Download or read book Studies of Ion Acceleration from Thin Solid density Targets on High intensity Lasers written by Christopher R. Willis and published by . This book was released on 2016 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past two decades, a number of experiments have been performed demonstrating the acceleration of ions from the interaction of an intense laser pulse with a thin, solid density target. These ions are accelerated by quasi-static electric fields generated by energetic electrons produced at the front of the target, resulting in ion energies up to tens of MeV. These ions have been widely studied for a variety of potential applications ranging from treatment of cancer to the production of neutrons for advanced radiography techniques. However, realization of these applications will require further optimization of the maximum energy, spectrum, or species of the accelerated ions, which has been a primary focus of research to date. This thesis presents two experiments designed to optimize several characteristics of the accelerated ion beam. The first of these experiments took place on the GHOST laser system at the University of Texas at Austin, and was designed to demonstrate reliable acceleration of deuterium ions, as needed for the most efficient methods of neutron generation from accelerated ions. This experiment leveraged cryogenically cooled targets coated in D2O ice to suppress the protons which typically dominate the accelerated ions, producing as many as 2 x 10^10 deuterium ions per 1 J laser shot, exceeding the proton yield by an average ratio of 5:1. The second major experiment in this work was performed on the Scarlet laser system at The Ohio State University, and studied the accelerated ion energy, yield, and spatial distribution as a function of the target thickness. In principle, the peak energy increases with decreasing target thickness, with the thinnest targets accessing additional acceleration mechanisms which provide favorable scaling with the laser intensity. However, laser prepulse characteristics provide a lower bound for the target thickness, yielding an optimum target thickness for ion acceleration which is dependent on the laser system. This experiment utilized new liquid crystal film targets developed at OSU, which may be formed at variable thicknesses from tens of nanometers to several microns. On this experiment, an optimum ion energy and flux was reached for targets of 600-900 nm, providing a peak proton energy of 24 MeV, and total ion flux of >10^9 protons over 3.4 MeV from 5.5 J of laser energy at an intensity of 1 x 10^20 W/cm^2. The primary ion diagnostics for these two experiments are described in detail, including the analysis techniques needed to extract absolutely calibrated spatial and spectral distributions of the accelerated ions. Additionally, a new technique for target alignment is presented, providing repeatable target alignment on the micron scale. This allows for a repeatable laser intensity on target, allowing improved shot to shot consistency on high intensity experiments. In addition to these two experiments, work on the upgrade and characterization of the 400 TW Scarlet laser is discussed, including several calculations critical to the design and upgrade of the laser system, as well as prepulse characterization needed for experiments on thin targets.
Download or read book Novel High energy Physics Studies Using Intense Lasers and Plasmas written by and published by . This book was released on 2015 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the framework of the project "Novel high-energy physics studies using intense lasers and plasmas" we conducted the study of ion acceleration and "flying mirrors" with high intensity lasers in order to develop sources of ion beams and high frequency radiation for different applications. Since some schemes of laser ion acceleration are also considered a good source of "flying mirrors", we proposed to investigate the mechanisms of "mirror" formation. As a result we were able to study the laser ion acceleration from thin foils and near critical density targets. We identified several fundamental factors limiting the acceleration in the RPA regime and proposed the target design to compensate these limitations. In the case of near critical density targets, we developed a concept for the laser driven ion source for the hadron therapy. Also we studied the mechanism of "flying mirror" generation during the intense laser interaction with thin solid density targets. As for the laser-based positron creation and capture we initially proposed to study different regimes of positron beam generation and positron beam cooling. Since the for some of these schemes a good quality electron beam is required, we studied the generation of ultra-low emittance electron beams. In order to understand the fundamental physics of high energy electron beam interaction with high intensity laser pulses, which may affect the efficient generation of positron beams, we studied the radiation reaction effects.
Download or read book Progress in Ultrafast Intense Laser Science VII written by Kaoru Yamanouchi and published by Springer Science & Business Media. This book was released on 2011-05-07 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science, which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed chapters authored by researchers at the forefront of each their own subfields of UILS. Every chapter begins with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance and attractions of the research topic at hand; these are followed by reports of cutting-edge discoveries. This seventh volume covers a broad range of topics from this interdisciplinary research field, focusing on the ionization of atoms and molecules, ultrafast responses of protons and electrons within a molecule, molecular alignment, high-order harmonics and attosecond pulse generation, and acceleration of electrons and ions in laser plasmas.
