The goal of the AEḡIS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth’s gravitational acceleration on antimatter by measuring the free fall of a pulsed, cold antihydrogen beam. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1% precision on the measurement of ḡ with about 600 reconstructed and time tagged annihilations. We present here the prospects for the development of the AEḡIS silicon position sentive detector and the results from the first beam tests on a monolithic silicon pixel sensor, along with a comparison to Monte Carlo simulations.

The AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) experiment is located at the antiproton decelerator complex of CERN. The main goal of the experiment is to perform the first direct measurement of the Earth's gravitational acceleration on antihydrogen atoms within 1% precision. The antihydrogen is produced in a cylindrical Penning trap by combining antiprotons with positrons. To reach the precision of 1%, the antihydrogen has to be cooled to 100 mK to reduce its random velocity. A dilution refrigerator is selected to deliver the necessary cooling capacity of 100 mu W at 50 mK. The AEgIS cryogenic system basically consists of cryostats for a 1-T and for a 5-T superconducting magnet, a central region cryostat, a dilution refrigerator cryostat and a measurement cryostat with a Moire deflectometer to measure the gravitational acceleration. In autumn 2012, the 1-T cryostat, 5-T cryostat and central region cryostat were assembled and commissioned. The apparatus is cooled down in eight days using 2500 L of liquid helium and liquid nitrogen. During operation, the average consumption of liquid helium is 150 L.day(-1) and of liquid nitrogen 5 L.day(-1). The temperature sensors at the Penning traps measured 12 K to 18 K, which is higher than expected. Simulations show that this is caused by a bad thermalization of the trap wiring. The implementation of the sub-kelvin region is foreseen for mid-2015. The antihydrogen will be cooled down to 100 mK in an ultra-cold trap consisting of multiple high-voltage electrodes made of sapphire with gold plated electrode sectors.

The goal of the AEgIS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter by measuring the free fall of a pulsed, cold antihydrogen beam. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1% precision on the measurement of (g) over bar with about 600 reconstructed and time tagged annihilations. We present here the prospects for the development of the AEgIS silicon position sentive detector and the results from the first beam tests on a monolithic silicon pixel sensor, along with a comparison to Monte Carlo simulations.

We present here a new application of silicon sensors aimed at the direct detection of arainucleons annihilations taking place inside the sensor's volume. Such detectors are interesting particularly for the measurement of antimatter properties and will be used as part of the gravity measurement module in the AET1S experiment at the CERN Antiproton Decelerator. One of the goals of the AETIS experiment is to measure the gravitational acceleration of araihydrogen with 1% precision. Three different silicon sensor geometries have been tested with an antiproton beam to investigate their properties as annihilation detection devices: strip planar, 3D pixels and monolithic pixel planar. In all cases we were successfully detecting annihilations taking place in the sensor and we were able to make a first characterization of the clusters and tracks. (C) 2014 Elsevier B.V. All rights reserved,

The goal of the AE$\mathrm{\bar{g}}$IS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter. To achieve this goal, the AE$\mathrm{\bar{g}}$IS collaboration will produce a pulsed, cold (100 mK) antihydrogen beam with a velocity of a few 100 m/s and measure the magnitude of the vertical deflection of the beam from a straight path. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1$%$ precision on the measurement of $\bar{g}$ with about 600 reconstructed and time tagged annihilations. We present here, to the best of our knowledge, the first direct measurement of antiproton annihilation in a segmented silicon sensor, the first step towards designing a position sensitive silicon detector for the AE$\mathrm{\bar{g}}$IS experiment. We also present a first comparison with Monte Carlo simulations (GEANT4) for antiproton energies below 5 MeV

The AEgIS Experiment is an international collaboration based at CERN whose aim is to perform the first direct measurement of the gravitational acceleration g of antihydrogen in the gravitational field of the Earth. Cold antihydrogen will be produced with a pulsed charge exchange reaction in a cylindrical Penning trap where antiprotons will be cooled to 100 mK. The cold antihydrogen will be produced in an excited Rydberg state and subsequently formed into a beam. The deflection of the antihydrogen beam will be measured by using Moire deflectometer gratings. After being approved in late 2008, AEgIS started taking data in a commissioning phase early 2012. This report presents an overview of the AEgIS experiment, describes its current status and shows the first measurements on antiproton catching and cooling in the 5 T Penning catching trap. We will also present details on the techniques needed for the 100 mK antihydrogen production, such as pulsed positronium production and its excitation with lasers.

