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Project Overview and Status Al Wootten, Science IPT Lead

This document provides an overview of the ALMA project plan, negotiations with Chile, site selection, and the status of front ends, antennas, and other project elements. It also discusses Japanese participation and the ALMA management structure.

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Project Overview and Status Al Wootten, Science IPT Lead

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  1. Project Overview and StatusAl Wootten, Science IPT Lead ANASAC Meeting, 25 August 2003

  2. Main Topics • Project Plan • Negotiations with Chile • Site • Front ends, antennas, other elements of ALMA • Japanese participation ANASAC Meeting, 25 August 2003

  3. ALMA Project Plan • defines top-level requirements, specifications, and scope of the (baseline) project • gives a top-level description of the project implementation, including operations • defines project organization • presents top-level project budget • presents top-level project schedule and milestones • is consistent with the Bi-lateral ALMA Agreement and is an ALMA Board-approved document (Version 1) ANASAC Meeting, 25 August 2003

  4. ALMA Management Structure • Joint ALMA Office (JAO) established in June 2002 with interim key personnel • Provides single, central decision-making authority • M. Tarenghi appointed ALMA Director, effective April 2003 • Remaining permanent key personnel will be appointed as rapidly as possible • Nominations sought by Search Committee, especially for Project Scientist • Contact Anneila Sargent ANASAC Meeting, 25 August 2003

  5. ALMA Management Structure ANASAC Meeting, 25 August 2003

  6. ALMA-NA Organization ANASAC Meeting, 25 August 2003

  7. Milestones • Level 1 Milestones • Top-level milestones for the Project • Specified by the ALMA Board • Define the overall schedule for the Project. • Level 2 Milestones • Derived from the Level 1 Milestones • Define the framework for the work of each IPT and the interaction amongst IPT’s when key deliverables are involved. • Controlled by JAO • Level 3 Milestones • Derived from the Level 2 milestones • Define the schedule for the work within each IPT • Defined to be fully consistent with the overall schedule of the Project • Controlled by IPT and reported to JAO

  8. Level-One MilestonesFrom ALMA Agreement ANASAC Meeting, 25 August 2003

  9. Negotiations with Chile • Top – Level Requirements • permissions for AUI and ESO to build/operate ALMA • long-term (50-year) access to the ALMA site • sale of land to ESO and AUI for an operations base at 2800m elevation – the Operations Support Facility • an approved Environmental Impact Statement ANASAC Meeting, 25 August 2003

  10. Permissions AUI has the right to build and operate ALMA under the terms of an MOA with the University of Chile, which, through Law 15.172, gives AUI the same immunities and privileges as ESO Permission for ESO to open a new observing site has been negotiated with the Chilean Government and approved by Foreign Affairs, Parliament and the President. ANASAC Meeting, 25 August 2003

  11. Land • Bienes Nationales has made a concession of the site through a contract to a Chilean corporation, Radioastronomia Chajnantor, formed and held jointly by ESO and AUI • contract calls for annual rent payments • concession includes the land for an access road from the OSF to the high site • Construction began 2003 July 26 ANASAC Meeting, 25 August 2003

  12. Land (cont’d) • OSF land (100 hectares) sold to AUI/ESO and a right-of-way granted for an access road from Highway 23 to the OSF • concession contract takes effect on execution of agreements between AUI/ESO and CONICYT, for the development of astronomy in Chile, and Region 2, for the support of cultural activities ANASAC Meeting, 25 August 2003

  13. Environmental Impact Statement (EIS) • The EIS was filed on July 1, 2002, and is limited to a maximum of 120 working days (20 weeks) plus time required to respond to questions • We require access to the site by April 1, 2003 • Two addenda to the EIS were filed, answering questions and issues raised by 13 government agencies involved in process, with positive reaction from all • The EIS was approved 13 March 2003 by the Regional Environmental Council, without (additional) restrictions or conditions ANASAC Meeting, 25 August 2003

  14. Front End Specifications • Frequencies from 31 to 950 GHz covered in 10 bands • requires RF bandwidth up to 30% • All bands dual polarization • 8 bands use SIS mixers at 4K • Mixers separate sidebands where possible • Highest possible sensitivity and stability • receiver noise close to quantum limit • wide detection bandwith (IF 4-12 GHz) • Highest reliability (1280 systems) • Modular design • Four bands to be built during ALMA Construction ANASAC Meeting, 25 August 2003

  15. Complete Frequency Access N.B. Band 1 31.3-45 GHz not shown ANASAC Meeting, 25 August 2003

  16. Northern Chile Site must be high to make the best use of the atmospheric windows. Site should also be accessible, supported by reasonably close support facilities. Site should be dry for transparency. Chajnantor lies relatively close to the ancient town of San Pedro de Atacama, inhabited for more than two millennia. San Pedro is relatively near the Calama airport, and not far from the ESO site at Paranal. Chajnantor lies astride the paved Pasa de Jama road to Argentina; major gas pipelines from Argentina traverse it. ANASAC Meeting, 25 August 2003