Download or read book Theoretical and Numerical Study of the Laser plasma Ion Acceleration written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The laser driven ion acceleration is a burgeoning field of resarch and is attracting a growing number of scientists since the first results reported in 2000 obtained irradiating thin solid foils by high power laser pulses. The growing interest is driven by the peculiar characteristics of the produced bunches, the compactness of the whole accelerating system and the very short accelerating length of this all-optical accelerators. A fervent theoretical and experimental work has been done since then. An important part of the theoretical study is done by means of numerical simulations and the most widely used technique exploits PIC codes ("Particle In Cell'"). In this thesis the PIC code AlaDyn, developed by our research group considering innovative algorithms, is described. My work has been devoted to the developement of the code and the investigation of the laser driven ion acceleration for different target configurations. Two target configurations for the proton acceleration are presented together with the results of the 2D and 3D numerical investigation. One target configuration consists of a solid foil with a low density layer attached on the irradiated side. The nearly critical plasma of the foam layer allows a very high energy absorption by the target and an increase of the proton energy up to a factor 3, when compared to the ``pure'' TNSA configuration. The differences of the regime with respect to the standard TNSA are described The case of nearly critical density targets has been investigated with 3D simulations. In this case the laser travels throughout the plasma and exits on the rear side. During the propagation, the laser drills a channel and induce a magnetic vortex that expanding on the rear side of the targer is source of a very intense electric field. The protons of the plasma are strongly accelerated up to energies of 100 MeV using a 200PW laser.
Download or read book Ion Acceleration from the Interaction of Ultra Intense Lasers with Solid Foils written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The discovery that ultra-intense laser pulses (I> 10[sup 18] W/cm[sup 2]) can produce short pulse, high energy proton beams has renewed interest in the fundamental mechanisms that govern particle acceleration from laser-solid interactions. Experiments have shown that protons present as hydrocarbon contaminants on laser targets can be accelerated up to energies> 50 MeV. Different theoretical models that explain the observed results have been proposed. One model describes a front-surface acceleration mechanism based on the ponderomotive potential of the laser pulse. At high intensities (I> 10[sup 18] W/cm[sup 2]), the quiver energy of an electron oscillating in the electric field of the laser pulse exceeds the electron rest mass, requiring the consideration of relativistic effects. The relativistically correct ponderomotive potential is given by U[sub p] = ([1 + I[lambda][sup 2]/1.3 x 10[sup 18]][sup 1/2] - 1) m[sub o]c[sup 2], where I[lambda][sup 2] is the irradiance in W [micro]m[sup 2]/cm[sup 2] and m[sub o]c[sup 2] is the electron rest mass. At laser irradiance of I[lambda][sup 2] [approx] 10[sup 20] W [micro]m[sup 2]/cm[sup 2], the ponderomotive potential can be of order several MeV. A few recent experiments--discussed in Chapter 3 of this thesis--consider this ponderomotive potential sufficiently strong to accelerate protons from the front surface of the target to energies up to tens of MeV. Another model, known as Target Normal Sheath Acceleration (TNSA), describes the mechanism as an electrostatic sheath on the back surface of the laser target. According to the TNSA model, relativistic hot electrons created at the laser-solid interaction penetrate the foil where a few escape to infinity. The remaining hot electrons are retained by the target potential and establish an electrostatic sheath on the back surface of the target. In this thesis we present several experiments that study the accelerated ions by affecting the contamination layer from which they originate. Radiative heating was employed as a method of removing contamination from palladium targets doped with deuterium. We present evidence that ions heavier than protons can be accelerated if hydrogenous contaminants that cover the laser target can be removed. We show that deuterons can be accelerated from the deuterated-palladium target, which has been radiatively heated to remove contaminants. Impinging a deuteron beam onto a tritiated-titanium catcher could lead to the development of a table-top source of short-pulse, 14-MeV fusion neutrons. We also show that by using an argon-ion sputter gun, contaminants from one side of the laser target can be selectively removed without affecting the other side. We show that irradiating a thin metallic foil with an ultra-intense laser pulse produces a proton beam with a yield of 1.5-2.5 10[sup 11] and temperature, kT = 1.5 MeV with a maximum proton energy> 9 MeV. Removing contaminants from the front surface of the laser target with an argon-ion sputter gun, had no observable effect on the proton beam. However, removing contaminants from the back surface of the laser target reduced the proton beam by two orders of magnitude to, at most, a yield of [approx] 10[sup 9] and a maximum proton energy 4 MeV. Based on these observations, we conclude that the majority ( 99%) of high energy protons (E> 5 MeV) from the interaction of an ultra-intense laser pulse with a thin foil originate on the back surface of the foil--as predicted by the TNSA model. Our experimental results are in agreement with PIC simulations showing back surface protons reach energies up to 13 MeV, while front surface protons reach a maximum energy of 4 MeV. Well diagnosed and controllable proton beams will have many applications: neutron radiography, material damage studies, production of medical isotopes, and as a high-resolution radiography tool for diagnosing opaque materials and plasmas. Well collimated and focusable ion beams may also prove beneficial for alternative inertial-fusion concepts such as proton fast ignition, a potentially viable method for achieving a controlled fusion reaction in the laboratory earlier than expected.
