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.

Publications

10 25 50
 
Description Cherenkov Telescope Array (CTA) 
Organisation Durham University
Department Department of Physics
Country United Kingdom of Great Britain & Northern Ireland (UK) 
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, French Republic 
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 of Great Britain & Northern Ireland (UK) 
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 of Great Britain & Northern Ireland (UK) 
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, Federal Republic of 
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, Federal Republic of 
Sector Public 
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, Commonwealth of 
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, Kingdom of the 
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, French Republic 
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 of Great Britain & Northern Ireland (UK) 
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, Federal Republic of 
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, Federal Republic of 
Sector Public 
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, French Republic 
Sector Public 
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, French Republic 
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, Commonwealth of 
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, Kingdom of the 
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 of Great Britain & Northern Ireland (UK) 
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 of Great Britain & Northern Ireland (UK) 
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 of Great Britain & Northern Ireland (UK) 
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