  17. Salar de Atacama San Pedro de Atacama Cerro Chajnantor ALMA Salar de Atacama 0.55, 0.8, 1.6 mm Landsat 7, 2000 February 12 ANASAC Meeting, 25 August 2003 NASA/GSFC

  18. Chajnantor SW from Cerro Chajnantor, 1994 May Photo: S. Radford AUI/NRAO S. Radford ANASAC Meeting, 25 August 2003

  19. Chajnantor Evaluation • Clarity of atmosphere: superior to Mauna Kea; at best better than South Pole • Source accessibility: superior to South Pole • Site monitoring continues 1994-present, by NRAO, ESO and NAOJ • Comparison with first years of Caltech CBI operations • Evaluation • Transparency monitoring extended to supraTHz windows • Radiosonde campaign extended to cover all seasons • Installation and upgrade of monitoring equipment, communications • Array center site chosen • Site construction activities commence 2003 ANASAC Meeting, 25 August 2003

  20. ANASAC Meeting, 25 August 2003

  21. ANASAC Meeting, 25 August 2003

  22. ANASAC Meeting, 25 August 2003

  23. Front Ends Draft ALMA Front End Specifications Document Table 2: Specifications for maximum receiver noise temperatures Band SSB DSB T(SSB) T(SSB) T(DSB) T(DSB) Spec ref. 80% any  80% any  1 15 K 23 K 8 K 12 K FEND-21910-ZZZ 2 28 K 43 K 14 K 22 K FEND-22910-ZZZ 3 34 K 54 K 17 K 27 K FEND-23910-ZZZ 4 47 K 76 K 24 K 38 K FEND-24910-ZZZ 5 60 K 98 K 30 K 49 K FEND-25910-ZZZ 6 77 K 126 K 39 K 63 K FEND-26910-ZZZ 7 133 K 198 K 67 K 99 K FEND-27910-ZZZ 8 181 K 270 K 91 K 135 K FEND-28910-ZZZ 9 335 K 500 K 168 K 250 K FEND-29910-ZZZ 10 438 K 655 K 219 K 328 K FEND-20910-ZZZ

  24. Preliminary Cartridge Design • Optics • Two mixers • IF amplifiers • Local oscillator • Cables • Mount ANASAC Meeting, 25 August 2003

  25. Front End Concept • Ten bands, one 1 m diameter dewar with 70K, 15K and 4K stages • Each band a modular ‘cartridge’ held by flexible thermal links • All bands share focal plane, cartridges plug in from bottom, optics atop ANASAC Meeting, 25 August 2003

  26. CryostatRAL—Delivery end of 2003 Engineering model Cryostat fitted with quartz and HDPE based windows. Fitted with dummy receiver loads, met cooldown and hold test goals. ANASAC Meeting, 25 August 2003

  27. The ALMA AntennaMechanical Engineering at the Heart of the Array • Must maintain accuracy at 16,500 foot Llano de Chajnantor • Surface accuracy better than 20 microns • Pointing accuracy better than 0.6 arcseconds • Despite • high winds (50 percentile 6.5 m/s) • no vegetation - windblown grit and dust • annual median temperature -2.5 C (range -20 to +20 C) • pressure 55% of sea level--UV radiation (170% of sea level) • Three designs, first two of which are ALMA prototypes • ALMA/NA VertexRSI, of Santa Clara, CA much carbon fiber of a novel sort • ALMA/EU Alcatel Space, France, and EIE, of Venice with Castamasagna , Italy, using considerable carbon fiber • Japanese refinement of ASTE pre-prototype built by Mitsubishi, Japan • Final design after 1.5yrs of tests in New Mexico ANASAC Meeting, 25 August 2003

  28. Antennas ANASAC Meeting, 25 August 2003

  29. Japanese Participation in ALMA • The NAOJ will propose to MEXT that Japan join ALMA starting 1 April 2004 (on a < 1/3 basis). • The NAOJ has proposed to the ALMA Board that they become partners in ALMA, bringing a set of enhancements to the baseline project. • The ALMA Board has appointed a Japan Negotiating Team to negotiate the terms of the partnership. • The JAO is supporting the Japan Negotiating Team with a technical and cost evaluation of the Japanese proposal. • The matter should be settled in calendar 2003. ANASAC Meeting, 25 August 2003

  30. Enhancements being discussed • ALMA Compact Array = (12) 7m + (4) 12m antennas in a closely packed configuration to provide sensitivity to diffuse sources and enhanced submm capability • Additional receiver bands = Band 4 (125-163 GHz ), Band 8 (385-500 GHz ), and Band 10 (787-950 GHz ) • ACA correlator • Additional Japanese contributions • Incremental costs to baseline project that are a consequence of implementing the program of enhancements and of their participation in ALMA • Proportional share of operations costs ANASAC Meeting, 25 August 2003

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