The University College London Positronium Spectroscopy group. Researching antimatter, gravity and QED.
Bloomsbury, London
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Last week we attended the PSAS 2024 conference at @ETH_en Zurich. Thank you to the organisers for a great #conference and for letting us present our work. Our posters can be downloaded on our website. #Zurich #physics #science #antimatter #travel #presentation #UCL #research
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Last week we held the UK Positron Meeting 2024 at @ucl. We had over thirty attendees presenting #positron #research taking place all across the country. Thanks you to all those who attended, and see you in Swansea next year! #conference #physics #presentation #UK #powerpoint #PhD
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This is a simulated #microwave pulse propagating into our vacuum chamber where we excite #positronium #atoms to test QED. The pulse takes a long time to die down and this can cause #problems. But horn #antenna have other advantages we make use of. #Simulation #PhD #GIF #Animation
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We've got a new #blog post about some #work we did last year with horn #antenna and #positronium. Our blog contains more accessible versions of our published #research so check it out. #physics #content #antimatter #microwaves #PhD antimattergravity.com/2024/0…
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This setup is designed to field ionise Rydberg #helium. A large electric field deforms the coulomb #potential well of the atom. If it deforms low enough in energy the excited #electron can just 'fall out' of the well. It can also #quantum tunnel through the potential barrier.#phd
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Check out the new article on our website about how you can go from undergrad molecular #chemistry to a PhD in #antimatter physics.#physics #science #PhD #blog #molecule #atom #studentlife #ucl antimattergravity.com/2024/0…
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The newest tube line... These pipes from @Swagelok are used to make high pressure gas and water lines in our #antimatter experiments. #photo #engineering #plumbing #lighting #hashtag
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This is a positron accumulator. The ring electrodes are biased to #trap the charged #antimatter in the centre, building up more and more #positrons. The electrodes are #gold plated to give very uniform electric fields. #physics #science #experiment #research #PhD #particlephysics
ALT A set of 20 one inch diameter, tightly spaced gold rings.
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The #glowing metal is heated to remove surface contaminants. The tube on the right is an #electron gun and retarding field analyser for Auger electron #spectroscopy (AES). This technique identifies contaminents on the surface from unique #energy signatures of reflected electrons.
ALT A glowing metal sample mounted on a heater (left). An Auger spectrometer (right). All within a metal vacuum chamber.
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This glowing phosphor screen is for low-energy #electron diffraction (LEED). We can see diffraction patterns that depend on the atomic structure of a #crystal. We use this to check the surface of single crystal metal #positronium production targets for dirt.#physics #PhD #quantum
ALT A glowing round green screen inside a metal vacuum tube.
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These electrodes were used to create a uniform #electric field to measure the lifetime of the 2P state of #positronium. The 2P lifetime is just 3ns, which we can't directly observe, so we must mix it with the longer lived 2S state using the #applied field. #physics #science #PhD
ALT Three shiny metal electrodes suspended from a vacuum flange with a lab in the background.
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This is the inside of an @Agilent scroll pump. These pumps help us achieve the vacuum in our #experiment. It shouldn't look dusty like this but over time the seals wear out and need to be replaced as these can run for 24/7 for years. #physics #PhD #cleaning #technology #science
ALT The grimy insides of a long used, oil free pump.
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This is an oxygen free copper mount for our #radioactive source. The source is inserted into the back and cooled to 6K. Neon gas is frozen onto the conical aperture at the front. This converts the very fast beta+ #radiation into slow positrons for #experiments. #physics #research
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The very tiny aperture you see in the centre of the metal plate emmits terahertz (THz) #radiation. We use this THz source from @vadiodes to measure the #energy interval between Rydberg states of #positronium and work out the Rydberg constant in a lepton only system. #physics #PhD
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