Theses

Be+-Assisted Antihydrogen Synthesis and Trapping Antihydrogen, the bound state of a positron and an antiproton, is a uniquely well-suited system for testing fundamental symmetries between matter and antimatter. The Antihydrogen Laser Physics Apparatus (ALPHA collaboration) synthesises antihydrogen atoms by slowly merging cold non-neutral positron and antiproton plasmas and traps the antiatoms in a magnetic minimum…

Detecting antihydrogen annihilations in ALPHA-g for measurement of gravitational free fall Antihydrogen, the bound state of an antiproton and a positron, is an ideal system for testing fundamental symmetries between matter and antimatter. The Antihydrogen Laser PHysics Apparatus (ALPHA) at CERN has a proven history of producing and trapping antihydrogen atoms, with many precision tests…

Machine Learning Methods for Antihydrogen Detection Antihydrogen, composing an antiproton and positron, is the only bound state of two antiparticles yet to be synthesised, making for an enticing system to study the purported symmetry of matter and antimatter. As antihydrogen does not occur naturally in the observable universe, any study of this atom requires it…

First Measurement of Antihydrogen Free Fall Using a Radial Time Projection Chamber Using antihydrogen, an apparatus known as ALPHA-g was designed to test Einstein's Weak Equivalence Principle (WEP), where the acceleration due to gravity that a body experiences is independent of its structure or composition. A measurement of the gravitational mass of antimatter has never…

Magnetic Field Characterisation for Gravitational Free Fall Measurements of Antihydrogen in the ALPHA-g Experiment The bound state of an antiproton and positron, antihydrogen, is an ideal test particle for comparisons between matter and antimatter as hydrogen has been studied extensively through history both experimentally and theoretically. The Antihydrogen Laser Physics Apparatus (ALPHA) collaboration has made…

Exploiting Electron Magnetron Motion in a Penning-Malmberg Trap to Measure Patch Potentials, Misalignment, and Magnetic Fields. A sequence of electron clouds is extracted from an electron plasma reservoir. These clouds are highly reproducible and their E×B drift motion is nearly identical to that of a single particle, making them useful for measurements of electric and…

Laser-cooled Be+ for improved antihydrogen trapping and magnetometry We have laser cooled beryllium ions in a Penning-Malmberg trap dedicated for antihydrogen formation. This trap is combined with a magnetic minimum trap to confine antihydrogen.This can be used to assist in the studies of antihydrogen in two distinct ways. The first application of the cold 9Be+…

A proton source in the ALPHA apparatus for precision measurements of antihydrogen and hydrogen The apparent lack of antimatter within our local solar system, the Milky Way, and at Galactic boundaries is inconsistent with the Big Bang hypothesis. This disagreement has motivated many experiments to compare the properties and behaviour of antimatter and matter. The…

Measuring the Properties of Antihydrogen This thesis describes the latest results of the on-going efforts to measure the properties of antihydrogen within the ALPHA collaboration. More specifically, it covers the construction and commissioning of the ALPHA-g experiment [1], and the plans to measure how antimatter behaves in Earth’s gravitational field. A special emphasis is on…

On the Dynamics of Adiabatically Cooled Antihydrogen in an Octupole-Based Ioffe-Pritchard Magnetic Trap Antihydrogen is now routinely formed in ALPHA by combination of antiproton and positron plasmas. Formed anti-atoms with energy <∼0.5 K are trapped in an octupole- based Ioffe-Pritchard magnetic trap. Reducing trapped antihydrogen energy is expected to increase precision in experiments that measure…

Sympathetically Laser-Cooled Positron Plasmas for Antihydrogen Formation Answering the question of why we live in a matter-dominated universe is of great interest to contemporary physicists, as the Standard Model of Particle Physics predicts that matter and antimatter should only ever be produced in equal parts. Antihydrogen is a good candidate for searches for asymmetries between…

Optimization of Antiproton Capture and Delivery for the ALPHA Antihydrogen Experiment The ALPHA (Antihydrogen Laser PHysics Apparatus) collaboration at CERN is testing Charge-Parity-Time (CPT) symmetry through precise measurements with antihydrogen atoms and in the future will measure antihydrogen's free fall acceleration in Earth's gravitational field. The antihydrogen atoms are created by slowly merging cold plasmas…

Solid-state nuclear magnetic resonance magnetometry at low temperature with application to antimatter gravity experiments by ALPHA The Einstein Equivalence Principle (EEP) has never been directly examined with an antimatter test body. To address this, ALPHA is planning to measure the Earth’s gravitational field using antihydrogen atoms as test masses. The experiment calls for the careful…

Design and Commissioning of Beamlines for the ALPHA Antihydrogen Experiment One of the greatest problems facing modern physics is the apparent asymmetry between matter and antimatter. While the standard model of particle physics predicts that equal amounts of matter and antimatter were produced following the Big Bang, astronomical observations have revealed that our universe contains…

Cavity and Microwave Experiments on Electron Plasma A new technique for rapidly generating a sequence of target plasmas in a Penning-Malmberg trap is presented and applied in the first demonstration of cavity-resonant cooling in a plasma. This "reservoir'' technique further enables the in situ magnetic field to be measured to high precision by microwave ECR…