The main goal of the AEgIS experiment at CERN is to test the weak equivalence principle for antimatter. We will measure the Earth's gravitational acceleration g¯ with antihydrogen atoms being launched in a horizontal vacuum tube and traversing a moiré deflectometer. We intend to use a position sensitive device made of nuclear emulsions (combined with a time-of-flight detector such as silicon μ-strips) to measure precisely their annihilation points at the end of the tube. The goal is to determine g¯ with a 1% relative accuracy. In 2012 we tested emulsion films in vacuum and at room temperature with low energy antiprotons from the CERN antiproton decelerator. First results on the expected performance for AEgIS are presented.

The aim of the AEg̅IS experiment is to measure the gravitational acceleration for anti-hydrogen in the Earth's gravitational field, thus testing the Weak Equivalence Principle, which states that all bodies fall with the same acceleration independent of their mass and composition. AEg̅IS will make use of a gravity module which includes a silicon detector, in order to measure the deflection of anti-hydrogen from a straight path due to the Earth's gravitational field, by detecting the annihilation position on its surface. A position resolution better than 10 μm is required to determine the gravitational acceleration with a precision better than 10%. The work presented here is part of a study of different silicon sensor technologies to realise a silicon anti-hydrogen detector for the AEg̅IS experiment at CERN. We here focus on the study of a 3D pixel sensor with FE-I4 readout, originally designed for the ATLAS detector at the LHC, and compare it to a previous monolithic planar detector studied, the MIMOTERA. The direct annihilation of low energy anti-protons (~ 100 keV) takes place in the first layers and we show that the charged annihilation products (pions and nuclear fragments) can be detected by such a sensor. The present study aims at understanding the signature of an annihilation event in a 3D silicon sensor, in order to assess the accuracy that can be achieved by such a sensor in the reconstruction of the position of annihilation, when the same happens directly on the detector surface. We also present a comparison between experimental data and GEANT4 simulations and previous data obtained with a silicon imaging detector. These results are being used to determine the geometrical and process parameters to be adopted by the silicon annihilation detector to be installed in AEg̅IS.

The AEgIS experiment is an interdisciplinary collaboration between atomic, plasma and particle physicists, with the scientific goal of performing the first precision measurement of the Earth's gravitational acceleration on antimatter. The principle of the experiment is as follows: cold antihydrogen atoms are synthesized in a Penning-Malmberg trap and are Stark accelerated towards a moiré deflectometer, the classical counterpart of an atom interferometer, and annihilate on a position sensitive detector. Crucial to the success of the experiment is an antihydrogen detector that will be used to demonstrate the production of antihydrogen and also to measure the temperature of the anti-atoms and the creation of a beam. The operating requirements for the detector are very challenging: it must operate at close to 4 K inside a 1 T solenoid magnetic field and identify the annihilation of the antihydrogen atoms that are produced during the 1 μs period of antihydrogen production. Our solution—called the FACT detector—is based on a novel multi-layer scintillating fiber tracker with SiPM readout and off the shelf FPGA based readout system. This talk will present the design of the FACT detector and detail the operation of the detector in the context of the AEgIS experiment.

