Hot-Slumped Glass Mirrors for the Cherenkov Telescope Array
Lead Research Organisation:
University of Liverpool
Department Name: Physics
Abstract
Gamma ray astronomy studies very energetic radiation from many different astronomical objects, such as supernova remnants and black holes, as well as seeking to learn more about the fundamentals of the Universe, such as the nature of gravity. Gamma rays do not penetrate the Earth's atmosphere, but nonetheless we can detect them from the ground. It so happens that when a gamma-ray enters the atmosphere, it creates a cascade of highly energetic particles, which in turn produces a flash of light known as Cherenkov radiation. This consists of a faint, brief flash of blue/UV light, which telescopes known as Imaging Atmospheric Cherenkov Telescopes (IACTs) can detect. This technique has been shown to work well, and has revealed to us a sky full of particle accelerators far more powerful than the LHC. Scientists from around the world, including the UK, are now building an observatory for gamma ray astronomy, the Cherenkov Telescope Array, or CTA. This will consist of about 100 telescopes for observing the southern sky, located in Chile, and about 20 telescopes for studying the northern sky, sited in the Canary Islands. Three different sizes of telescope are needed, large, medium and small, for studying the lowest, intermediate and highest energy gamma rays, respectively. The site in Chile will have all three types of telescope, while only large and medium sized telescopes are needed in the Canary Islands, where the number of visible sources of the highest energy gamma rays is small.
There will be about 70 small sized telescopes in Chile. Scientists in the UK are leading the design and prototyping of a two-mirror design for these telescopes, known as the Gamma-ray Cherenkov Telescope (GCT). The mirrors for this telescope are challenging to make. All Cherenkov telescopes mirrors are concave in form. For the single-mirror telescopes that have been used until now, these have a very long focal length and the curvature of the mirrors is therefore small. This makes it possible to pull cold glass down onto a suitable mould to make the reflective surface. However, the GCT mirrors will have much greater curvature, and this makes it impossible to form cold glass to the correct shape. So, we are working with a company in St. Asaph in North Wales on a new technique to form the glass at high temperature. We have made some preliminary studies, which have been encouraging, and this grant application requests funds to take this process further, including creating the correct shape that we will need for the GCT and working with Thin Metal Films in Basingstoke to look at the best way of coating the mirror surfaces. If the project is successful, then UK companies will have a good chance of making mirrors not only for the GCT but also for an American-led dual-mirror telescope design being put forward as a medium size telescope for CTA.
There will be about 70 small sized telescopes in Chile. Scientists in the UK are leading the design and prototyping of a two-mirror design for these telescopes, known as the Gamma-ray Cherenkov Telescope (GCT). The mirrors for this telescope are challenging to make. All Cherenkov telescopes mirrors are concave in form. For the single-mirror telescopes that have been used until now, these have a very long focal length and the curvature of the mirrors is therefore small. This makes it possible to pull cold glass down onto a suitable mould to make the reflective surface. However, the GCT mirrors will have much greater curvature, and this makes it impossible to form cold glass to the correct shape. So, we are working with a company in St. Asaph in North Wales on a new technique to form the glass at high temperature. We have made some preliminary studies, which have been encouraging, and this grant application requests funds to take this process further, including creating the correct shape that we will need for the GCT and working with Thin Metal Films in Basingstoke to look at the best way of coating the mirror surfaces. If the project is successful, then UK companies will have a good chance of making mirrors not only for the GCT but also for an American-led dual-mirror telescope design being put forward as a medium size telescope for CTA.
