From awootten at nrao.edu Mon Jul 5 10:29:05 2004 From: awootten at nrao.edu (Al Wootten) Date: Mon, 05 Jul 2004 10:29:05 -0400 Subject: [asac]ASAC Telecon WEDNESDAY 7 July Message-ID: <40E965B1.2010903@nrao.edu> Folks Owing to the holiday in the U.S. and scheduling of the JAO/IPT meeting at the usual meeting time, the ASAC telecon has been moved back one day to Wednesday at the usual time of day. ALMA Science Advisory Committee Draft Agenda for ASAC Telecon Wednesday 7 July 2004 Conference Date: 2004-July-07 (Wednesday) Here's the dial-in information for the telecon: CALL TIME: 1030 am EDT or 14:30 UT CALL DATE: 7-July-2004 (Wednesday) DURATION: 1 hr * USA Number: 877-874-1919 * Outside USA Number: +1-203-320-9891 NOTE NEW NUMBER * Passcode: 185064 * Leader: Al Wootten Agenda: http://www.cv.nrao.edu/~awootten/mmaimcal/asac/asacjul04agenda.html Clear skies, Al From awootten at nrao.edu Thu Jul 8 10:39:12 2004 From: awootten at nrao.edu (Al Wootten) Date: Thu, 08 Jul 2004 10:39:12 -0400 Subject: [asac][Fwd: A major change request has received final approval] Message-ID: <40ED5C90.1010902@nrao.edu> Folks, For your information...H2D+ will now be accessible to ALMA. For the full discussion, follow the link in almaedm. I've added the final few, listing performance expectations, for your information. Al -------- Original Message -------- Subject: A major change request has received final approval Date: Wed 07 Jul 2004 21:48:48 -0700 From: almaedm at nrao.edu To: Distribution at orval.tuc.nrao.edu A major change request that you authored, were informed of, were a reviewer for, or issued a decision on has been approved. http://almaedm.tuc.nrao.edu/forums/alma/dispatch.cgi/changereq/showFolder/100225/def/def/582781 ___________________________________________________________ Forum: CRE - Change Requests Entry: 81. (modified) From: Al Wootten Date: 2004-03-24 10:56 Workflow state: approved - major cr (Change Request Process) Subj: Request to extend upper frequency limit on Band 7 CRE Number : ALMA-40.02.07.00-003-A-CRE Description : The upper frequency edge of Band 7 is now 370 GHz. An increase of this edge to 373 GHz is requested. As with other Band extensions, performance need not be guaranteed in this extension, for which the atmosphere has poor transmission. Author: awootten Date decision required: 2004-04-01 09:00 Name of supervisor who authorized the submittal of this change request: Al Wootten Entry: 81.8. From: Gie Han Tan Date: 2004-05-10 06:21 Subj: Follow up on CCB meeting of 2004-04-28 In a further discussion with the Band 7 cartridge group at IRAM it has been agreed that they will investigate to what extent the Band 7 upper frequency limit can be extended with guaranteed specs and at no extra costs. Spec items that have been identified to detoriate above 370 GHz are Rx noise temperature and image rejection ratio. The possibility of other specs detoriating above 370 GHz will be investigated. For the noise temperature a reduced noise spec of 300 K between 370 and 373 Ghz has been tentatively proposed by IRAM. IRAM will do this further investigation in June '04, after their PDR. ------------------------------------- Entry: 81.9. From: Bill Shillue Date: 2004-06-04 10:40 Subj: Comments from B. Shillue Since this change requires the first LO reference frequency to change from 94.3-120.7 to 94.3-121.7, it changes the photomixer specification and the laser synthesizer and microwave synthesizer frequency coverage requirement. These are all small changes to specs only, the instrumentation will be expected to cover the frequency range in any case. ------------------------------------- Entry: 81.10. From: Christoph Haupt Date: 2004-07-01 00:49 Subj: Response by GHT via email on 2004-06-30 Dear Dick / Christoph, After consultation with IRAM, I can confirm that the ALMA Band 7 upper frequency limit can be increased from 370 GHz to 373 GHz. The receiver noise temperature limit over this extended band, 370 - 373 GHz, will be 300 K. The limit for image rejection ratio over this band will be 7 dB instead of 10 dB. First LO coverage over this extended range should according to Charles be no problem. Last but not least, IRAM agrees to these extended specs without any cost increase. In the next update of the Band 7 cartridge technical specification this change will be incoporated. Best regards, Gie Han From awootten at nrao.edu Thu