The Submillimeter Array

Receiver Lab Talks: 2023

Questions: Edward Tong
Time: Wednesday 1:00 PM EST/EDT
Where: Zoom

Date Speaker Title Summary
Feb 1Edward Tong
Test Data from the first wSMA Receiver The prototype wSMA cryostat has recently been shipped to Mauna Kea, Hawaii, and one round of optical alignment has been performed. The low and high band wSMA cartridges, together with their associated LO modules will be shipped in February, with the hope that they will see first light shortly thereafter. In this talk, I will present the perfromance data collected on this receiver pair in the Receiver Lab in Cambridge, during the integration tests, as well as the projected schedule for wSMA receiver deployment.
Feb 8Kieran Cleary
The CO Mapping Array Project (COMAP) The CO Mapping Array Project is using its Pathfinder instrument to perform line intensity mapping of galaxies at z~3. The Pathfinder is a 19-feed single-polarization spectrometer focal plane array fielded on a 10.4-m telescope at the Owens Valley Radio Observatory. In this talk, I will report on the Pathfinder instrument design, the current status of the Pathfinder Survey and future plans for the project involving a prototype dish for the next generation Very Large Array.
Feb 15Paul Grimes
Verifying Optical Alignment of the wSMA Receivers As part of the instrument verification process before the deployment of the first prototype wSMA receiver, we have carried out a series of alignment measurements, firstly using visible light, and then with millimeter-wave coherent beam scanning. I will discuss our set up for measuring and adjusting the optical alignment of the wSMA Receiver system, and the millimeter-wave beam scanning technique that we have used in the lab. I will present results from beam scanning experiments in Cambridge Receiver Lab, and discuss plans for how we will verify the millimeter-wave beam alignment when the wSMA receiver is installed in an SMA antenna.
Feb 22Miranda Eiben
Harvard University
Development of Large Thin Windows for Millimeter Receivers As aperture sizes grow, the vacuum windows of millimeter receivers must balance the competing needs of strength and transparency. We have developed a new strategy to generate highly transmissive and strong windows by laminating woven High Modules Polyethylene (HMPE) with Low Density Polyethylene (LDPE), resulting in windows approximately half a wavelength thick (0.7 to 2 mm). Such laminate windows have been tested extensively, and are currently deployed on both BICEP3 and the newest BICEP Array receiver at the South Pole.
March 1Elliot Richards
8 GHz Block Downconverter Design for the Next Generatiobn Event Horizon Telescope (ngEHT) The Next Generation Event Horizon Telescope (ngEHT) will doubke the current EHT bandwidth, digitizing 8 GHz, per polarization, per sideband. This talk will detail the design of a novel instrument capable of downconverting this wide bandwidth in a single block and conditioning the analog signal for optimal digitization. We will share results from our prototype testing and plans for manufacturing the final device.
March 8Edward Tong
wSMA High Band Local Oscillator The wSMA High Band Local Oscillator is specified to drive the dual polarized wSMA High Band receivers between 280 and 360 GHz. In this talk, I will present the architecture and implementation, as well as some measured data from the first module.
April 19Jake Connors
Re-defining G in transition edge sensor bolometer design: Applications to Far-Infrared Spectroscopy High resolution direct-detection spectrometers, operating from 30-300um with spectral resolution of up to R~10^5, require broadband, direct absorption detectors with noise equivatlent powers (NEP) of < 10^-19 W/rt-Hz to perform background limited observations. Transition edge sensor (TES) detectors are broadband, and they have a simple electrothermal response as well as well understood fabrication. In addition to operating them at increasingly low temperatures, these NEP's can be achieved through the reduction of the bolometers' thermal link to the bath, G. Instead of fabricating very narrow or long TES thermal links, we choose to utilize coherent phonon transport effects to systematically reduce G. Presented herein is a study of various TES thermal link designs approaching extreme dimensions, exploring fabrication feasibility, theoretical calculations of detector performances, and discussion of upcoming measurements of fabricated TES detectors.
April 26Bert Hawkins
Joey Lambert
NRAO's Central Development Lab and the ALMA Band 6 Receiver Upgrade Bert Hawkins will provide an overview of NRAO's Central Development Laboratory, covering the major projects and initiatives the lab is currently working on, including on-going work for ALMA and ngVLA in receivers, low noise amplifiers, optics/electromagnetics, DSP/correlator, and timing distribution. He will also cover some new areas for CDL such as LNA technology development, radar development using the Green Bank telescope, spectrum monitoring hardware to support NSF"s National Radio Dynamic Zone initiative. He will also briefly cover new programs at CDL to recruit and develop future engineers and researchers at CDL.
Joey Lambert will focus specifically on ALMA Band 6 receiver upgrade project, including updates on the development of a new Band 6 mixer and other key components.
May 3Matthew Petroff
Applications of 3D Printing for Millimeter-wave Instrumentation Additive manufacturing in the form of 3D printing has become increasingly widespread in recent years. As this technology can produce submillimeter-sized features, it has potential uses in instrumentation and optics for millimeter wave astronomy, such as in cosmic microwave background experiments. This talk will discuss the application of such technology to the development of a broadband millimeter-wave absorber printable via the extrusion of a carbon-loaded thermoplastic. It will then move on to discuss the use of sterolithography-based 3D printing, with a focus on the fabrication of copper-plated Q-band waveguide components.

Previous presentations available here: CfA managed Google Drive