Organisations
- University of Liverpool (Lead Research Organisation)
- Friedrich-Alexander University Erlangen-Nuremberg (Collaboration)
- UNIVERSITY OF LEICESTER (Collaboration)
- Nagoya University (Collaboration)
- Aix-Marseille University (Collaboration)
- UNIVERSITY OF OXFORD (Collaboration)
- National Center for Scientific Research (Centre National de la Recherche Scientifique CNRS) (Collaboration)
- Max Planck Society (Collaboration)
- DURHAM UNIVERSITY (Collaboration)
- GLYNDWR UNIVERSITY (Collaboration)
- University of Amsterdam (Collaboration)
- University of Adelaide (Collaboration)
- Observatory of Paris (Collaboration)
People |
ORCID iD |
Timothy Greenshaw (Principal Investigator) |
Publications
Zorn J
(2018)
Characterisation and testing of CHEC-M-A camera prototype for the small-sized telescopes of the Cherenkov telescope array
in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Acharyya A
(2019)
Monte Carlo studies for the optimisation of the Cherenkov Telescope Array layout
in Astroparticle Physics
Description | It is possible to shape thin glass to a mould using a carefully controlled temperature cycle. This allows, for example, the contruction of mirrors with aspherical shapes and small radii of curvature. With appropriate support structures, these could be used in telescopes for detecting Cherenkov light from the extensive air showers generated when very high energy photons enter the atmosphere. |
Exploitation Route | Could possible contribute to mirror production for the Cherenkow Telescope Array. Conceivably also of interest in solar power applicaitons (solar conentrators). |
Sectors | Aerospace Defence and Marine Energy |
Description | Cherenkov Telescope Array (CTA) |
Organisation | Durham University |
Department | Department of Physics |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Proposal of Dual Mirror design for Small Size Telescopes (SSTs) for CTA. First mechanical and optical designs of Dual Mirror SSTs. Leadership of SST project within CTA. Contributions to physics studies for CTA. Leadership for five years and then continuing contributions to overall array simulation and design. Leadership of outreach for CTA. Collaboration Board and Project Committee membership. |
Collaborator Contribution | Remainder of project with nearly 1500 physicists from 224 institutes in 33 coutries (as of March 2016), including: Design of Large, Medium and other Small Size Telescopes (LSTs, MSTs and SSTs, respectively). Studies of physics that CTA will carry out. Data processing for CTA. Site search and negotions, design of array infrastructure. Develoment of legal framework for CTA Observatory. |
Impact | Design of telescope sstructure, camera, and mirrors. Astrophsyics outreach in the UK and internationally. PhD students. |
Description | Cherenkov Telescope Array (CTA) |
Organisation | Observatory of Paris |
Country | France |
Sector | Academic/University |
PI Contribution | Proposal of Dual Mirror design for Small Size Telescopes (SSTs) for CTA. First mechanical and optical designs of Dual Mirror SSTs. Leadership of SST project within CTA. Contributions to physics studies for CTA. Leadership for five years and then continuing contributions to overall array simulation and design. Leadership of outreach for CTA. Collaboration Board and Project Committee membership. |
Collaborator Contribution | Remainder of project with nearly 1500 physicists from 224 institutes in 33 coutries (as of March 2016), including: Design of Large, Medium and other Small Size Telescopes (LSTs, MSTs and SSTs, respectively). Studies of physics that CTA will carry out. Data processing for CTA. Site search and negotions, design of array infrastructure. Develoment of legal framework for CTA Observatory. |
Impact | Design of telescope sstructure, camera, and mirrors. Astrophsyics outreach in the UK and internationally. PhD students. |
Description | Cherenkov Telescope Array (CTA) |
Organisation | University of Leicester |
Department | Department of Physics & Astronomy |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Proposal of Dual Mirror design for Small Size Telescopes (SSTs) for CTA. First mechanical and optical designs of Dual Mirror SSTs. Leadership of SST project within CTA. Contributions to physics studies for CTA. Leadership for five years and then continuing contributions to overall array simulation and design. Leadership of outreach for CTA. Collaboration Board and Project Committee membership. |
Collaborator Contribution | Remainder of project with nearly 1500 physicists from 224 institutes in 33 coutries (as of March 2016), including: Design of Large, Medium and other Small Size Telescopes (LSTs, MSTs and SSTs, respectively). Studies of physics that CTA will carry out. Data processing for CTA. Site search and negotions, design of array infrastructure. Develoment of legal framework for CTA Observatory. |
Impact | Design of telescope sstructure, camera, and mirrors. Astrophsyics outreach in the UK and internationally. PhD students. |
Description | Cherenkov Telescope Array (CTA) |
Organisation | University of Oxford |
