Numbers

  12m Array ACA
Array Altitude
 From 5,000m to 5,100m
Number of Antennas
 50 (up to 64) 12(7m) + 4 (12m)
Total Collecting Area
 5,650 m2 (up to 7,240 m2) 460 + 450 m2
Angular Resolution
 0.02" (λ/1 mm)(10 km/distance) 5.7" (λ/1mm)
Baseline Lengths
 15 - 16,000 m
Antennas Diameter
 12m 7m, 12m
Surface Accuracy
 <25 µm  <20µm, <25µm
Offset Pointing
 <0.6", 2” all-sky absolute pointing under primary operating conditions
Correlator Baselines
 up to 2016 120
Bandwidth
 16 GHz per base line
Spectral Channels
 4096


The 10 Frequency Bands of the ALMA antennas

ALMA Band

Frequency Range
(GHz)

Receiver Noise (K) over 80% of the RF band

Temperature (K) at any RF Frequency

To be produced by 1

Receiver Technology

1

31-45

17

26

tbd

HEMT

2

67-90

30

47

tbd

HEMT

3

84-116

37

60

HIA

SIS

4

125-163

51

82

NAOJ

SIS

5*

163-211

65

105

OSO

SIS

6

211-275

83

136

NRAO

SIS

7

275-373

147

219

IRAM

SIS

8

385-500

196

292

NAOJ

SIS

9

602-720

175

261

NOVA

SIS

10

787-950

230

344

NAOJ

SIS

   

1tbd:    to be decided
IRAM:   Institut de Radio Astronomie Millimétrique (Grenoble, France)
HIA:      Herzberg Institute of Astrophysics (Victoria, Canada)
NAOJ:  National Astronomical Observatory of Japan (Mitaka, Japan)
NOVA:  Nederlandse Onderzoekschool voor Astronomie (Groningen, the Netherlands)
NRAO:  National Radio Astronomy Observatory (Charlottesville, USA)
OSO:    Onsala Space Observatory/Chalmers University (Onsala, Sweden)
* EU FP6 receivers from Onsala