816 research outputs found
Nuclear emulsions for the detection of micrometric-scale fringe patterns: an application to positron interferometry
Nuclear emulsions are capable of very high position resolution in the
detection of ionizing particles. This feature can be exploited to directly
resolve the micrometric-scale fringe pattern produced by a matter-wave
interferometer for low energy positrons (in the 10-20 keV range). We have
tested the performance of emulsion films in this specific scenario. Exploiting
silicon nitride diffraction gratings as absorption masks, we produced periodic
patterns with features comparable to the expected interferometer signal. Test
samples with periodicities of 6, 7 and 20 {\mu}m were exposed to the positron
beam, and the patterns clearly reconstructed. Our results support the
feasibility of matter-wave interferometry experiments with positrons.Comment: 15 pages, 10 figure
Loss and revival of coherence in the interaction between a positron beam and a photon field
We study the interaction between a positron beam in the single-particle regime in an interferometric configuration and a microwave electromagnetic field. We discuss the conditions under which quantum interference can be affected by the field and we outline its possible experimental study in the framework of QUantum interferometry and gravitation
with Positrons and LASers (QUPLAS) experiment
Imaging low-energy positron beams in real-time with unprecedented resolution
Particle beams focused to micrometer-sized spots play a crucial role in
forefront research using low-energy positrons. Their expedient and wide
application, however, requires highly-resolved, fast beam diagnostics. We have
developed two different methods to modify a commercial imaging sensor to make
it sensitive to low-energy positrons. The first method consists in removing the
micro-lens array and Bayer filter from the sensor surface and depositing a
phosphor layer in their place. This procedure results in a detector capable of
imaging positron beams with energies down to a few tens of eV, or an intensity
as low as 35 particles/s/mm2 when the beam energy exceeds 10keV. The second
approach omits the phosphor deposition; with the resulting device we succeeded
in detecting single positrons with energies upwards of 6 keV and efficiency up
to 93%. The achieved spatial resolution of 0.97 micrometers is unprecedented
for real-time positron detectors.Comment: 18 pages, 6 figure
Low Energy Antimatter Physics
We will review the motivations and the general features of experiments devoted to testing fundamental laws with antimatter at low energies, namely the study of CPT invariance and the Weak Equivalence Principle. A summary of the recent experimental results will be presented
Upgrade of the positron system of the ASACUSA-Cusp experiment
The ASACUSA-Cusp collaboration has recently upgraded the positron system to
improve the production of antihydrogen. Previously, the experiment suffered
from contamination of the vacuum in the antihydrogen production trap due to the
transfer of positrons from the high pressure region of a buffer gas trap. This
contamination reduced the lifetime of antiprotons. By adding a new positron
accumulator and therefore decreasing the number of transfer cycles, the
contamination of the vacuum has been reduced. Further to this, a new rare gas
moderator and buffer gas trap, previously used at the Aarhus University, were
installed. Measurements from Aarhus suggested that the number of positrons
could be increased by a factor of four in comparison to the old system used at
CERN. This would mean a reduction of the time needed for accumulating a
sufficient number of positrons (of the order of a few million) for an
antihydrogen production cycle. Initial tests have shown that the new system
yields a comparable number of positrons to the old system.Comment: 10 pages, 5 figures, under consideration for the Special Collection
"Non-Neutral Plasmas: Achievements and Perspectives" in JP
Hybrid imaging and timing ps laser excitation diagnostics for pulsed antihydrogen production
open48siIn this work we present a hybrid detection method providing simultaneous imaging and timing information suitable for fully monitoring positronium (Ps) formation, its laser excitation, and its spatial propagation for the first trials of pulsed antihydrogen (H) production through a charge-exchange reaction with trapped antiprotons (p). This combined method, based on the synchronous acquisition of an EJ-200 scintillation detector and a microchannel plate (MCP) detector with a dual readout (phosphor screen image and electrical pick-up signal), allows all relevant events in the experiment to be accurately determined in time while allowing high resolution images of e+ from Ps laser photodissociations to be acquired. The timing calibration process of the two detectors discussed in details as well as the future perspectives opened by this method.openCaravita R.; Antonello M.; Belov A.; Bonomi G.; Brusa R.S.; Caccia M.; Camper A.; Castelli F.; Comparat D.; Consolati G.; Demetrio A.; Di Noto L.; Doser M.; Fani M.; Ferragut R.; Gerber S.; Giammarchi M.; Gligorova A.; Gloggler L.T.; Guatieri F.; Haider S.; Hinterberger A.; Khalidova O.; Krasnicky D.; Lagomarsino V.; Malbrunot C.; Mariazzi S.; Matveev V.; Muller S.R.; Nebbia G.; Nedelec P.; Oberthaler M.; Oswald E.; Pagano D.; Penasa L.; Petracek V.; Prelz F.; Rienacker B.; Rohne O.M.; Rotondi A.; Sandaker H.; Santoro R.; Testera G.; Tietje I.; Toso V.; Wolz T.; Zimmer C.; Zurlo N.Caravita, R.; Antonello, M.; Belov, A.; Bonomi, G.; Brusa, R. S.; Caccia, M.; Camper, A.; Castelli, F.; Comparat, D.; Consolati, G.; Demetrio, A.; Di Noto, L.; Doser, M.; Fani, M.; Ferragut, R.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Gloggler, L. T.; Guatieri, F.; Haider, S.; Hinterberger, A.; Khalidova, O.; Krasnicky, D.; Lagomarsino, V.; Malbrunot, C.; Mariazzi, S.; Matveev, V.; Muller, S. R.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Oswald, E.; Pagano, D.; Penasa, L.; Petracek, V.; Prelz, F.; Rienacker, B.; Rohne, O. M.; Rotondi, A.; Sandaker, H.; Santoro, R.; Testera, G.; Tietje, I.; Toso, V.; Wolz, T.; Zimmer, C.; Zurlo, N
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