Generation of GeV protons from 1 PW laser interaction with near critical density targets

The propagation of ultra intense laser pulses through matter is connected with the generation of strong moving magnetic fields in the propagation channel as well as the formation of a thin ion filament along the axis of the channel. Upon exiting the plasma the magnetic field displaces the electrons at the back of the target, generating a quasistatic electric field that accelerates and collimates ions from the filament. Two-dimensional Particle-in-Cell simulations show that a 1 PW laser pulse tightly focused on a near-critical density target is able to accelerate protons up to an energy of 1.3 GeV. Scaling laws and optimal conditions for proton acceleration are established considering the energy depletion of the laser pulse.Comment: 26 pages, 8 figure

ПРИМЕНЕНИЕ ВНУТРЕННЕГО СТАНДАРТА ПРИ ИЗОТОПНОМ АНАЛИЗЕ ВЫСОКООБОГАЩЕННОГО “КРЕМНИЯ-28” МЕТОДОМ МАСС-СПЕКТРОМЕТРИИ ВЫСОКОГО РАЗРЕШЕНИЯ С ИНДУКТИВНО СВЯЗАННОЙ ПЛАЗМОЙ

 In order to study the isotopic effects in semiconductor materials, single crystals of high chemical and isotopic purity are required. The reliability of the obtained data on the magnitude and the direction of isotopic shifts depends on the accuracy of determining the concentration of all stable isotopes. In the isotopic analysis of enriched “silicon-28” with a high degree of enrichment ( 99.99%), it is necessary to determine the impurities of 29Si and 30Si isotopes at the level of 10-3 ¸ 10-5 at. %. At this concentration level, these isotopes can be considered as impurities. It is difficult to achieve high measurement accuracy with simultaneous registration of the main and “impurity” isotopes in such a wide range of concentrations. The registration of analytical signals of silicon isotopes must be carried out in the solutions with different matrix concentrations. The use of the solutions with the high concentration of the matrix element requires the introduction of corrections for matrix noise and the drift of the instrument sensitivity during the measurement. It is possible to reduce the influence of the irreversible non-spectral interference and sensitivity drift by using the method of internal standardization. The inconsistency of the literature data on the selection criteria for the internal standard required studying the behavior of the signals of the “candidates for the internal standard” for the ELEMENT 2 single-collector high-resolution inductively coupled plasma mass spectrometer on the matrix element concentration and the nature of the solvent, as well as on the solution nebulizing time. Accounting for the irreversible non-spectral matrix noise and instrumental drift in isotopic analysis of enriched “silicon-28” and initial 28SiF4 by inductively coupled plasma mass spectrometry had allowed us to reduce by 3-5 times the random component and by more than an order of magnitude the systematic component of the measurement error in comparison with the external standard method. This made it possible to carry out, with sufficient accuracy, the operational control of the isotopic composition of enriched “silicon-28”, both in the form of silicon tetrafluoride and polycrystalline silicon obtained from it, using a single serial device in the range of isotopic concentrations 0.0001–99.999%.Key words: high-resolution inductively coupled plasma mass spectrometry, isotope analysis, isotopically enriched silicon, internal standard DOI: http://dx.doi.org/10.15826/analitika.2021.25.2.009P.A. Otopkova, A.M. Potapov, A.I. Suchkov, A.D. Bulanov, A.Yu. Lashkov G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences (IChHPS RAS), 49 Tropinina St., Nizhny Novgorod, 603951, Russian FederationДля изучения изотопических эффектов в полупроводниковых материалах требуются монокристаллы с высокой химической и изотопной чистотой. Надежность полученных данных о величине и направлении изотопических сдвигов зависит от точности определения концентрации всех стабильных изотопов. При изотопном анализе обогащенного “кремния-28” с высокой степенью обогащения (более 99.99 %) необходимо определять примеси изотопов 29Si и 30Si на уровне 10-3 ¸ 10-5 ат. %. На таком уровне концентраций указанные изотопы можно рассматривать как примеси. Достижение высокой точности измерений при одновременной регистрации основного и “примесных” изотопов в таком широком интервале концентраций затруднительно. Регистрацию аналитических сигналов изотопов кремния приходится проводить на растворах с разной концентрацией матрицы. Использование растворов с высокой концентрацией матричного элемента требует введения поправок на матричные помехи и дрейф чувствительности прибора в процессе измерения. Снизить влияние необратимых неспектральных помех и дрейфа чувствительности можно при использовании метода внутренней стандартизации. Противоречивость литературных данных о критериях выбора внутреннего стандарта потребовала исследования поведения сигналов элементов “кандидатов во внутренний стандарт“ для одноколлекторного масс-спектрометра высокого разрешения с индуктивно связанной плазмой ELEMENT 2 от концентрации матричного элемента и природы растворителя, а также от времени распыления раствора. Учет необратимых неспектральных матричных помех и аппаратного дрейфа при изотопном анализе обогащенного “кремния-28” и исходного 28SiF4 методом масс-спектрометрии с индуктивно связанной плазмой позволил снизить в 3-5 раз случайную составляющую и более чем на порядок систематическую составляющую погрешности измерения по сравнению с методом внешнего стандарта. Это позволило проводить с достаточной точностью оперативный контроль изотопного состава обогащенного “кремния-28”, как в виде тетрафторида кремния, так и получаемого из него поликристаллического кремния с помощью одного серийного прибора в интервале изотопных концентраций 0.0001–99.999 ат. %.Ключевые слова: масс-спектрометрия высокого разрешения с индуктивно связанной плазмой, изотопный анализ, изотопнообогащенный кремний, внутренний стандартDOI: http://dx.doi.org/10.15826/analitika.2021.25.2.00