Department | Department of Physics |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Proposal of Dual Mirror design for Small Size Telescopes (SSTs) for CTA. First mechanical and optical designs of Dual Mirror SSTs. Leadership of SST project within CTA. Contributions to physics studies for CTA. Leadership for five years and then continuing contributions to overall array simulation and design. Leadership of outreach for CTA. Collaboration Board and Project Committee membership. |
Collaborator Contribution | Remainder of project with nearly 1500 physicists from 224 institutes in 33 coutries (as of March 2016), including: Design of Large, Medium and other Small Size Telescopes (LSTs, MSTs and SSTs, respectively). Studies of physics that CTA will carry out. Data processing for CTA. Site search and negotions, design of array infrastructure. Develoment of legal framework for CTA Observatory. |
Impact | Design of telescope sstructure, camera, and mirrors. Astrophsyics outreach in the UK and internationally. PhD students. |
Description | Compact High Energy Camera |
Organisation | Friedrich-Alexander University Erlangen-Nuremberg |
Country | Germany |
Sector | Academic/University |
PI Contribution | Lead design and construction of camera for GCT telescope. |
Collaborator Contribution | Electronics testing. Software development. |
Impact | Design of camera. Prototype camera. |
Start Year | 2015 |
Description | Compact High Energy Camera |
Organisation | Max Planck Society |
Department | Max Planck Institute for Nuclear Physics |
Country | Germany |
Sector | Academic/University |
PI Contribution | Lead design and construction of camera for GCT telescope. |
Collaborator Contribution | Electronics testing. Software development. |
Impact | Design of camera. Prototype camera. |
Start Year | 2015 |
Description | Compact High Energy Camera |
Organisation | Nagoya University |
Country | Japan |
Sector | Academic/University |
PI Contribution | Lead design and construction of camera for GCT telescope. |
Collaborator Contribution | Electronics testing. Software development. |
Impact | Design of camera. Prototype camera. |
Start Year | 2015 |
Description | Compact High Energy Camera |
Organisation | University of Adelaide |
Country | Australia |
Sector | Academic/University |
PI Contribution | Lead design and construction of camera for GCT telescope. |
Collaborator Contribution | Electronics testing. Software development. |
Impact | Design of camera. Prototype camera. |
Start Year | 2015 |
Description | Compact High Energy Camera |
Organisation | University of Amsterdam |
Country | Netherlands |
Sector | Academic/University |
PI Contribution | Lead design and construction of camera for GCT telescope. |
Collaborator Contribution | Electronics testing. Software development. |
Impact | Design of camera. Prototype camera. |
Start Year | 2015 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | Aix-Marseille University |
Country | France |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | Durham University |
Department | Department of Physics |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | Friedrich-Alexander University Erlangen-Nuremberg |
Country | Germany |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | Max Planck Society |
Department | Max Planck Institute for Nuclear Physics |
Country | Germany |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | Nagoya University |
Country | Japan |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | National Center for Scientific Research (Centre National de la Recherche Scientifique CNRS) |
Department | IN2P3 CNRS |
Country | France |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | Observatory of Paris |
Country | France |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | University of Adelaide |
Country | Australia |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | University of Amsterdam |
Country | Netherlands |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | University of Leicester |
Department | Department of Physics & Astronomy |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Gamma-ray Cherenkov Telescope |
Organisation | University of Oxford |
Department | Department of Physics |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Design of the first mechanical structure of the GCT. Optical design of the GCT. Design and construction of multi-anode based compact high energy camera (CHEC) for the GCT, CHEC-M. Lab testing of CHEC-M. Installation of CHAC-M on the prototype telescope. Detection of air showers with the GCT and its camera. Testing of silicon photomultipliers (SiPMs) for the SiPM based GCT camera, CHEC-S. Design and test of the CHEC-S frant-end electronics. Contributions to simulation of the GCT and studies of physics using the GCT. |
Collaborator Contribution | Design of the prototype telescope structure. Construction of telescope on the Meudon site of the Paris Observatory. Construction of the GCT mirrors. Monte Carlo simulations for the GCT. Back end electronics for CHEC. |
Impact | Prototype telescope and camera for CTA. Publications. Outreach in Ile de France area. |
Start Year | 2014 |
Description | Mirrors for CTA |
Organisation | Glyndwr University |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Specification of mirrors |
Collaborator Contribution | Mirror construction process, test mirrors. |
Impact | Test mirrors for study of production process |
Start Year | 2015 |