High-resolution MCP-TimePix3 imaging/timing detector for antimatter physics

We present a hybrid imaging/timing detector for force sensitive inertial measurements designed for measurements on positronium, the metastable bound state of an electron and a positron, but also suitable for applications involving other low intensity, low energy beams of neutral (antimatter)-atoms, such as antihydrogen. The performance of the prototype detector was evaluated with a tunable low energy positron beam, resulting in a spatial resolution of approximate t

Development of a detector for inertial sensing of positronium at AEgIS (CERN)

The primary goal of the AEgIS collaboration at CERN is to measure the gravitational acceleration on neutral antimatter. Positronium (Ps), the bound state of an electron and a positron, is a suitable candidate for a force-sensitive inertial measurement by means of deflectometry/interferometry. In order to conduct such an experiment, the impact position and time of arrival of Ps atoms at the detector must be detected simultaneously. The detection of a low-velocity Ps beam with a spatial resolution of (88 ± 5) μm was previously demonstrated [1]. Based on the methodology employed in [1] and [2], a hybrid imaging/timing detector with increased spatial resolution of about 10 μm was developed. The performance of a prototype was tested with a positron beam. The concept of the detector and first results are presented

Control system for ion Penning traps at the AEgIS experiment at CERN

The AEgIS experiment located at the Antiproton Decelerator at CERN aims to measure the gravitational fall of a cold antihydrogen pulsed beam. The precise observation of the antiatoms in the Earth gravitational field requires a controlled production and manipulation of antihydrogen. The neutral antimatter is obtained via a charge exchange reaction between a cold plasma of antiprotons from ELENA decelerator and a pulse of Rydberg positronium atoms. The current custom electronics designed to operate the 5 and 1 T Penning traps are going to be replaced by a control system based on the ARTIQ & Sinara open hardware and software ecosystem. This solution is present in many atomic, molecular and optical physics experiments and devices such as quantum computers. We report the status of the implementation as well as the main features of the new control system

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

Techniques for production and detection of 23S positronium

In this work, we show recent measurements of 23S long-lived positronium production via spontaneous decay from the 33P level. The possibility to tune the velocity of the 23S positronium, excited following this scheme, is presented. In the light of these results, we discuss the use of the 33P→23S transition to realize a monochromatic pulsed 23S positronium beam with low angular divergence. Preliminary tests of 23S beam production are presented. The possibility to overcome the natural 33P→23S branching ratio via stimulated emission, and thus increasing the intensity of the 23S source, is also shown. A position-sensitive detector for a pulsed beam of positronium, with spatial resolution of ≈ 90 μm, is finally described in view of its possible application for the spatial characterization of the 23S beam

Forward emission of positronium from nanochanneled silicon membranes

Positronium beam formation and manipulation are required in several fundamental experiments. Efficient positron/positronium conversion in transmission configuration would offer important geometrical advantages over the reflection one for these applications. A novel type of transmission positron/positronium converters, which consists of silicon membranes with pass-through nanochannels, was produced and tested. The amount of forward emitted positronium was studied as a function of the thickness of the membranes and the nanochannel size. A maximum of, at least, (16\ub14)% of positrons implanted in (3.5\ub10.5)-\u3bcm-thick membrane with a nanochannel size of 5-8 nm were found to be forward emitted as positronium. A similar maximum amount of, at least, (16\ub15)%, was found to be emitted from a membrane (7.7\ub11.3)-\u3bcm-thick with a nanochannel size of 7-10 nm. A preliminary evaluation shows that the maximum amount of forward emitted positronium with the entire kinetic energy distribution below 1 eV is, at least, 9% of the positrons implanted in the (3.5\ub10.5)-\u3bcm-thick membrane

Pulsed production of antihydrogen

Antihydrogen atoms with K or sub-K temperature are a powerful tool to precisely probe the validity of fundamental physics laws and the design of highly sensitive experiments needs antihydrogen with controllable and well defined conditions. We present here experimental results on the production of antihydrogen in a pulsed mode in which the time when 90% of the atoms are produced is known with an uncertainty of ~250 ns. The pulsed source is generated by the charge-exchange reaction between Rydberg positronium atoms—produced via the injection of a pulsed positron beam into a nanochanneled Si target, and excited by laser pulses—and antiprotons, trapped, cooled and manipulated in electromagnetic traps. The pulsed production enables the control of the antihydrogen temperature, the tunability of the Rydberg states, their de-excitation by pulsed lasers and the manipulation through electric field gradients. The production of pulsed antihydrogen is a major landmark in the AEḡIS experiment to perform direct measurements of the validity of the Weak Equivalence Principle for antimatter

High-yield thermalized positronium at room temperature emitted by morphologically tuned nanochanneled silicon targets

Nanochanneled silicon targets with high positron/positronium (Ps) conversion rate and efficient Ps cooling were produced. Morphological parameters of the nanochannels, such as their diameter and length, were adjusted to get a large fraction of thermalized Ps at room temperature being emitted into vacuum. Ps cooling measurements were conducted combining single-shot positron annihilation lifetime spectroscopy and Doppler spectroscopy of the 13S → 23P transition. 2γ-3γ annihilation ratio measurements were also performed to estimate the positron/Ps conversion efficiency. In a converter with nanochannel diameter of 7-10 nm and depth of 3.89 μm, ∼28% of implanted positrons with an energy of 3.3 keV was found to be emitted as Ps with a transverse kinetic energy of 11 ± 2 meV. The reduction of the nanochannels depth to 1.13 μm, without changing the nanochannel diameter, was found to result in a less efficient cooling, highlighting the presence of Ps reflection from the bottom end of nanochannels