Download or read book Progress in Ultrafast Intense Laser Science II written by See Leang Chin and published by Springer Science & Business Media. This book was released on 2007-06-10 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book series addresses a newly emerging interdisciplinary research field, Ultrafast Intense Laser Science, spanning atomic and molecular physics, molecular science, and optical science. Highlights of this second volume include Coulomb explosion and fragmentation of molecules, control of chemical dynamics, high-order harmonic generation, propagation and filamentation, and laser-plasma interaction. All chapters are authored by foremost experts in their fields.
Download or read book Frontiers in High Energy Density Physics written by National Research Council and published by National Academies Press. This book was released on 2003-05-11 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent scientific and technical advances have made it possible to create matter in the laboratory under conditions relevant to astrophysical systems such as supernovae and black holes. These advances will also benefit inertial confinement fusion research and the nation's nuclear weapon's program. The report describes the major research facilities on which such high energy density conditions can be achieved and lists a number of key scientific questions about high energy density physics that can be addressed by this research. Several recommendations are presented that would facilitate the development of a comprehensive strategy for realizing these research opportunities.
Download or read book Laser Pulses written by Igor Peshko and published by BoD – Books on Demand. This book was released on 2012-10-17 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses aspects of laser pulses generation, characterization, and practical applications. Some new achievements in theory, experiments, and design are demonstrated. The introductive chapter shortly overviews the physical principles of pulsed lasers operation with pulse durations from seconds to yoctoseconds. A theory of mode-locking, based on the optical noise concept, is discussed. With this approximation, all paradoxes of ultrashort laser pulse formation have been explained. The book includes examples of very delicate laser operation in biomedical areas and extremely high power systems used for material processing and water purification. We hope this book will be useful for engineers and managers, for professors and students, and for those who are interested in laser science and technologies.
Download or read book Reviews Of Accelerator Science And Technology Volume 9 Technology And Applications Of Advanced Accelerator Concepts written by Alexander Wu Chao and published by World Scientific. This book was released on 2017-02-20 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its invention in the 1920s, particle accelerators have made tremendous progress in accelerator science, technology and applications. However, the fundamental acceleration principle, namely, to apply an external radiofrequency (RF) electric field to accelerate charged particles, remains unchanged. As this method (either room temperature RF or superconducting RF) is approaching its intrinsic limitation in acceleration gradient (measured in MeV/m), it becomes apparent that new methods with much higher acceleration gradient (measured in GeV/m) must be found for future very high energy accelerators as well as future compact (table-top or room-size) accelerators. This volume introduces a number of advanced accelerator concepts (AAC) — their principles, technologies and potential applications. For the time being, none of them stands out as a definitive direction in which to go. But these novel ideas are in hot pursuit and look promising. Furthermore, some AAC requires a high power laser system. This has the implication of bringing two different communities — accelerator and laser — to join forces and work together. It will have profound impact on the future of our field.Also included are two special articles, one on 'Particle Accelerators in China' which gives a comprehensive overview of the rapidly growing accelerator community in China. The other features the person-of-the-issue who was well-known nuclear physicist Jerome Lewis Duggan, a pioneer and founder of a huge community of industrial and medical accelerators in the US.
