QUPLAS

QUPLAS (QUantum interferometry and gravity with Positrons and LASers)

NEWS 

04.12.19: The antimatter interferometry experiment performed in our laboratory is one of the Top 10 Breakthrough 2019 (physicsword).

03.05.19: First demonstration of antimatter wave interferometry

Authors of this work: S. Sala, A. Ariga, A. Ereditato, R. Ferragut, M. Giammarchi, M. Leone, C. Pistillo and P. Scampoli

Animation based on actual data

The first stage of the experiment aims at the comparison of positrons and electrons interference, to compare for the first time the quantum interferometry pattern of a particle with the one of its own antiparticle. To achieve this goal, a dedicated interferometer is being assembled at the VEPAS (Variable Energy Positron Annihilation Spectroscopy) positron beamline located at the L-NESS (Laboratory for Nanostructure Epitaxy and Spintronics on Silicon) Laboratory of the Politecnico di Milano in Como (Italy).

The scientific goal of the QUPLAS (QUantum interferometry and gravity with Positrons and LASers) antimatter experiment is the opening of two new fields of investigation in modern particle physics: antimatter interferometry, using both an elementary antiparticle (the positron, e+) and a bound e+/e- state (positronium, Ps), to test the validity of the fundamental CPT symmetry, and gravitation studies with positronium, an innovative way to inspect the Weak Equivalence Principle with a particle/antiparticle symmetric system.

Partial view of the positron interferometer

Aki Ariga and Ciro Pistillo

Antonio Ereditato

Paola Scampoli

         Simone Sala

Micrograph of the emulsion containing the open regions of one of the gratings.

The periodicity of the positrons signal is clearly visible (see Aghion et al. JINST 13, P05013 (2018)

          Rafael Ferragut and Marco Leone        

 Ciro Pistillo and Marco Giammarchi

Contrast as a function of energy

Experimental set-up

Elena Tonello, Stefano Aghion and Francesco Barantani (2016)

One of the gratings that are used in the QUPLAS experiment for positron interferometer

Schematics of the Talbot-Lau interferometer

Contrast on the emulsion surface

More details available in these articles:

More information: some presentations

PhD Thesis: Simone Sala: QUPLAS: TOWARDS ANTIMATTER INTERFEROMETRY

QUPLAS Spokesperson: M.Giammarchi, INFN Milano

1) Vacuum chamber containing the interferometer and the mu-metal shield. 2) Vacuum system. 3) x-y stage moving the absorbing target for beam size measurement. 4) Viewport for laser alignment. 5) BaF2 detector. 6) Beam control electronics. 7) Bellows used for the alignment of the interferometer chamber.

A continuous positron beam is used to produce Talbot-Lau interference by means of micrometric gratings. The particle detection relies on the employment of emulsion based high-precision position detectors, which are being developed by the physicists of the Bern group in QUPLAS. Pictures of the first interferometer prototype and the micrometric gratings are presented in this page.An intensive R&D program has been conducted by the whole collaboration to assess the detectability of very low energy particles with emulsions and the capability to detect positrons at the keV energy scale has been successfully demonstrated.