The antimatter experiment AEGIS is being constructed at CERN. Its scientific goal is to measure the gravitational interaction between antimatter and ordinary matter. Therefore neutral antihydrogen is subjected to the earth's gravitational field. In order to perform precise measurements, the antihydrogen needs to be produced at very low temperatures. This is achieved by cooling the combining antiprotons to temperatures of about 100 mK.The antiprotons are trapped and cooled in a Penning trap. The required electrical fields are generated by a series of electrodes, which are charged independently with peak voltages of up to 1 kV. The electrodes are formed by thin gold layers sputtered onto polished sapphire. Sapphire provides reliable electrical insulation and very high thermal conductivity. The bottom of the sapphire is gold sputtered too and is pressed against the mixing chamber of a dilution refrigerator. An indium foil sandwiched between the sapphire and the mixing chamber is used to reduce the thermal boundary resistance.

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 moire 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.

Adiabatic Demagnetization Refrigerators (ADRs) are commonly used in cryogenic laboratories to achieve subkelvin temperatures. ADRs are also the technology of choice for several space borne instruments which make use of cryogenic microcalorimeters or bolometers [1-4]. For these applications, refrigerants with high ratios of cooling capacity to volume, or cooling capacity to mass are usually required. In this manuscript, two charts for the simple selection of the most suitable of several common refrigerants (CAA, CMN, CPA, DGG, FAA, GGG, GLF and MAS) are presented. These graphs are valid for single stage cycles. The selection of the refrigerants is uniquely dependent on the starting conditions of the refrigeration cycle (temperature and magnetic field density) and the desired final temperature. Only thermodynamic properties of the refrigerants have been taken into account, and other important factors such as availability and manufacturability have not been considered. (C) 2011 Elsevier Ltd. All rights reserved.

EURECA (European Underground Rare Event Calorimeter Array) is an astro-particle physics facility aiming to directly detect galactic dark matter. The Laboratoire Souterrain de Modane has been selected as host laboratory. The EURECA collaboration unites CRESST, EDELWEISS and the Spanish-French experiment ROSEBUD, thus concentrating and focussing effort on cryogenic detector research in Europe into a single facility. EURECA will use a target mass of up to one ton, enough to explore WIMP - nucleon scalar scattering cross sections in the region of 10(-9) - 10(-10) picobarn. A major advantage of EURECA is the planned use of more than just one target material (multi target experiment for WIMP identification).

EURECA (European Underground Rare Event Calorimeter Array) will be an astro-particle physics facility aiming to directly detect galactic dark matter. TheLaboratoire Souterrain de Modane has been selected as host laboratory. TheEURECA collaboration concentrates effort on cryogenic detector research inEurope into a single facility by bringing together colleagues from CRESST,EDELWEISS, ROSEBUD and additional new member institutes. EURECA will use atarget mass of up to one ton for exploring WIMP-nucleon scalar scattering crosssections in the region of 10 −9 – 10 −10 picobarn. A major advantage of EURECAis the planned use of more than just one target material (multi targetexperiment for WIMP identification).

English In-depth interviews were conducted with two samples of individuals (one in the US and one in South Africa) to explore their experiences with AIDS-related bereavement. Coping was influenced by similar factors though in different degrees. Thus, it is important that interventions be tailored to address these factors within each context. French Ce projet s'appuie sur des entrevues en profondeur qui ont été menées auprès de deux groupes de personnes aux États-Unis et en Afrique du Sud, et qui visaient à explorer leur expérience respective de deuil liée au Sida. Il en résulte que des facteurs similaires ont influencé leur façon de surmonter cette épreuve, dans une mesure toutefois différente. C'est pourquoi il est important que les interventions soient modulées afin de tenir compte de ces facteurs dans chacun des milieux. Spanish Se realizaron entrevistas en profundidad con dos muestras de individuos (una en los Estados Unidos y una en Sud Africa) para explorar sus experiencias con el sufrimiento relacionado con el SIDA. El enfrentamiento estuvo influenciado por factores similares aunque en diferentes grados. De tal manera, que es importante que las intervenciones se adapten para dirigirse a estos factores dentro de cada contexto.