Download or read book Reviews of Accelerator Science and Technology Volume 2 Medical Applications of Accelerators written by Alexander W. Chao and published by World Scientific. This book was released on 2009-12-01 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: The theme of this volume, ?Medical Applications of Accelerators?, is of enormous importance to human health and has a deep impact on our society.The invention of particle accelerators in the early 20th century created a whole new world for producing energetic X-rays, electrons, protons, neutrons and other particle beams. Immediately these beams found revolutionary applications in medicine. There are two important yet distinct medical applications. On the one hand, accelerators produce radioisotopes for various nuclear medicines for millions of patients each year, and on the other hand, they also produce particle beams for radiation therapy for the treatment of cancer. The particle beams can be X-rays (generated by high-energy electrons), protons, neutrons or heavy ions such as carbon. Today there are more than 5,000 accelerators routinely used in hospitals all over the world for nuclear medicine and cancer therapy. The great potential of accelerator applications in medicine can hardly be exaggerated.This volume contains 14 articles, all written by distinguished scholars.
Download or read book Reviews Of Accelerator Science And Technology Volume 2 Medical Applications Of Accelerators written by Alexander Wu Chao and published by World Scientific. This book was released on 2009-12-30 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: The theme of this volume, “Medical Applications of Accelerators”, is of enormous importance to human health and has a deep impact on our society.The invention of particle accelerators in the early 20th century created a whole new world for producing energetic X-rays, electrons, protons, neutrons and other particle beams. Immediately these beams found revolutionary applications in medicine. There are two important yet distinct medical applications. One is that accelerators produce radioisotopes for various nuclear medicines for millions of patients each year. The other is that accelerators produce particle beams for radiation therapy for the treatment of cancer. The particle beams can be X-rays (generated by high-energy electrons), protons, neutrons or heavy ions such as carbon. Today there are more than 5,000 accelerators routinely used in hospitals all over the world for nuclear medicine and cancer therapy. The great potential of accelerator applications in medicine can hardly be exaggerated.This volume contains 14 articles, all written by distinguished scholars.
Download or read book Proceedings of the Tenth International Symposium on Applied Electromagnetic and Mechanics written by T. Takagi and published by IOS Press. This book was released on 2003 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication covers topics in the area of applied electromagnetics and mechanics. Since starting in Japan in 1988, the ISEM has become a well-known international forum on applied electromagnetics.
Download or read book Ion acceleration and extreme light field generation based on ultra short and ultra intense lasers written by Liangliang Ji and published by Springer Science & Business Media. This book was released on 2014-01-23 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is dedicated to the relativistic (laser intensity above 1018 W/cm2) laser-plasma interactions, which mainly concerns two important aspects: ion acceleration and extreme-light-field (ELF). Based on the ultra-intense and ultra–short CP lasers, this book proposes a new method that significantly improves the efficiency of heavy-ion acceleration, and deals with the critical thickness issues of light pressure acceleration. More importantly, a series of plasma approaches for producing ELFs, such as the relativistic single-cycle laser pulse, the intense broad-spectrum chirped laser pulse and the ultra-intense isolated attosecond (10-18s) pulse are introduced. This book illustrates that plasma not only affords a tremendous accelerating gradient for ion acceleration but also serves as a novel medium for ELF generation, and hence has the potential of plasma-based optics, which have a great advantage on the light intensity due to the absence of device damage threshold.
Download or read book High Field Plasmonics written by Luca Fedeli and published by Springer. This book was released on 2016-09-26 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes pioneering research on the extension of plasmonics schemes to the regime of high-intensity lasers. By presenting a rich and balanced mix of experimentation, theory and simulation, it provides a comprehensive overview of the emerging field of high field plasmonics, including open issues and perspectives for future research. Combining specially designed targets and innovative materials with ultrashort, high-contrast laser pulses, the author experimentally demonstrates the effects of plasmon excitation on electron and ion emission. Lastly, the work investigates possible further developments with the help of numerical simulations, revealing the potential of plasmonics effects in the relativistic regime for advances in laser-driven sources of radiation, and for the manipulation of extreme light at the sub-micron scale.
