built some experimental mercury ion standards for USNO (IIRC). They were of the trapped ion type. BTW, it is important to

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Magnus Danielson
On 05/05/2013 06:50 PM, Jim Lux wrote: On 5/5/13 8:42 AM, Richard (Rick) Karlquist wrote: At HP in the 1990's, Len Cutler's group built some experimental mercury ion standards for USNO (IIRC). They were of the trapped ion type. BTW, it is important to understand that the architecture is the key

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Magnus Danielson
Hi Jim, On 05/05/2013 03:59 PM, Jim Lux wrote: On 5/5/13 1:48 AM, Magnus Danielson wrote: The above is a summary of things collected from a variety of sources, but I think this coarse walk-through of issues gives some insight as to what issues pops up where and the milage vary a lot within each

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Jim Lux
On 5/5/13 8:42 AM, Richard (Rick) Karlquist wrote: At HP in the 1990's, Len Cutler's group built some experimental mercury ion standards for USNO (IIRC). They were of the trapped ion type. BTW, it is important to understand that the architecture is the key factor, not the flavor of atom. When p

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Richard (Rick) Karlquist
At HP in the 1990's, Len Cutler's group built some experimental mercury ion standards for USNO (IIRC). They were of the trapped ion type. BTW, it is important to understand that the architecture is the key factor, not the flavor of atom. When people say rubidium is inferior to cesium, they reall

Re: [time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Bob Camp
Hi Mercury was tried very early on as a vapor standard. They had some significant problems with it in the 1950's. It's not surprising that after 60 years somebody might want to take another swing at it. Bob On May 5, 2013, at 9:59 AM, Jim Lux wrote: > On 5/5/13 1:48 AM, Magnus Danielson wrot

[time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

2013-05-05 Thread Jim Lux
On 5/5/13 1:48 AM, Magnus Danielson wrote: On 05/05/2013 10:05 AM, Attila Kinali wrote: On Sat, 4 May 2013 12:36:20 -0700 "Tom Van Baak (lab)" wrote: Rule of thumb: quartz is best short term, Rb or H-maser mid-term, and Cs by far the best long-term. Ah.. so it's a fundamental limitation. An