ALMA Science Advisory Committee

Teleconference, 3 April 2002

Draft Minutes

Participants: R. Booth, L. Bronfman, P. Cox, R. Crutcher, N. Evans, M. Gurwell, T. Hasegawa, J. Mangum, D. Mardones, H. Matsuo, L. Mundy, J. Richer, P. Schilke, K. Tatematsu, E. Van Dishoeck, M. Walmsley, D. Wilner, C. Wilson, A. Wootten, S. Yamamoto, M. Yun

The proposed agenda was adopted, and the minutes of the previous telecon were accepted.

(1) Discussion of the first point was deferred as an appropriate presenter was not present.

(2) The second point on the agenda was a discussion on the face-to-face meeting draft report to the ACC. P. Cox noted the tight schedule, with the executive summary to be sent by Friday 5 April to the ACC, and the complete report to follow on Monday 8 April. Cox summarized several points from an ESAC telecon held on 2 April: the PRC section will be shortened, with the lengthy discussion placed in an Appendix, to be accomplished by Cox. Recommendations of the ASAC will be highlighted, as in the September report, also to be accomplished by Cox. Further, discussions on the three way project, including Japan, will be summarized for a new section.

The Chair called for questions, particularly from non-attendees. Chris Wilson asked for a definition of a commissioning receiver. Van Dishoeck gave the three model receiver philosophy presented at the meeting by Wild: (1) Engineering model (underway, no serial number); (2) Qualification model (serial number 000) subject to a pre-production review, and (3) Production model (serial numbers 1-64) for use on ALMA. A four band cryostat is scheduled to be in place on ALMA by Q4 2007 in a plan presented at Mitaka. Wilson further asked for clarification on the AIPS++ report. The final report is due by month's end and is was decided to await that. Richer noted that the report at the meeting was more positive than the report draft might currently reflect. Discussion ensued on the overlap of the e2e (end-to-end) program at NRAO with ALMA studies. It was noted that some items within the e2e framework have been assigned, for instance to Europe and ALMA implementation may diverge from the NRAO e2e plan. Wilson suggested that in some particulars, ALMA discussions may lead e2e discussions and those members on NRAO committees should consider the interplay of ideas as the two parallel programs reach their final form. Wilson asked about OSF locations; at the face-to-
face meeting one option near Toconao had been described but no decision has been taken. Mundy asked how many RSCs were foreseen, to which Cox replied that one per partner had been discussed, organized in a partner-dependent fashion. Mundy suggested that proximity to a major airport might be a consideration. Gurwell asked for an evaluation of the antenna risk. Wootten replied that the Vertex antenna appeared to be on schedule for a 29 July acceptance but that the other antennas were not far enough along for a meaningful assessment. The 40 week ATF testing routine however suggested delivery should not slip beyond April for the 1 Jan 2004 deadline for reports to be met. Gurwell suggested that the receiver stability section be amplified. Van Dishoeck noted that we do not yet know what can be achieved. Wootten offered to add references to previous ASAC documents on this subject, and to make sure that it is covered in the Project Book. Wilner asked about the largest configurations. Wootten replied that a new concept, utilizing the OSF road, was being studied as an alternative to the Chascon Ring concept. One scientific ramification is that the OSF-road concept, with a more Y-like configuration, would offer better hybrids than a ring, but somewhat less maximum resolution than the ring. A study is underway with a memo expected reasonably soon. Gurwell inquired about the definition of stringency, referred to in the report. Perhaps the concept is too abstract and should be replaced by specific words. Consensus was that stringency required some thought but was the proper word for inclusion. Hasegawa noted that there was some imbalance in the treatment of proposal overlap between partner-based and subject based PRCs. Treatment of proposals for overlapping science should be defined in a parallel way for the two models. Schilke and Cox will work on this.

(3) Wootten will poll the ASAC on dates for the next face-to-face meeting, planned for Socorro at some point during the weeks of 9 or 16 September 2002.

(4)Finally the next teleconference is planned for May 2 at 13:000 UT.