We have performed a series of experiments developing the techniques of volumetric, isochoric heating of matter to high energy density states, and the subsequent probing of the release isentrope. Using ultrafast, ultra intense laser systems with pulse lengths from 100fs - 1ps and pulse energies between 2 J and 100 J, we generated strong secondary radiation, in the form of K[subscript alpha] x-rays and directed proton beams, which we used to rapidly heat a foil sample to temperatures from ~ 1 eV to ~ 25 eV at solid density, thus entering the strongly coupled, partially ionized regime of warm dense matter, in which the equation of state is poorly understood. The first set of experiments examines the possibility of using laser generated K[subscript alpha] x-rays in isochoric heating experiments and concludes that this technique will require the use of higher energies and higher Z materials than were used in this thesis to achieve warm dense matter conditions. In the second set of experiments, we used an ultrafast, lasergenerated proton beam with a temperature of ~ 2 MeV and cutoff energy of ~ 40 MeV to volumetrically and isochorically heat a sample foil to > 20 eV. With singleshot diagnostics, we measured the evolution of the temperature with 3:3 ps resolution over the _rst 35 ps of expansion by streaked optical pyrometry, and measured the evolution of the target expansion over the same timescale with sub-ps resolution by chirped pulse interferometry. In this way we were able to verify the equation of state and ion-balance in the SESAME equation of state tables with a Saha ionization model and distinguish this as more accurate than other, simpler models. This thesis establishes an experimental framework for acquiring equation of state data in the regime of warm dense matter that is distinct and complimentary to that acquired by the techniques of shock heating. / text

Since 2004, table-top laser-plasma accelerators (LPAs) driven by ˜30fs terwatt laser pulses have produced colimated, nearly mono-energetic eletron bunches with energy up to 1 GeV in laboratories around the world. Large-scale computer simulations show that LPAs can scale to higher energy while retaining high beam quality, but will require laser pulses of higher energy and longer duration than current LPAs. The group of Prof. Mike Downer, in collaboration with the Texas Petawatt (TPW) laser team headed by Prof. Todd Ditmire, is setting up an experiment that uses the TPW laser (1.1 PW, 150 fs) to drive the world’s first multi-GeV LPA. This thesis provides a general overview of the TPW-LPA project, including several diagnostic systems for the beam, plasma and laser pulse. Special attention is given to three of the diagnostic systems: (1)A transverse interferometry diagnostic of the plasma density profile created by the TPW laser pulse; (2)A Thomson scattering diagnostic of the self-guided path of the TPW laser pulse through the plasma; (3)An optical transition radiation diagnostic of the accelerated electron bunch exiting the plasma. In each case, basic principles, theoretical background, calculation and simulation results, and preliminary experimental results will be presented. / text

We study particle production and its density evolution and equilibration in hot dense medium, such as hadronic gas after quark gluon plasma hadronization and relativistic electron positron photon plasma. For this study we use kinetic momentum integrated equations for particles density evolution with Lorentz invariant reaction rates. We extend these equations, used before for two-to-two particles reactions (1 + 2 ↔ 3 + 4), to the case of two-to-one and backward reactions (1 + 2 ↔ 3). One type of hot dense medium, which we study, is hadronic gas produced at quark gluon plasma hadronization in heavy ions collisions in SPS, RHIC and LHC experiments. We study hadron production at quark gluon plasma hadronization and their evolution in thermal hadronic gas phase. We consider non-equilibrium hadronization model, for which the yields of the light quark hadrons are defined by entropy conservation. Yields of hadrons containing heavier (strange, charm, bottom) quarks are mainly controlled by flavor conservation. We predict yields of charm and bottom hadrons within this non-equilibrium statistical hadronization model. Then we use this non-equilibrium hadronization as the initial condition in the study of hadronic kinetic phase. During this time period some hadronic resonances can be produced in lighter hadrons fusion. This reaction is opposite to resonance decay. Production of resonances is dominant over decay if there is non-equilibrium excess of decay products. Within this model we explain apparently contradictory experimental results reported in RHIC experiments: ∑(1385) yield is enhanced while ∧(1520) yield is suppressed compared to the statistical hadronization model expectation obtained without kinetic phase. We also predict Δ(1232) enhancement. The second type of plasma medium we consider is the relativistic electron position photon plasma (EP³) drop. This plasma is expected to be produced in decay of supercritical field created in ultrashort laser pulse. We study at what conditions this plasma drop is opaque for photons and therefore may reach thermal and chemical equilibrium. Further we consider muon and pion production in this plasma also as a diagnostic tool. Such heavy particles can be diagnostic tool to study the properties of EP³ plasma, similar to the role taken by heavy hadrons production in heavy ions collisions. Finally all these theoretical developments can be applied to begin a study of particles evolution in early universe in temperatures domain from QGP hadronization (160 MeV) to nucleosynthesis (0.1 MeV). The first results on pion equilibration are presented here.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

