ANASAC Meeting, 25 August 2003 Project Overview and Status Al Wootten, Science IPT Lead

ANASAC Meeting, 25 August 2003

Project Overview and StatusAl Wootten, Science IPT Lead


Main Topics

• Project PlanProject Plan• Negotiations with ChileNegotiations with Chile

• SiteSite• Front ends, antennas, other elements of ALMAFront ends, antennas, other elements of ALMA

• Japanese participationJapanese participation


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)


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


ALMA Management StructureNSF ALMA Board ESO Council

Radio Astronomy PresidentR. Dickman P. van der Kruit

AMAC ASAC

EuropeanAUI Joint ALMA Office ALMA Board

President ALMA Director ChairR. Giacconi P. Vanden Bout (Interim) P. van der Kruit

ALMA Project ManagerM. Tarenghi (Interim)ALMA Project Scientist

North American NRAO S. Guilloteau (Interim) ESO European Executive Director ALMA Project Engineer Director General Executive

F. Lo Vacant C. Cesarsky

North Amercan European Project Manager Project Manager M. Rafal R. Kurz

ALMA Board Members Joint ALMA Safety Europe S. Radford Site Development IPT J. Eschwey Committee P. van der Kruit, Chair M. Boecker, Chair

R. Booth J. Kingsley Antenna IPT S. Stanghellini J. Bolyard, V-Chair

C. Cesarsky R. Wade C. Cunningham Front End IPT G. H. Tan North America R. Dickman, V-Chair C. Janes Back End IPT A. Baudry R. Giacconi J. Hesser J. Webber Correlator IPT A. Baudry A. Sargent

B. Glenndenning Computing IPT G. Raffi

System EngineeringR. Sramek & Integration IPT C. Haupt

A. Wootten Science IPT E. van Dishoeck


ALMA-NA Organization

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


Level-One MilestonesFrom ALMA Agreement

Milestone or Deliverable Date

1. Start Antenna Evaluation at ALMA Test Facility (done Q1 2003) Q4 2002

2. Begin Initial Phase of Civil Works in Chile (done Q3 2003) Q4 2003

3. Central Back End System Ready to Install at Array Site Q1 2005

4. Initial Phase of Civil Works in Chile Complete Q2 2005

5. First Antenna-Based Back End Subsystem Ready for Installation at OSF

Q2 2005

6. First Production Antenna Available in Chile at OSF Q4 2005

7. Initial Front End Subsystem Available at OSF Q4 2005

8. Start Early Science Operations Q3 2007

9. Completion of Construction Project Q4 2011

10. Start Full Science Operations Q1 2012


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


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.

Permissions


• 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


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


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


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


Complete Frequency Access

N.B. Band 1 31.3-45 GHz not shown


Northern ChileSite 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.


Salar de Atacama

0.55, 0.8, 1.6 m Landsat 7, 2000 February 12

Cerro ChajnantorALMA

San Pedro de Atacama

Salar de Atacama

NASA/GSFC


Chajnantor

SW from Cerro Chajnantor, 1994 May AUI/NRAO S. RadfordPhoto: S. Radford


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




Front Ends

Draft ALMA Front End Specifications DocumentTable 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-ZZZ2 28 K 43 K 14 K 22 K FEND-22910-ZZZ3 34 K 54 K 17 K 27 K FEND-23910-ZZZ4 47 K 76 K 24 K 38 K FEND-24910-ZZZ5 60 K 98 K 30 K 49 K FEND-25910-ZZZ6 77 K 126 K 39 K 63 K FEND-26910-ZZZ7 133 K 198 K 67 K 99 K FEND-27910-ZZZ8 181 K 270 K 91 K 135 K FEND-28910-ZZZ9 335 K 500 K 168 K 250 K FEND-29910-ZZZ10 438 K 655 K 219 K 328 K FEND-20910-ZZZ


Preliminary Cartridge Design

• Optics• Two mixers• IF amplifiers• Local oscillator• Cables• Mount


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


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.


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


Antennas


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.


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

Documents

ANASAC Meeting, 25 August 2003 Project Overview and Status Al Wootten, Science IPT Lead