UCL Ps Spectroscopy

The University College London Positronium Spectroscopy group. Researching antimatter, gravity and QED.

[UCL Ps Spectroscopy @PsSpectroscopy]

Our group at the #SLOPOS 16 conference in #Orleans.
#UCL #physics

[UCL Ps Spectroscopy @PsSpectroscopy]

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

[UCL Ps Spectroscopy @PsSpectroscopy]

The clock in our #lab is an #antimatter clock. Antimatter is considered to go backwards in time, hence the #clock ticks backwards. It has never ever caused any #confusion. Ever.
#time #physics #science #backwards #research #weird #odd #amazing #cool #PhD #quantum #UCL

[UCL Ps Spectroscopy @PsSpectroscopy]

Don't you hate it when your electromagnet is gets so hot so you have to borrow every fan in the building and rig up an improvised table. Stay tuned to see if it melts itself! #experiment #research #PhD #antimatter #science #diy #problem #melt #magnet #UCL #physics

[UCL Ps Spectroscopy @PsSpectroscopy]

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

[UCL Ps Spectroscopy @PsSpectroscopy]

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

[UCL Ps Spectroscopy @PsSpectroscopy]

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 https://t.co/k4QrijOYnK

[UCL Ps Spectroscopy @PsSpectroscopy]

The glowing violet-white spot after this lens is the air itself ionising due to a highly focused infrared laser beam. That wasn't meant to happen, but it's really cool nonetheless. #physics #science #experiment #research #PhD #glowing #laser #photo #air #atmosohere #laser #UCL

[UCL Ps Spectroscopy @PsSpectroscopy]

Our new hybrid positron #beam is coming to life. The #vacuum system for the #positron buffer gas trap is built, and the coldhead for the #radioactive source is assembled. This can reach just 4K and freeze neon solid. #physics #UCL #PhD #phdlife #diy #science #research #stem

[UCL Ps Spectroscopy @PsSpectroscopy]

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

[UCL Ps Spectroscopy @PsSpectroscopy]

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 https://t.co/HyuDTAfxLs

[UCL Ps Spectroscopy @PsSpectroscopy]

This is an electrostatic quadrupole guide which confines #Rydberg atoms over long distances with minimal loses. The large electric dipole moment of Rydberg #atoms means that they can fall down or up an #electric field gradient, like the one used to confine them in the guide. #PhD

[UCL Ps Spectroscopy @PsSpectroscopy]

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

[UCL Ps Spectroscopy @PsSpectroscopy]

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

[UCL Ps Spectroscopy @PsSpectroscopy]

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.

[UCL Ps Spectroscopy @PsSpectroscopy]

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

[UCL Ps Spectroscopy @PsSpectroscopy]

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

[UCL Ps Spectroscopy @PsSpectroscopy]

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

[UCL Ps Spectroscopy @PsSpectroscopy]

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

[UCL Ps Spectroscopy @PsSpectroscopy]

For a long time THz radiation was hard to produce, falling between electronic and optical means of making light. But now THz sources are commercially available. This one has a wavelength of 0.3 mm at 0.874 THz, hence the teeny aperture. #UCL #quantum #rf #science #research #tech

[UCL Ps Spectroscopy @PsSpectroscopy]

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