Vibration Budget for SuperB

International audienceWe pre­sent a vi­bra­tion bud­get for the Su­perB ac­cel­er­a­tor. This in­cludes ground mo­tion data, mo­tion sen­si­tiv­i­ty of ma­chine com­po­nents, and beam feed­back sys­tem re­quire­ments

Antihydrogen studies in ALPHA

he ALPHA experiment studies antihydrogen as a means to investigate the symmetry of matter and antimatter. Spectroscopic studies of the anti-atom hold the promise of the most precise direct comparisons of matter and antimatter possible. ALPHA was the first to trap antihydrogen in a magnetic trap, allowing the first ever detection of atomic transitions in an anti-atom. More recently, through stochastic heating, we have also been able to put a new limit on the charge neutrality of antihydrogen. ALPHA is currently preparing to perform the first laser-spectroscopy of antihydrogen, hoping to excite the 2s state using a two-photon transition from the 1s state. We discuss the recent results as well as the key developments that led to these successes and discuss how we are preparing to perform the first laser-spectroscopy. We will also discuss plans to use our novel technique for gravitational tests on antihydrogen for a direct measurement of the sign of the gravitational force on antihydrogen

An ultracold low emittance electron source

Ultracold atom-based electron sources have recently been proposed as an alternative to the conventional photo-injectors or thermionic electron guns widely used in modern particle accelerators. The advantages of ultracold atom-based electron sources lie in the fact that the electrons extracted from the plasma (created from near threshold photo-ionization of ultracold atoms) have a very low temperature, i.e. down to tens of Kelvin. Extraction of these electrons has the potential for producing very low emittance electron bunches. These features are crucial for the next generation of particle accelerators, including free electron lasers, plasma-based accelerators and future linear colliders. The source also has many potential direct applications, including ultrafast electron diffraction (UED) and electron microscopy, due to its intrinsically high coherence. In this paper, the basic mechanism of ultracold electron beam production is discussed and our new research facility for an ultracold, low emittance electron source is introduced. This source is based on a novel alternating current Magneto-Optical Trap (the AC-MOT). Detailed simulations for a proposed extraction system have shown that for a 1 pC bunch charge, a beam emittance of 0.35 mm mrad is obtainable, with a bunch length of 3 mm and energy spread 1 %.Comment: 15 pages, 9 figures, to be published in Journal of Instrumentation in 201

First use of Timepix3 hybrid pixel detectors in ultra-high vacuum for beam profile measurements

A transverse beam gas ionization profile monitor is currently under development for the CERN Proton Synchrotron (PS) to provide non-destructive continuous measurements during a beam cycle. The implementation is exploring a novel use of the Timepix3 hybrid pixel detector mounted inside the ultra-high vacuum of the accelerator beam pipe to provide direct detection of ionization electrons. In early 2017, a prototype monitor was installed and has been used successfully to measure the transverse beam profile. The evolution of the transverse beam profile throughout the beam cycle has been measured and specific time windows within a beam cycle have been studied, for example the transition crossing. A radiation tolerant readout system for the Timepix3 detectors has been implemented which enables the connection of up to four detectors located in a highly radioactive environment. The first version of the readout was installed together with the prototype monitor in 2017 and a new version of the readout is currently under development which will enable the full speed data rate of the pixel detectors. Use of the radiation tolerant readout system can be envisioned for other beam instrumentation applications, which could provide new insight to beam diagnostics

Production of antihydrogen at reduced magnetic field for anti-atom trapping

We have demonstrated production of antihydrogen in a 1$,$T solenoidal magnetic field. This field strength is significantly smaller than that used in the first generation experiments ATHENA (3$,$T) and ATRAP (5$,$T). The motivation for using a smaller magnetic field is to facilitate trapping of antihydrogen atoms in a neutral atom trap surrounding the production region. We report the results of measurements with the ALPHA (Antihydrogen Laser PHysics Apparatus) device, which can capture and cool antiprotons at 3$,$T, and then mix the antiprotons with positrons at 1$,$T. We infer antihydrogen production from the time structure of antiproton annihilations during mixing, using mixing with heated positrons as the null experiment, as demonstrated in ATHENA. Implications for antihydrogen trapping are discussed

Centrifugal separation and equilibration dynamics in an electron-antiproton plasma

Charges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally-separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally-separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result. Electron-antiproton plasmas play a crucial role in antihydrogen trapping experiments