Methods for plasma stabilization and control to improve antihydrogen production The ALPHA (Antihydrogen Laser Physics Apparatus) collaboration creates and performs precise measurements on antihydrogen to test Charge-Parity-Time (CPT) symmetry. Prior to creating antihydrogen we must prepare the antiproton and positron plasmas to have optimal and repeatable parameters. This thesis presents the development of a new…

Observation Of The 1S-2S Transition In Trapped Antihydrogen Our current understanding of physics suggests that matter and antimatter should be created and destroyed in equal amounts, but this seems inconsistent with the observation that our universe consists almost entirely of matter. Comparisons between matter and antimatter could reveal new physics which explains why the universe…

Laser-Ablated Beryllium Ions For Cold Antihydrogen In ALPHA One of the best ways to study antimatter is to investigate antihydrogen, the bound state of an antiproton and a positron. Antihydrogen atoms do not exist naturally and must be synthesized in the lab by merging carefully-prepared plasmas of positrons and antiprotons. If the atoms are created…

Tests Of Fundamental Symmetries With Trapped Antihydrogen Antihydrogen is the simplest pure antimatter atomic system, and it allows for direct tests of CPT symmetry as well as the weak equivalence principle. Furthermore, the study of antihydrogen may provide clues to the matter- antimatter asymmetry observed in the universe – one of the major unanswered questions…

Cold Antihydrogen Experiments And Radial Compression Of Antiproton Clouds In The ALPHA Apparatus At CERN Antihydrogen is the simplest neutral antimatter atom. Precision comparisons between hydrogen and antihydrogen would provide stringent tests of CPT (charge conjugation/parity transformation/time reversal) invariance and the weak equivalence principle. In the last few years, the ALPHA collaboration has produced, and…

Testing CPT and antigravity with trapped antihydrogen at ALPHA High precision antihydrogen experiments allow tests of fundamental theoretical descriptions of nature. These experiments are performed with the ALPHA apparatus, where ultra-low energy antihydrogen is produced and confined in a magnetic trap. Antihydrogen spectroscopy is of primary interest for precision tests of CPT invariance – one…

Antiproton And Positron Dynamics In Antihydrogen Production The asymmetry between matter and antimatter in the universe and the incompatibility between the Standard Model and general relativity are some of the greatest unsolved questions in physics. The answer to both may possibly lie with the physics beyond the Standard Model, and comparing the properties of hydrogen…

Studies On The Neutrality Of Antihydrogen The recent demonstration of trapping of antihydrogen atoms by the ALPHA collaboration at CERN opened great possibilities to study antimatter and perform precision measurements on it. In this work, a retrospective analysis of the 2010 and 2011 experimental runs in ALPHA, together with comprehensive studies of the apparatus and…

Microwave Spectroscopy Of Magnetically Trapped Atomic Antihydrogen We have every reason to believe that equal amounts of matter and antimatter were produced in the early universe. Moreover, theory predicts that the laws of physics make no distinction between the two. In this light, the fact that the observable universe is overwhelmingly dominated by matter is…

Probing Trapped Antihydrogen: In Situ Diagnostics And Observations Of Quantum Transitions Antihydrogen, the bound state of a positron and an antiproton, is the simplest pure anti-atomic system and an excellent candidate to test the symmetry between matter and antimatter. This thesis focuses on the magnetic confinement of antihydrogen and the first ever resonant interaction with…

Detection Of Trapped Antihydrogen The ALPHA experiment is an international effort to produce, trap, and perform precision spectroscopic measurements on antihydrogen (the bound state of a positron and an antiproton). Based at the Antiproton Decelerator (AD) facility at CERN, the ALPHA experiment has recently magnetically confined antihydrogen atoms for the first time. A crucial element…

The Effect Of Multipole-Enhanced Diffusion On The Joule Heating Of A Cold Non-Neutral Plasma One proposed technique for trapping anti-atoms is to superimpose a Ioffe-Pritchard style magnetic-minimum neutral trap on a standard Penning trap used to trap the charged atomic constituents. Adding a magnetic multipole field in this way removes the azimuthal symmetry of the…

Antihydrogen Formation, Dynamics And Trapping Antihydrogen, the simplest pure-antimatter atomic system, holds the promise of direct tests of matter-antimatter equivalence and CPT invariance, two of the outstanding unanswered questions in modern physics. Antihydrogen is now routinely produced in charged-particle traps through the combination of plasmas of antiprotons and positrons, but the atoms escape and are…

Evaporative Cooling Of Antiprotons And Efforts To Trap Antihydrogen Evaporative cooling has proven to be an invaluable technique in atomic physics, allowing for the study of effects such as Bose-Einstein condensation. One main topic of this thesis is the first application of evaporative cooling to cold non-neutral plasmas stored in an ion trap. We (the…

Development Of An Antihydrogen Trapping Apparatus This thesis details the development and commissioning of the ALPHA antihydrogen trapping apparatus. It discusses the history of antimatter physics that led to and enabled the design of the apparatus. It discusses the importance of antihydrogen trapping in testing one of the basic assumptions of the Standard Model of…

Modelling Of Antihydrogen Formation And The Commissioning Of The ALPHA Antihydrogen Apparatus This thesis describes several models of antihydrogen formation as well as the commissioning of the ALPHA antihydrogen during the 2006 Antiproton Decelerator (AD) physics run. Three models are given to describe the short-time production of antihydrogen, including the Simple Temperature Dependant Model, Inverse…