With the Penning trap mass spectrometer ISOLTRAP, located at ISOLDE/CERN, preparatory work has been performed towards mass and decay studies on neutron-rich Hg and Tl isotopes beyond
N
= 126 . The ...properties of these isotopes are not well known because of large isobaric contamination coming mainly from surface-ionised Fr. Within the studies, production tests using several target-ion source combinations were performed. It was furthermore demonstrated around mass number
A
= 209 that the resolving power required to purify Fr is achievable with ISOLTRAP. In addition, masses of several isobaric contaminants,
211-213
Fr and
211
Ra , were determined with a three-fold improved precision. The results influence masses of more than 20 other nuclides in the
208
Pb region.
Proposed antimatter gravity measurement with an antihydrogen beam Kellerbauer, A.; Amoretti, M.; Belov, A.S. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
02/2008, Letnik:
266, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The principle of the equivalence of gravitational and inertial mass is one of the cornerstones of general relativity. Considerable efforts have been made and are still being made to verify its ...validity. A quantum-mechanical formulation of gravity allows for non-Newtonian contributions to the force which might lead to a difference in the gravitational force on matter and antimatter. While it is widely expected that the gravitational interaction of matter and of antimatter should be identical, this assertion has never been tested experimentally. With the production of large amounts of cold antihydrogen at the CERN Antiproton Decelerator, such a test with neutral antimatter atoms has now become feasible. For this purpose, we have proposed to set up the AEGIS experiment at CERN/AD, whose primary goal will be the direct measurement of the Earth’s gravitational acceleration on antihydrogen with a classical Moiré deflectometer.
The performance of proposed antihydrogen spectroscopy or gravity experiments will crucially depend on the temperature of the initial antihydrogen sample. Measurements by ATRAP and ATHENA have shown ...that antihydrogen produced with the nested-trap technique is much hotter than the temperature of the surrounding trap. Therefore, novel schemes for antihydrogen recombination as well as for the pre-cooling of antiprotons are being considered. We are investigating a possible antiproton cooling technique based on the laser cooling of negative osmium ions. If demonstrated to be successful, it will allow the sympathetic cooling of antiprotons—or any negatively charged particles—to microkelvin temperatures. As a first milestone toward the laser cooling of negative ions, we have performed collinear laser spectroscopy on negative osmium and determined the transition frequency and the cross-section of the relevant bound–bound electric-dipole transition.
The main scientific goal of the AEGIS experiment (
Antimatter
Experiment:
Gravity,
Interferometry,
Spectroscopy) is the direct measurement of the Earth's gravitational acceleration
g on a beam of ...cold antihydrogen (
H
¯
). The production of an antihydrogen beam is achieved by a charge exchange reaction between Rydberg positronium and cold antiprotons. The
H
¯
beam will be accelerated up to a velocity of a few 100 m/s and the gravitational acceleration will be obtained by measuring the small vertical deflection of the beam (a few tens
μm) using a Moire' deflectometer.
The AEGIS experiment at CERN Kellerbauer, A.; Allkofer, Y.; Amsler, C. ...
Hyperfine interactions,
05/2012, Letnik:
209, Številka:
1-3
Journal Article
Recenzirano
After the first production of cold antihydrogen by the ATHENA and ATRAP experiments ten years ago, new second-generation experiments are aimed at measuring the fundamental properties of this ...anti-atom. The goal of AEGIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is to test the weak equivalence principle by studying the gravitational interaction between matter and antimatter with a pulsed, cold antihydrogen beam. The experiment is currently being assembled at CERN’s Antiproton Decelerator. In AEGIS, antihydrogen will be produced by charge exchange of cold antiprotons with positronium excited to a high Rydberg state (
n
> 20). An antihydrogen beam will be produced by controlled acceleration in an electric-field gradient (Stark acceleration). The deflection of the horizontal beam due to its free fall in the gravitational field of the earth will be measured with a moiré deflectometer. Initially, the gravitational acceleration will be determined to a precision of 1%, requiring the detection of about 10
5
antihydrogen atoms. In this paper, after a general description, the present status of the experiment will be reviewed.
AEgIS (Antimatter experiment: gravity, interferometry, spectroscopy) is an experiment approved by CERN with the goal of studying antihydrogen physics. In AEgIS, antihydrogen will be produced by ...charge exchange reactions of cold antiprotons with positronium atoms excited in a Rydberg state (n > 20). In the first phase of the experiment, controlled acceleration by an electric field gradient (Stark effect) and subsequent measurement of free fall in a Moire deflectometer will allow a test of the weak equivalence principle. In a second phase, the antihydrogen will be slowed, confined, and laser-cooled to perform CPT studies and detailed spectroscopy. In the present work, after a general description of the experiment, the present status of advancement will be reviewed, with special attention to the production and excitation of positronium atoms.
The formation of the antihydrogen beam in the AEGIS experiment through the use of inhomogeneous electric fields is discussed and simulation results including the geometry of the apparatus and ...realistic hypothesis about the antihydrogen initial conditions are shown. The resulting velocity distribution matches the requirements of the gravity experiment. In particular it is shown that the inhomogeneous electric fields provide radial cooling of the beam during the acceleration.
AEgIS (Expérience sur l'Antimatière: Gravité, Interférométrie, Spectrométrie) est une expérience approuvée par le CERN qui vise une étude globale de la physique de l'anti-hydrogène. Dans AEgIS, ...l'anti-hydrogène sera produit par des réactions d'échange de charges d'anti-protons froids avec des atomes de positronium excités dans un état de Rydberg (n > 20). Dans la première phase de l'expérience, l'accélération est contrôlée par un gradient de champ électrique (effet Stark); une mesure subséquente en chute libre dans un déflectomètre de Moiré nous fournira un test du principe d'équivalence faible. Dans une deuxième phase, l'anti-hydrogène sera ralenti, confiné et refroidi par laser pour des études de CPT et de spectroscopie de précision. Après une description générale de l'expérience, nous passons ici en revue l'état d'avancement des travaux en accordant une attention particulière à la production et l'excitation des atomes de positronium.
AEgIS (Antimatter experiment: gravity, interferometry, spectroscopy) is an experiment approved by CERN with the goal of studying antihydrogen physics. In AEgIS, antihydrogen will be produced by ...charge exchange reactions of cold antiprotons with positronium atoms excited in a Rydberg state (n > 20). In the first phase of the experiment, controlled acceleration by an electric field gradient (Stark effect) and subsequent measurement of free fall in a Moiré deflectometer will allow a test of the weak equivalence principle. In a second phase, the antihydrogen will be slowed, confined, and laser-cooled to perform CPT studies and detailed spectroscopy. In the present work, after a general description of the experiment, the present status of advancement will be reviewed, with special attention to the production and excitation of positronium atoms.
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