Instrumentation for radio astronomy (HERA and SKA)
Lead Research Organisation:
University of Cambridge
Department Name: Physics
Abstract
In this project the student will research innovative ways to design more sensitive, better, front ends for the HERA and SKA telescopes.
People |
ORCID iD |
| Eloy De Lera Acedo (Primary Supervisor) | |
| Nicolas Fagnoni (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| ST/N50399X/1 | 01/10/2015 | 31/03/2021 | |||
| 1641316 | Studentship | ST/N50399X/1 | 01/10/2015 | 30/09/2018 | Nicolas Fagnoni |
| Description | I developed a new Vivaldi feed for the Hydrogen Epoch of Reionization Array (HERA), a new radio-telescope dedicated to the study of the early universe. After a long design process performed with electromagnetic simulation software, and validated with measurements, this feed had been chosen to upgrade the telescope. This feed is 1.8-m large and 1.6-m high, weights about 50 kg, and illuminates a 14-m diameter parabolic reflector. 350 elements are currently being deployed in the Karoo desert in South Africa. This new feed is replacing the old one, and has the advantage of working over a larger bandwidth, being more sensitive, and more stable in terms of frequency response. Thanks to these improvements, it will be possible to better study the fluctuations in the quantity of neutral hydrogen present in the intergalactic medium during the early universe over a longer period of time. The ultimate goal of this telescope is to use these fluctuations as a probe to study the formation of the first stars and galaxies. Moreover, I also studied in detail the different types of systematic effects which can distort the received signal, for instance the reflections between the feed and the dish, the interactions between the antenna and the electronics, the reflections in the cables, and the coupling between the adjacent antennas of the array. I combined all these elements together in a single global simulation of the array in order to characterise the frequency and time response of the system. It is crucial to understand and minimise these effects in order to properly calibrate the telescope. |
| Exploitation Route | This feed opens new opportunities to study the early Universe (Cosmic Dawn and Epoch of Reionization). Once the deployment is completed, the telescope will collect new data for half a year which will be then analysed by the members of the HERA team. The challenge is to separate the intense background signal from the hydrogen signal emitted about 13 billion years ago. If it can be successfully done, it will be possible to confirm or update the astrophysical models describing the formation and evolution of our universe. In addition, the simulations that I developed to characterise the response of the system will be used to calibrate the data produced by the telescope. |
| Sectors | Digital/Communication/Information Technologies (including Software),Electronics,Other |
| URL | https://reionization.org/ |
| Description | Isaac Newton Studentship |
| Amount | £42,000 (GBP) |
| Organisation | University of Cambridge |
| Sector | Academic/University |
| Country | United Kingdom |
| Start | 10/2015 |
| End | 09/2018 |
| Description | Mechanical design and construction of prototypes of a new Vivaldi feed for HERA |
| Organisation | Cambridge Consultants |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | -Design of a new Vivaldi feed for HERA -Validation of the modifications of the initial design induced by the constraints of the mechanical design |
| Collaborator Contribution | -Transform the initial electromagnetic design into a real mechanical design which can be actually built; this includes for example the choice of the materials, position of the different bolts and nuts, design of a structure to support the feed, wind load and weight reduction... -Organise the manufacturing of the first prototypes. |
| Impact | -Construction of prototypes -Multi-disciplinary collaboration: electromagnetic antenna design and simulations (OUR contribution), and mechanical engineering (THEIR contribution) |
| Start Year | 2017 |
| Title | Design and development of a new wideband Vivaldi feed for HERA |
| Description | I developed a new wideband Vivaldi feed for HERA. This new receiver will replace the current dipole and will be suspended over a 14-m diameter dish. In its final configuration, HERA will comprise 350 elements. This new feed was specifically adjusted in order to match the front end module of the analogue chain. |
| Type Of Technology | Systems, Materials & Instrumental Engineering |
| Year Produced | 2018 |
| Impact | Compared with the current dipole feed which is a resonant antenna, the Vivaldi feed is a "traveling wave antenna". This type of antenna has the inherent property to have stable characteristics (beam, impedance, reflection coefficient...) over a wide bandwidth. Thus, the bandwidth of the antenna will be extended from 100 - 200 MHz to 50 - 250 MHz thanks to this new feed. Probing lower frequencies means that HERA will be able to study the "Cosmic Dawn" and the formation of the first stars and galaxies of our universe. Moreover, by probing higher frequencies HERA should be able to study the end of the Epoch of Reionization, period during which the intergalactic medium was ionized by the first galaxies. This will allow us to study the formation and evolution of the first structure of our universe. Moreover, the feed was designed to be more sensitive and have a smoother response, in other words less systematics, which is crucial to separate the EoR signal which is 10^5 less intense from the galactic foreground signal. |
| Description | Alumni festival of the University of Cambridge |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Public/other audiences |
| Results and Impact | During the Alumini Festival organised by the University of Cambridge, I spent half a day presenting some recent works performed by the Astrophysics group. In particular, I brought some antenna prototypes developed for the SKA and HERA.The goal was to attract the public, discuss with the alumini about radio-astronomy and the involvement of the University in the development of the SKA and HERA, and answer their question in an informal way. |
| Year(s) Of Engagement Activity | 2017 |
| URL | https://www.alumni.cam.ac.uk/events/alumni-festival-2017 |
| Description | Graduate conference (Cambridge) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Postgraduate students |
