20 research outputs found
Beam Coupling Impedance Measurement and Mitigation for a TOTEM Roman Pot
The longitudinal and transverse beam coupling impedance of the first final
TOTEM Roman Pot unit has been measured in the laboratory with the wire method.
For the evaluation of transverse impedance the wire position has been kept
constant, and the insertions of the RP were moved asymmetrically. With the
original configuration of the RP, resonances with fairly high Q values were
observed. In order to mitigate this problem, RF-absorbing ferrite plates were
mounted in appropriate locations. As a result, all resonances were sufficiently
damped to meet the stringent LHC beam coupling impedance requirements.Comment: 3 pages, 8 figures, proceedings of the 11th European Particle
Accelerator Conference (EPAC08), Genova, Italy, June 200
Trap-integrated fluorescence detection based on silicon photomultipliers in a cryogenic Penning trap
We present a fluorescence-detection system for laser-cooled 9Be+ ions based
on silicon photomultipliers (SiPM) operated at 4 K and integrated into our
cryogenic 1.9 T multi-Penning-trap system. Our approach enables fluorescence
detection in a hermetically-sealed cryogenic Penning-trap chamber with limited
optical access, where state-of-the-art detection using a telescope and
photomultipliers at room temperature would be extremely difficult. We
characterize the properties of the SiPM in a cryocooler at 4 K, where we
measure a dark count rate below 1/s and a detection efficiency of 2.5(3) %. We
further discuss the design of our cryogenic fluorescence-detection trap, and
analyze the performance of our detection system by fluorescence spectroscopy of
9Be+ ion clouds during several runs of our experiment.Comment: 12 pages, 11 figure
It’s (Not) Just a Figure of Speech: Rescuing Metaphor
Look for ways that students can study metaphor in everyday language, rather than confine its study to poetry
Development of a cold atomic muonium beam for next generation atomic physics and gravity experiments
A high-intensity, low-emittance atomic muonium (M) beam is being developed, which would enable improving the precision of M spectroscopy measurements, and may allow a direct observation of the M gravitational interaction. Measuring the free fall of M atoms would be the first test of the weak equivalence principle using elementary antimatter (ÎĽ+) and a purely leptonic system. Such an experiment relies on the high intensity, continuous muon beams available at the Paul Scherrer Institute (PSI, Switzerland), and a proposed novel M source. In this paper, the theoretical motivation and principles of this experiment are described.ISSN:2666-400
Particle detectors for the future antiproton Paul trap of the ASACUSA experiment at CERN
Beam profile monitor for annihilation cross section measurements of antiprotons at 100 keV
The ASACUSA (the Atomic Spectroscopy And Collisions Using Slow Antiprotons) collaboration is planning to measure the cross sections of antiproton annihilations at kinetic energy 100 keV on targets of various mass numbers (C, Ni, Sn, and Pt) using the Antiproton Decelerator (AD) of CERN. No previous measurement exists in this region where the A-dependence of the cross section is expected to deviate from the A2/3(Batty et al, Nucl Phys A 689:721, 2001) as reported by the Obelix collaboration. A beam profile monitor based on secondary electron emission with a grid of electrode pads fabricated on an FR4-type glass-epoxy circuit board was developed for this measurement. The advantage of this kind of detector is that it is simple, lightweight, and low cost. It was used to measure the spatial profile of 100-ns-long beam pulses containing > 6
7 104antiprotons with an active area of 40 mm
7 40 mm and a spatial resolution of 4 mm. \ua9 2011 Springer Science+Business Media B.V
Studying antimatter gravity with muonium
The gravitational acceleration of antimatter, gÂŻ, has yet to be directly measured; an unexpected outcome of its measurement could change our understanding of gravity, the universe, and the possibility of a fifth force. Three avenues are apparent for such a measurement: antihydrogen, positronium, and muonium, the last requiring a precision atom interferometer and novel muonium beam under development. The interferometer and its few-picometer alignment and calibration systems appear feasible. With 100 nm grating pitch, measurements of gÂŻ to 10%, 1%, or better can be envisioned. These could constitute the first gravitational measurements of leptonic matter, of 2nd-generation matter, and possibly, of antimatter.ISSN:2218-200