Download or read book New Photon Science and Extreme Field Physics written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The constantly improving capabilities of ultra-high power lasers are enabling interactions of matter with ever extremer fields. As both the on target intensity and the laser contrast are increasing, new physics regimes are becoming accessible and new effects materialize, which in turn enable a host of applications. A first example is the realization of interactions in the transparent-overdense regime (TOR), which is reached by interacting a highly relativistic (a0> 10), ultra high contrast laser pulse with a solid density, nanometer target. Here, a still overdense target is turned transparent to the laser by the relativistic mass increase of the electrons, increasing the skin depth beyond the target thickness and thus enabling volumetric interaction of the laser with the entire target instead of only a small interaction region at the critical density surface. This increases the energy coupling, enabling a range of effects, including relativistic optics and pulse shaping, mono-energetic electron acceleration, highly efficient ion acceleration in the break-out afterburner regime, the generation of relativistic and forward directed surface harmonics. In this talk we will show the theoretical framework for this regime, explored by multi-D, high resolution and high density PIC simulations as well as analytic theory and present measurements and experimental demonstrations of direct relativistic optics, relativistic HHG, electron acceleration, and BOA ion acceleration in the transparent overdense regime. These effects can in turn be used in a host of applications including laser pulse shaping, ICF diagnostics, coherent x-ray sources, and ion sources for fast ignition (IFI), homeland security applications and medical therapy. This host of applications already makes transparent-overdense regime one of general interest, a situation reinforced by the fact that the TOR target undergoes an extremely wide HEDP parameter space during interaction ranging from WDM conditions (e.g . brown dwarfs) early in the interaction to extremely high energy densities of H"011 J/cm3 at peak, dropping back to the underdense but extremely hot parameter range of gamma-ray bursts. Furthermore, whereas today this regime can only be accessed on very few dedicated facilities, employing special targets and pulse cleaning technology, the next generation of laser facilities like RAL-10PW, ELI, or Gekko-Exa will operate in this regime by default, turning its understanding in a necessity rather than a curiosity.
Download or read book Optimizing Laser ion Acceleration with Flat and Structured Foils written by Joseph Strehlow and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability of relativistic laser pulses to accelerate ions from foil targets has long been established. These beams, with their high current density and ultrashort duration, are essential tools in high energy density science and have great promise as an upcoming technology in accelerator physics. To best fulfill their applications, the conversion efficiency of laser to ion energy must be optimized, with the ultimate goal of tunable ion energy, yield, and other beam parameters. The acceleration of both light and heavy ions is of interest, as they each have different uses, such as neutron generation and rare isotope production. Two experiments were carried out at the Texas Petawatt laser facility. The first experiment studied the response of imaging plate detectors to heavy ions, expanding the published literature beyond light ion calibrations. Successful modeling of the imaging plate's response function is essential to determining the absolute number of ions accelerated. A comparison of all published calibrations produces an empirical estimate for ion response for any arbitrary ion as a function of atomic mass. The second experiment investigated ion acceleration from 3D printed targets, whose protruding structure increases laser-target coupling. These structures were of the "microtube" geometry, and are most effective under the right conditions of laser intensity, pulse duration, and energy. These results are then compared to experiments on similar target structures at the PHELIX and ALEPH laser facilities, which also showed enhanced ion production. A numerical study on heavy ion acceleration was also conducted, in an optimization of the generation of multiply charged titanium beams. A thickness scan on submicron targets was executed for two laser pulse lengths to determine the best performing target for each laser. In the relativistically induced transparency regime, we show that collisional ionization cannot be neglected for sufficiently long laser pulses (near picosecond). Identifying this threshold is crucial for balancing the conservation of computational resources with accurate particle-in-cell modeling. This large body of experimental and numerical data continue to support the tremendous progress in short pulse laser-ion acceleration over the course of three decades. Continuing to push the bounds in conversion efficiency and beam control is essential for breaking ground in high energy density physics and accelerator development.
Download or read book Short Pulse Laser Interactions With Matter An Introduction written by Paul Gibbon and published by World Scientific. This book was released on 2005-09-05 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book represents the first comprehensive treatment of the subject, covering the theoretical principles, present experimental status and important applications of short-pulse laser-matter interactions.Femtosecond lasers have undergone dramatic technological advances over the last fifteen years, generating a whole host of new research activities under the theme of “ultrafast science”. The focused light from these devices is so intense that ordinary matter is torn apart within a few laser cycles. This book takes a close-up look at the exotic physical phenomena which arise as a result of this new form of “light-matter” interaction, covering a diverse set of topics including multiphoton ionization, rapid heatwaves, fast particle generation and relativistic self-channeling. These processes are central to a number of exciting new applications in other fields, such as microholography, optical particle accelerators and photonuclear physics.Repository for numerical models described in Chapter 6 can be found at www.fz-juelich.de/zam/cams/plasma/SPLIM/./a