Jul 8 18:55:06 2004 From: awootten at nrao.edu (Al Wootten) Date: Thu, 08 Jul 2004 18:55:06 -0400 Subject: [asac]Inclusion of 90d phase switching Message-ID: <40EDD0CA.3000503@nrao.edu> Folks Another approval we have sought has been approved. Al -------- Original Message -------- Subject: Forum reply from Stacy Oliver Date: Wed 07 Jul 2004 21:52:08 -0700 From: soliver at nrao.edu To: awootten at nrao.edu http://almaedm.tuc.nrao.edu/forums/alma/dispatch.cgi/changereq/showFolder/100269/def/def/1b7c Stacy Oliver entered a reply to one of your SiteScape Forum entries. Forum Name: CRE - Change Requests Original Entry: Inclusion of 90d phase switching in the ALMA first LO New Reply: Approved by CCB This change request was approved by the CCB at the 2004-07-01 meeting. From soliver at nrao.edu Mon Jul 12 15:35:53 2004 From: soliver at nrao.edu (Stacy Oliver) Date: Mon, 12 Jul 2004 12:35:53 -0700 Subject: [asac][almanews] ALMA Memo 502 Released Message-ID: <002f01c46847$71bc0250$85dbc5ce@radler> ALMA Memo # 502 ALMA Band 6 Prototype Cartridge: Design and Performance G. A. Ediss, M. Carter*, J. Cheng, J. E. Effland, W. Grammer, N. Horner, Jr., A. R. Kerr, D. Koller, E. F. Lauria, G. Morris, S-K. Pan, G. Reiland and M. Sullivan National Radio Astronomy Observatory *Institut de Radio Astronomique Millimetrique 300 rue de la Piscine 38406 St. Martin d'Heres, France 2004-06-21 Keywords: millimeter-wave receivers, superconductor-insulator-superconductor devices, radio astronomy This paper describes the design and performance of the initial Band 6 (211-275 GHz) ALMA cartridges. The incoming beam is coupled by 4-K reflecting optics to a scalar horn followed by an orthomode transducer. Each polarization is down-converted in a sideband-separating SIS mixer integrated with a pair of 4-12 GHz IF preamplifiers. Stringent thermal management and LO loss requirements are satisfied by using an overmoded stainless-steel waveguide between the LO triplers on the 100-K stage and the 4-K mixers. For ease of maintenance, all connections into the vacuum vessel are "blind mating." View a pdf version of ALMA Memo #502. http://www.alma.nrao.edu/memos/html-memos/alma502/memo502.pdf -------------- next part -------------- A non-text attachment was scrubbed... Name: winmail.dat Type: application/ms-tnef Size: 5016 bytes Desc: not available URL: From soliver at nrao.edu Mon Jul 12 15:34:57 2004 From: soliver at nrao.edu (Stacy Oliver) Date: Mon, 12 Jul 2004 12:34:57 -0700 Subject: [asac][almanews] ALMA Memo 484 Released Message-ID: <002301c46847$50459280$85dbc5ce@radler> ALMA Memo # 484 A New Configuration for the ALMA Laser Synthesizer Bill Shillue and Larry D'Addario National Radio Astronomy Observatory 2004-06-17 Keywords: laser, synthesizer, photonic, local oscillator This memo describes the results of a test of a new configuration of laser synthesizer for ALMA. The ALMA laser synthesizer is the source of the 1st LO photonic reference, in which a two-wavelength optical beatnote is transmitted by optical fiber from the ALMA AOS technical building to each of the array antennas. It is then used at the antenna as the reference for the first local oscillator, after a photomixer converts the beatnote into a radio frequency in the range 27-142 GHz. This report is a condensed version of a more detailed test report available on ALMAEDM. In this new configuration, a slave DFB fiber laser (DFB-FL) is phase-locked to a master laser using an external fiber frequency shifter (FFS). The use of an FFS as an external tuning element removes the requirement for fast modulation response from the slave laser that had heretofore been an obstacle in finding a suitable tunable slave laser. This technique has been implemented previously for very low phase-noise applications. The relatively wide modulation bandwidth allows for a wide bandwidth phase-lock loop. Coupled with the intrinsically low phase noise of the DFB-FL, the resulting beatnote is shown to have very low phase noise. View a pdf version of ALMA Memo #484. http://www.alma.nrao.edu/memos/html-memos/alma484/memo484.pdf -------------- next part -------------- A non-text attachment was scrubbed... Name: winmail.dat Type: application/ms-tnef Size: 5200 bytes Desc: not available URL: From soliver at nrao.edu Mon Jul 12 15:35:31 2004 From: soliver at nrao.edu (Stacy Oliver) Date: Mon, 12 Jul 2004 12:35:31 -0700 Subject: [asac][almanews] ALMA Memo 495 Released Message-ID: <002b01c46847$64f15200$85dbc5ce@radler> ALMA Memo # 495 Estimated Performance of the Water Vapour Radiometers Richard Hills (Cavendish Laboratory, Cambridge, UK) 2004-06-14 Keywords: Phase COrrection, Water Vapour Radiometer The sensitivity and accuracy to be expected from the ALMA water vapour radiometers is estimated. Even with quite pessimistic assumptions about noise temperature and gain stability, it appears that the sensitivity of the present design is at least a factor of 2 better than the specifications. It is more difficult to predict the medium term stability and accuracy that will be achieved, but the indications are that these will not be a limiting factor in using the data from the radiometers. An estimate of the errors that would occur in correcting the single-dish pointing for the effects of water vapour gradients is also given. View a pdf version of ALMA Memo #495. http://www.alma.nrao.edu/memos/html-memos/alma495/memo495.pdf -------------- next part -------------- A non-text attachment was scrubbed... Name: winmail.dat Type: application/ms-tnef Size: 4712 bytes Desc: not available URL: From awootten at nrao.edu Tue Jul 20 14:05:52 2004 From: awootten at nrao.edu (Al Wootten) Date: Tue, 20 Jul 2004 14:05:52 -0400 Subject: [asac]August Telecon Message-ID: <40FD5F00.4050706@nrao.edu> Folks, The Board will hold a telecon on 5 August; the ASAC telecon is scheduled for 3 August. On the Board's agenda is approval of the ASAC charges, which we understand are under active discussion. It has been proposed to shift the ASAC telecon by one week to 10 August in order that discussion can focus on the charges. Let this become the default unless objections are loud. Clear skies, Al From awootten at nrao.edu Tue Jul 20 16:53:01 2004 From: awootten at nrao.edu (Al Wootten) Date: Tue, 20 Jul 2004 16:53:01 -0400 Subject: [asac]ASAC Meeting Charlottesville 27-28 September 2004. Message-ID: <40FD862D.50605@nrao.edu> [Note from Al: Janet had an old list of ASAC members so this may not have reached all current members; I forward her message to this list and apologize to those who will receive it twice. - Al] HI Everyone, This is the first email regarding the next ASAC Meeting being held in Charlottesville, Virginia, USA, the 27th and 28thof September, 2004. The meeting will be held at the NRAO Technical Facility located at 2551 Ivy Road, Charlottesville in the Penthouse Meeting room. Jennifer Neighbours recently relocated from our Tucson office to the NTC. She will be handling this meeting and be your main point of contact. Jennifer can be reached at phone number 434.296.0328 or jneighbo at nrao.edu. Hotel Information A block of rooms has been reserved at the Courtyard by Marriott at the University Medical Center, 1201 W. Main Street, Charlottesville, VA. The room rate is $82.00 per night plus tax. This $82.00 rate is effective from Sunday, 26th September through Saturday, 2nd October. Please email your arrival and departure dates to Jennifer so that she can make your reservations. Upon check-in at the hotel, you will be asked to present your credit card. Rooms must be booked by the 26th of August. Please note that there are no hotel rooms available in the city of Charlottesville on the night of Saturday, 25th September. This is due to the fact the University of Virginia is playing a nationally televised (ESPN) night football game. If you are flying into Washington or Richmond on Saturday, you will need to stay at a hotel near where you land or outside of Charlottesville. Transportation Please provide Jennifer with the following airline information  Arrival date, Airport, Airline, Flight Number and Time of Arrival Preferred mode of transportation from Airport to Hotel Departure date, Airport, Airline, Flight Number and Time of Arrival Preferred mode of transportation from Hotel to Airport Car rentals are available at all of the airports, shuttle service is available from the Charlottesville Airport to the Hotel. Miscellaneous Coffee and lunches will be provided during the meeting. Please let Jennifer know if you have any special dietary needs. Al will be hosting a tour of the NTC. Regards, Janet Janet Bauer NRAO - ALMA North American Project Office 2496 Old Ivy Road, Suite 226 Charlottesville, VA 22903 434.296.0296 (phone) 434.296.0255 (fax) jbauer at nrao.edu (E-mail)