Laboratory for High Energy Physics
In general relativity theory, the Weak Equivalence Principle (WEP) states the universality of a free fall. The AEgIS experiment will test the validity of the principle for antimatter measuring g̅ with a precision of 1%. It will be the first direct measurement of the Earth's gravitational acceleration on antimatter.
The AEgIS apparatus is being assembled at the Antiproton Decelerator facility at CERN. The detecting technique will be based on the reconstruction of the position of the annihilation point of antihydrogen atoms after their travel through a classical Moiré deflectometer in order to determine their trajectory in the Earth's gravitational field.
The precision of 1% for the measurement of g̅ requires the accuracy of 10 μm for the reconstruction of the position of the antihydrogen annihilation points. The submicrometric position resolution of nuclear emulsion make them a natural candidate for a position detector in AEgIS and the group of Bern is working at the design of an emulsion based tracking detector. An intense R&D is indeed being conducted at the LHEP laboratiories to improve the performances of current emulsions films and microscopes.