9 Nuclear Emulsions
421
Fig. 9.25 An antiproton
annihilation vertex in an
emulsion layer [155]. The
view is perpendicular to the
antiproton beam direction
also reconstructed, demonstrating a resolution of 1 μm on the vertical position.
In addition, a proof-of-principle experiment with mini-moiré deflectometer was
performed [156]. The periodic patterns were observed as expected in the emulsions,
and the measured shift between antiprotons and light was consistent with the force
from the magnetic field at the given position. The results are a crucial step toward
the direct detection of the gravitational acceleration of antihydrogen. In 2014,
measurements of the multiplicities of charged annihilation products on different
target materials, namely copper, silver, and gold, were performed [157] at the CERN
AD. Apart from the obvious applications in nuclear physics, this measurement
can provide a useful check of the ability of standard Monte Carlo packages to
reproduce fragment multiplicities and energy distributions. The measured fragment
multiplicities were not well reproduced by the different models used in Monte Carlo
simulation with the exception of FLUKA [158, 159], which is in good agreement
with the particle multiplicities for both minimum and heavily ionizing particles
(Fig. 9.26).
There is another proposal by the QUantum interferometry and gravity with
Positrons and LASers (QUPLAS) project to use emulsions for their studies on
positrons [160]. The sensitivity of the emulsion detectors was studied using a monoenergetic positron beam at energies as low as 9–18 keV. The obtained results prove
that the emulsions are highly efficient at detecting positrons at these energies. This
achievement paves the way to perform matter-wave interferometry with positrons
using this technology.
421
Fig. 9.25 An antiproton
annihilation vertex in an
emulsion layer [155]. The
view is perpendicular to the
antiproton beam direction
also reconstructed, demonstrating a resolution of 1 μm on the vertical position.
In addition, a proof-of-principle experiment with mini-moiré deflectometer was
performed [156]. The periodic patterns were observed as expected in the emulsions,
and the measured shift between antiprotons and light was consistent with the force
from the magnetic field at the given position. The results are a crucial step toward
the direct detection of the gravitational acceleration of antihydrogen. In 2014,
measurements of the multiplicities of charged annihilation products on different
target materials, namely copper, silver, and gold, were performed [157] at the CERN
AD. Apart from the obvious applications in nuclear physics, this measurement
can provide a useful check of the ability of standard Monte Carlo packages to
reproduce fragment multiplicities and energy distributions. The measured fragment
multiplicities were not well reproduced by the different models used in Monte Carlo
simulation with the exception of FLUKA [158, 159], which is in good agreement
with the particle multiplicities for both minimum and heavily ionizing particles
(Fig. 9.26).
There is another proposal by the QUantum interferometry and gravity with
Positrons and LASers (QUPLAS) project to use emulsions for their studies on
positrons [160]. The sensitivity of the emulsion detectors was studied using a monoenergetic positron beam at energies as low as 9–18 keV. The obtained results prove
that the emulsions are highly efficient at detecting positrons at these energies. This
achievement paves the way to perform matter-wave interferometry with positrons
using this technology.