W
elcome to the VEPAS laboratory
                                                        Variable Energy Positron Annihilation
                                                        Spectroscopy

The scientific goal of this 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.
To achieve this goal, a dedicated interferometer is being assembled in our VEPAS lab (more details).


AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy)

The VEPAS Lab participates to AEgIS. AEgIS is a physics experiment that takes place at the european laboratory CERN, using the antiprotons delivered by the AD accelerator. AEgIS is a collaboration of physicists from all around the world.
The primary scientific goal of the AEgIS experiment is the direct  measurement of the Earth’s gravitational acceleration g on antihydrogen. In the first phase of the experiment, a gravity measurement will be carried out by sending an antihydrogen beam through a classical moiré deflectometer coupled to a position sensitive detector. This will represent the first direct measurement of a gravitational effect on an antim
atter system
 (more details).
An efficient formation of cooled positronium atoms is a requisite for the production of antihydrogen in the AEgIS experiment. Porous materials are necessary to produce a high yield of Ps atoms as well as to cool Ps through collisions with the inner walls of the pores
.

AEgIS Milan group                   AEgIS CERN group                  AEgIS CERN

Research on Applicable Materials

Positron annihilation spectroscopy (PAS) is used to monitor thin hybrid solar cells in order to obtain depth-resolved data in collaboration with the Italian Institute of Technology (IIT) from Milan.
more details

News

22.06.19: THE MOST BEAUTIFUL EXPERIMENT: now with ANTIMATERIA

Event in Italian language

Nobel hall”, Istituto Carducci, Como


03.05.19: First demonstration of antimatter wave interferometry

It is the first version made with antimatter of the single particle interference experiment proposed by A. Einstein in 1927 and R. Feynman, for one of his famous lectures, and realized with electrons in 1976 by Merli, Missiroli and Pozzi, and in 1989 by A. Tonomura et al. This work has appeared on Science Advances and was realized by a collaboration that includes the Positron Laboratory of the Politecnico di Milano L-NESS in Como, where the experiment was performed. The others participating institutions are INFN (Milan unit), Università degli Studi di Milano, Università di Napoli Federico II and AEC & LHEP of the University of Bern. This is the first step of the QUPLAS (QUantum interferometry and gravity with Positrons and LASers) program.

Animation based on actual data showing the buildup of the interference pattern.

Quplas Milan group

Quplas Bern group

27.08.18: First observation of antimatter wave interference (preliminary version)

Media: ScienceAlert

            New Scientist pdf

            Futura Sciences

            Seeker

Recently in the Positron laboratory of Como, the first experimental evidence of antimatter interferometry with individual particles has been observed.

19.08.18: It was submitted a Memorial Text of Alfredo Dupasquier to the American Institute of Physics, Conference  Proceedings of the 18th Internation Conference on Positron Annihilation (Orlando, USA). Alfredo Dupasquier was a member of the “positron community” over a period of some 50 years and made substantial contributions to the science in this community. Here is a brief history of the Alfredo’s life related to his scientific and human contribution. pdf

02.03.15: The Positron Group has published (PNAS magazine) an advanced study on amorphous indium-gallium-zinc-oxide (IGZO) semiconductors in collaboration with the Group of Tobin Marks and Antonio Facchetti of the Northwestern University. In this work is demonstrated that the new coating technique, spray-combustion synthesis (SCS), produce IGZO films of excelent quality at low temperatures and for short times compared to the sputtering conventional technique.

28.07.14: The AEgIS collaboration at CERN has demonstrated a method to measure a very small deflection of an antimatter beam (smaller than the thickness of a human hair). The method has been tested by measuring the deviation of an antiproton beam (Nature Communications). 

25.05.13: La Fisica in Piazza (Milan)

07.05.13: The Positron Group has published an advanced review on Meoporous Materials for antihydrogen productionHydrophobic mesoporous silica with open pores such as MCM-41 and aerogel show remarkable features for antihydrogen formation at low temperature.

01.10.12: The Positron Group has published an advance study on Hybrid Solar Cells in collaboration with the IIT (Italian Institute of Technology).

17.04.12: L-NESS presentation (Italian: video)

16.03.12: The SiGe epitaxy group of L-NESS have made a Sience work on "Scaling Hetero-Epitaxy from Layers to Three-Dimensional Crystals" in collaboration with the ETH Zürich and Università di Milano-Bicocca. A photography of this work was selected for cover of Science.