| Results and Impact | During the annual graduate conference organised by the Physics department of the University of Cambridge, I gave a 20-min presentation about my research. In particular, I presented purpose and characteristic of HERA, explained how I can model and simulate the electromagnetic and electrical properties of the HERA antenna and the RF analogue chain, along with the systematics which affect the received signal. Lastly, I answered the questions of the audience. |
| Year(s) Of Engagement Activity | 2016 |
| Description | Physics at Work (Cambridge) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Schools |
| Results and Impact | Physics at Work was a 3-day event organised by the University of Cambridge during which mainly PhD students from the Physics department presented their research field to young pupils aged between 14 - 16. The goal was to promote Physics, show the diversity of the different disciplines, and encourage the pupils to consider a career in Science. I was personally involved for 1 day. Concerning its format, each half a day we received 6 classes of about 15 pupils. With each class, I spent about 25 minutes during which I gave a personal presentation of radio-astronomy as well as a brief overview of our research, trying to arouse their interest and answering their questions. In particular I chose to talk about the SKA as an example of next-generation radio-telescope. |
| Year(s) Of Engagement Activity | 2017 |
| URL | https://outreach.phy.cam.ac.uk/programme/physicsatwork |
| Description | Talk about radio-astronomy to international undergradute students (Cambridge) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Undergraduate students |
| Results and Impact | I gave a 20-min talk about radio-astronomy to a large group (~30) of undergraduate students coming from Belgium to visit the University of Cambridge. In particular, I gave an overview of my research on the development of HERA and the SKA. I also spent about 10 minutes answering their questions, mainly related to these telescopes. |
| Year(s) Of Engagement Activity | 2016 |
| Description | Talk during IGM 2018: Revealing Cosmology and Reionization History with the Intergalactic Medium |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | -Talk about the development of a new Vivaldi feed for HERA and its impact on the detection of the EoR signal -Audience: ~ 80 people -Outcomes: technical questions |
| Year(s) Of Engagement Activity | 2018 |
| URL | https://indico.ipmu.jp/indico/event/156/ |
| Description | Talk during a cosmology conference (South Africa) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Study participants or study members |
| Results and Impact | 20-min presentation about my research. In particular, I presented the purpose and characteristic of HERA, explained how I can model and simulate the electromagnetic and electrical properties of the HERA antenna and the RF analogue chain, along with the systematics which affect the received signal and its impact on the EoR detection. Lastly, I answered the questions of the audience. |
| Year(s) Of Engagement Activity | 2017 |
| URL | https://www.acru.ukzn.ac.za/~cosmosafari2017/ |
| Description | Talk during the Astrophysics group seminar (Cambridge) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Study participants or study members |
| Results and Impact | During the weekly seminar organised in the Astrophysics group, I gave a 25-min presentation about my research. In particular, I explained how I can model and simulate the electromagnetic and electrical properties of the HERA antenna and the RF analogue chain, along with the systematics which affect the received signal, and its impact on the EoR detection. I also presented a new feed design which will replace the current system in order to increase the antenna bandwidth, improve its response and its sensitivity. Lastly, I answered the questions of the audience. |
| Year(s) Of Engagement Activity | 2017 |
| Description | Talk during the Global Altair Technology Conference (Paris) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | -Talks about the importance of electromagnetic simulations in the development of radio-telescopes. -Audience: ~50 professionals working in industry -Outcome: technical questions and discussion |
| Year(s) Of Engagement Activity | 2018 |
| URL | https://altairatc.com/paris2018/ |
| Description | Talk during the International Conference on Electromagnetics in Advanced Applications (ICEAA) (Australia) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | 20-min presentation about my research during ICEAA. In particular, I presented the purpose and characteristic of HERA, explained how I can model and simulate the electromagnetic and electrical properties of the HERA antenna and the RF analogue chain, along with the systematics which affect the received signal. Lastly, I answered the questions of the audience. |
| Year(s) Of Engagement Activity | 2016 |
| URL | http://www.iceaa-offshore.org/j3/ |
| Description | Talk during the URSI Atlantic Radio Science Meeting (Canary Islands) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | -Talk about the chromatic effects in HERA including mutual coupling and RF electronics -Audience: ~ 80 persons -Outcomes: technical questions |
| Year(s) Of Engagement Activity | 2018 |
| URL | http://www.atrasc.com/homepage.php |
| Description | Talk during the URSI UK Festival of Radio Science (Bradford) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Postgraduate students |
| Results and Impact | For 25 minutes, I gave a presentation about HERA, how I model and simulate the electromagnetic and electrical properties of the antenna and the RF analogue chain, along with the systematics which affect the received signal and its impact of the EoR detection. I also presented a new feed design which will replace the current system in order to increase the antenna bandwidth, improve its response and its sensitivity. |
| Year(s) Of Engagement Activity | 2017 |
| Description | Talk for the Cambridge University Astronomical Society |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Public/other audiences |
| Results and Impact | -General talk about radio-astronomy and radio-telescopes -Audience: ~ 30 persons -Outcome: general questions |
| Year(s) Of Engagement Activity | 2019 |
| URL | https://astronomy.soc.srcf.net/ |