The ALMA Band-7 Cartridge

Mahieu, S.; Maier, D.; Lazareff, B.; Navarrini, A.; Celestin, G.; Chalain, J.; Geoffroy, Denis; Laslaz, F.; Perrin, Greg

doi:10.1109/tthz.2011.2177734

Cited by 27 publications

(10 citation statements)

References 1 publication

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“…The sideband-separating mixer employed in Band 4 has been originally developed for the ALMA Band 7 cartridge (Maier et al 2005a) and tuned down in frequency to match the EMIR Band 3 frequency range. Since the ALMA mixer had to be produced in a small series production, emphasis had been laid on an easy and reliable fabrication.…”

Section: Bandmentioning

confidence: 99%

The EMIR multi-band mm-wave receiver for the IRAM 30-m telescope

Carter

Lazareff

Maier

et al. 2012

A&A

198

160

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Aims. The prime motivation of this project was to design and build a state-of-art mm-wave heterodyne receiver system to enhance the observing throughput of the IRAM 30-m radiotelescope. More specifically, the requirements were i) state-of-art noise performance for spectroscopic observations; ii) simultaneous dual polarization and dual-frequency observing; iii) coverage of the atmospheric transmission windows from 83 to 360 GHz; iv) compact footprint and minimal maintenance. Methods. Key elements for low noise performance of heterodyne mixers are the superconducting Niobium junctions, operating at 4 K. These junctions are embedded in carefully designed coupling structures; furthermore, since atmospheric radiation is a significant contributor to the system noise budget, all mixers are either sideband separating or sideband rejecting. To achieve low noise, it is also essential to maximize the coupling of the receiver to the astronomical source, and to minimize the coupling to thermal radiation from the ground-based environment; this is achieved through mirror optics that realize a wavelength-independent coupling to the telescope. A flexible configuration of mirrors and frequency selective surfaces permits various combinations of frequency bands, as well as dual-load radiometric calibration. Low noise intermediate frequency amplifiers and bias electronics also play an important role in the system performance. Results. The EMIR receiver in operation at the 30 m telescope offers four frequency bands: B1: 83−117 GHz, B2: 129−174 GHz, B3: 200−267 GHz, and B4: 260−360 GHz. In each band, the two orthogonal polarizations are observed simultaneously. Dual-band combinations B1/2 B1/3, and B2/4 are available. Bands 1 and 4 (also 3 as of Nov.-2011) feature sideband separation. In dual-band configuration, including sideband separation and polarization diplexing, up to eight IF channels are delivered to the spectrometers, totaling up to 64 GHz of signal bandwidth (of which 32 GHz can be transported and processed by spectrometers, status Nov.-2011). The EMIR receiver has been in continuous operation for more than two years and has allowed, through a qualitative jump in performance, observations not possible before, as shown by a few selected examples of astronomical results.

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Section: Bandmentioning

confidence: 99%

The EMIR multi-band mm-wave receiver for the IRAM 30-m telescope

Carter

Lazareff

Maier

et al. 2012

A&A

198

160

View full text Add to dashboard Cite

show abstract

“…Using the APEX telescope, we observed the o-H 2 D + at 372.421 GHz toward TW Hya during 3.8 h on source in July and September 2010 with the new FLASH 345 receiver. The dualpolarization receiver FLASH operates a two-SB SIS mixer provided by IRAM (Maier et al 2005). The July and September observations were carried out with different backends, respectively leading to spectral resolutions of 0.15 km s −1 and 0.06 km s −1 .…”

Section: Observationsmentioning

confidence: 99%

A deep search for H₂D⁺in protoplanetary disks

Chapillon

Parise

Guilloteau

et al. 2011

A&A

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Context. The structure in density and temperature of protoplanetary disks surrounding low-mass stars is not well known yet. The protoplanetary disks' midplane are expected to be very cold and thus depleted in molecules in gas phase, especially CO. Recent observations of molecules at very low apparent temperatures (∼6 K) challenge this current picture of the protoplanetary disk structures. Aims. We aim at constraining the physical conditions and, in particular, the gas-phase CO abundance in the midplane of protoplanetary disks. Methods. The light molecule H 2 D+ is a tracer of cold and CO-depleted environment. It is therefore a good candidate for exploring the disks midplanes. We performed a deep search for H 2 D + in the two well-known disks surrounding TW Hya and DM Tau using the APEX and JCMT telescopes. The analysis of the observations was done with DISKFIT, a radiative transfer code dedicated to disks. In addition, we used a chemical model describing deuterium chemistry to infer the implications of our observations on the level of CO depletion and on the ionization rate in the disk midplane. Results. The ortho-H 2 D+ (1 1,0 −1 1,1 ) line at 372 GHz was not detected. Although our limit is three times better than previous observations, comparison with the chemical modeling indicates that it is still insufficient for putting useful constraints on the CO abundance in the disk midplane. Conclusions. Even with ALMA, the detection of H 2 D + may not be straightforward, and H 2 D + may not be sensitive enough to trace the protoplanetary disks midplane.

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“…Sideband separating designs [8,9] use two mixers combined to provide two separate output ports for the upper and lower signal sideband. This makes it easier to disentangle emission from the two sidebands in a crowded spectrum and also avoids noise contamination by atmospheric absorption features in the image sideband of the observed signal.…”

Section: Detectorsmentioning

confidence: 99%

“…This can be achieved in the spectral domain by increasing the instantaneous bandwidth of the [5] receivers using SIS mixers (grey) [6][7][8][9][10][11][12] and by GREAT [13,14] using HEBs (black). The straight lines indicate the quantum limit hν/k B and multiples of it arrays for terahertz frequencies, and an increasing number of arrays with on the order of 100 pixels in the submillimeter.…”

mentioning

confidence: 99%

Terahertz Heterodyne Array Receivers for Astronomy

Graf

Honingh

Jacobs

et al. 2015

J Infrared Milli Terahz Waves

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We review the development of multi-pixel heterodyne receivers for astronomical research in the submillimeter and terahertz spectral domains. We shortly address the historical development, highlighting a few pioneering instruments. A discussion of the design concepts is followed by a presentation of the technologies employed in the various receiver subsystems and of the approaches taken to optimize these for current and future instruments.

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The ALMA Band-7 Cartridge

Cited by 27 publications

References 1 publication

The EMIR multi-band mm-wave receiver for the IRAM 30-m telescope

The EMIR multi-band mm-wave receiver for the IRAM 30-m telescope

A deep search for H₂D⁺in protoplanetary disks

Terahertz Heterodyne Array Receivers for Astronomy

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The ALMA Band-7 Cartridge

Cited by 27 publications

References 1 publication

The EMIR multi-band mm-wave receiver for the IRAM 30-m telescope

The EMIR multi-band mm-wave receiver for the IRAM 30-m telescope

A deep search for H2D+in protoplanetary disks

Terahertz Heterodyne Array Receivers for Astronomy

Contact Info

Product

Resources

About

A deep search for H₂D⁺in protoplanetary disks