HERA

HERA construction is in full throttle again after a short slow down to prepare for the larger scale construction of the fully funded project. In this period, the focus had been on preparing the infrastructure, hiring the people and buying the material.

The overall focus of the project has been to address the software development to handle the data. A comprehensive set of Teams have been set up and the project follows a “best practice” philosophy of development and coding.

Staffing

HERA now enjoys three critical full-time staff in Cape Town who are responsible for the entire delivery of the array infrastructure and antennas. Kathryn Rosie serves as the Project Engineer and has been spearheading these efforts; Ziyaad Halday serves as the SA Project Manager; and Yanga Balfour as the Project Controller, primarily focusing on logistics. Additionally, nine full-time employees in the Karoo are doing the actual installation work, with an additional five positions to be filled soon. Samantha Pieterse, Lourence Malan, Austin Julius, Randall Fritz and Cresshim Malgas have been working with HERA for two years and are now joined by Rushelle Baartman, Hans Nuwegeld, Jerome Sacco and Jerrian Harris.

Infrastructure

In its previous configuration, the container housing the correlator for PAPER and early HERA sat in the middle of a 300m cleared circle alongside another container that served as the construction office. HERA will completely fill this cleared circle, so the containers had to be relocated to the edge of the cleared area, some 200m to the West. Additionally, the new architecture makes use of “nodes” interspersed with the antennas, which provide a housing for the digitisers/channelizers. Each node can accommodate up to 12 antennas, and power and fibre will be provided via underground reticulation. July saw the containers and associated utilities relocated, with an extra container unit added to provide additional working space. Construction of 37 elements is now complete, with substantial components for the first 100 elements in place.

Figure: Image showing the 37 constructed HERA dishes, with some of the installed poles for the next 73 elements (credit David DeBoer).

As mentioned in the last Newsletter, HERA is undergoing a phased architecture change. The 2017/2018 observing season still reuses the PAPER signal path concept in its entirety, albeit in a new configuration, however new versions of the front-end and post-amplifier developed and built at Cambridge University will be used. In addition to replacing the aging PAPER signal paths (some of which operated continuously for over 5 years!) this allows much of the new analog hardware to be tested before the full system is deployed in mid-2018.

Also under field-test this year, are the new node enclosures with a subset of the hardware in them, including the new Smart Networked ADC Processors (SNAP), developed for HERA and now part of the broader CASPER suite of boards. Another SNAP has been deployed with the existing correlator to test in parallel with the current, well-characterised correlator.

Another key infrastructure move, has been to move the post-processing cluster from a temporary shielded container to its intended location in the shielded room within the Karoo Array Processor Building. This move completes the infrastructure shift and allows us to test full network connectivity.

Figure: CHAMP Camp participants, held at Cal Poly Pomona June 2017 (Credit Cal Poly Pomona).

This summer we are very proud of the participation of students in our CAMPARE-HERA Astronomy Minority Partnership (CHAMP) programme. In June, our first “CHAMP Camp” was held at Cal Poly Pomona to kick off the summer. This camp brought together 12 students from California State Universities, California community colleges, and South Africa to learn about radio astronomy and key research skills from HERA scientists. The students are currently participating in a 9-week research programme at various HERA institutions, including UC Berkeley, the University of Washington, MIT, and the University of Pennsylvania. Research projects range from the design and testing of electronics to simulations and data analysis. The programme concludes at the end of August when students will present their projects in the 5th Annual Cal-Bridge/CAMPARE/CHAMP Research Symposium at Cal Poly Pomona.

HERA is a partnership to conduct an experiment to detect and characterise the Epoch of Reionization. Partner institutions in the collaboration are Arizona State University, Brown University, University of California Berkeley, University of California Los Angeles, University of Cambridge, Massachusetts Institute of Technology, National Radio Astronomy Observatory, University of Pennsylvania, Scuola Normale Superiore de Pisa, SKA-South Africa and the University of Washington. Additional collaborators are Cal Poly Pomona, Imperial College, Harvard-Smithsonian Center for Astrophysics, University of KwaZulu Natal, Rhodes University and University of Western Cape.


Report provided by David de boer, University of Berkeley, HERA Project Manager