This work deals with the study of dissociation of iodine molecule for Chemical and Discharge Oxygen-Iodine Laser. Chemical way of HI dissociation and discharge way of dissociation of CH3I and CF3I molecules is examined. Main diagnostics method is absorption spectroscopy. Part of the work is also the modeling of system of chemical reactions. Last part of this work is dealing with the study of plasma generated by the radiofrequency generator in the hollow cathode plasma jet system using argon or mixture of argon with iodine. Diagnostic method used is Langmuir probe.

L'interaction d'un laser ultra-intense et ultra-court avec la matière donne naissance à une grande variété de processus issus du couplage des ondes électromagnétiques associées au laser avec les modes du plasma. Ce couplage hautement non-linéaire excite des phénomènes plasmas collectifs capables de produire des champs intenses pouvant atteindre le TV/m. Ces champs ouvrent la possibilité de réaliser des accélérateurs de particules compacts, aussi bien d'électrons que d'ions. Des sources laser-plasma d'ions de plusieurs dizaines de MeV ont été démontré au début des années 2000 et de nombreux mécanismes ont été suggérés depuis afin d'en améliorer les propriétés. Historiquement, les sources d'ions par laser ont été obtenues à partir de cibles solides dîtes sur-denses. L’innovation sur les cibles a été un moteur majeur de l’amélioration de ces sources. Dans la continuité de cette dynamique, l’utilisation de cibles gazeuses a été proposé afin d’alléger les contraintes de contraste laser et de taux de répétition. De récentes démonstrations expérimentales sont venus renforcer l’intérêt pour ces cibles, dîtes sous-denses ou proche critiques, dont la valeur est propice à la propagation, à l’absorption du laser et à la création de structures accélératrices que sont les chocs plasmas et les vortex magnétiques. Les travaux présentés dans cette thèse constituent une exploration expérimentale des paramètres plasmas nécessaires à l’accélération d’ions dans des cibles gazeuses de densité proche-critique. Pour la première fois ces régimes sont explorés avec un laser ultra-intense femtoseconde de 150TW. Une partie des travaux a été consacrée à la réalisation d’une cible innovante, adaptée aux contraintes de densité et de gradients plasma requises par ces régimes. Suivent, les travaux expérimentaux décrivant la propagation du laser et l’accélération d’électrons dans des cibles proche-critiques. Enfin une dernière partie décrit la production d’un faisceau d’atome issue d’une source d’ion laser. / Interaction of ultra-intense, ultra-short laser with matter gives rise to a wealth of phenomena, due to the coupling between the electromagnetic field and the plasma. The non-linear coupling excites collective plasma processes able to sustain intense electric fields up to 1TV/m. This property spurred early interest in laser accelerator as compact, next-generation source of accelerated electrons and ions. Laser-driven ion source of several MeV was demonstrated in early 2000 an various mechanisms had been suggest to improve the their properties. These first ion sources have been obtained on solid targets, called “overdense”. Target innovation has driven the improvement of these sources. In the continuity of this dynamic, new gaseous targets had been proposed in order to relax the constraints that solid targets impose on laser contrast and repetition rate. Recent experimental demonstrations of monoenergetic ion acceleration in gas renew the interest in such targets, called under-dense or near-critical because of their intermediate densities. At near-critical density the laser can propagate, but undergoes significant absorbtion, giving rise to the accelerating structures of plasma shocks and magnetic vortex.The work presented in this thesis is an experimental exploration of the plasma conditions required to drive ion acceleration in gaseous near-critical target. For the first time, these regimes are explored with an ultra-intense, femtosecond laser of 150TW. A part of this work has been dedicated to the design of an innovative gas target, suited for plasma density and gradient constraints set by these regimes. Then the experimental works describe laser propagation and electron acceleration in near-critical targets. Finally the last part report the efficient production of an atomic beam from a laser-driven ion source.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18998号 / 工博第4040号 / 新制||工||1622(附属図書館) / 31949 / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 作花 哲夫, 教授 安部 武志, 教授 田中 勝久 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第20018号 / エネ博第341号 / 新制||エネ||68(附属図書館) / 33114 / 京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻 / (主査)教授 岸本 泰明, 教授 中村 祐司, 准教授 田中 仁 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

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