ЭЛЕМЕНТНЫЙ АНАЛИЗ ПЕНТАКАРБОНИЛА ЖЕЛЕЗА МЕТОДОМ МАСС-СПЕКТРОМЕТРИИ С ИНДУКТИВНО СВЯЗАННОЙ ПЛАЗМОЙ

A technique for the quantitative elemental analysis of iron pentacarbonyl by high-resolution mass spectrometry with inductively coupled plasma has been developed. Samples of Fe(CO)5 were transferred to a nitrate solution for the analysis. To account for the matrix noise and the drift of the sensitivity of the mass spectrometer during the analysis, three internal standards (9Be, 59Co, 181Ta) for the various mass ranges were used. The normalization of the measured intensities of analyte signals to the intensities of the corresponding internal standards made it possible to significantly improve the accuracy of determining the concentrations of impurities using the external calibration according to the pure standards. Using the developed technique, the concentrations of 28 elements’ impurities were determined. The behavior of impurities of elements forming their own carbonyl compounds in the process of fractional distillation of iron pentacarbonyl was studied. The analysis of iron pentacarbonyl fractions showed that the impurities of B, Ni and Ti were concentrated in the light fractions, and the impurities of Cr, Co, Cd, Mo and W in the heavy ones. The detection limits of iron in pentacarbonyl for widespread impurities such as Mg, Al, P, Cr, Ni were 10–6–10–5 wt. %, and for less common impurities of Bi, Cd, Co, Pt, Re, Tl, W, U - 10-8 ÷ 10-7 wt. % respectively.Keywords: iron pentacarbonyl, impurities determination, high resolution ICP-MS(Russian)DOI: http://dx.doi.org/10.15826/analitika.2019.23.1.014M.O. Steshin1, 2, A.M. Potapov1, A.D. Bulanov1, 2, Yu.S. Belozerov1, A.I. Suchkov11G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences (IChHPS RAS), 49 Tropinina St., Nizhny Novgorod, 603951, Russian Federation2National Research Lobachevsky State University of Nizhny Novgorod, pr. Gagarina 23, Nizhny Novgorod, 603950, Russian FederationРазработана методика количественного элементного анализа пентакарбонила железа методом масс-спектрометрии высокого разрешения с индуктивно связанной плазмой. Пробы Fe(CO)5 предварительно переводили в азотнокислый раствор. Для учета матричных помех и дрейфа чувствительности масс-спектрометра в процессе анализа в различных диапазонах масс применяли три внутренних стандарта (9Be, 59Co, 181Ta). Нормировка измеренных интенсивностей сигналов аналитов на интенсивности соответствующих внутренних стандартов позволила значительно повысить точность определения концентраций примесей при использовании внешней градуировки по чистым стандартам. С применением разработанной методики определено содержание примесей 29 элементов. Изучено поведение примесей элементов, образующих собственные карбонилы в процессе фракционной разгонки пентакарбонила железа. Анализ фракций пентакарбонила железа, показал, что примеси B, Ni и Ti концентрируются в легких фракциях, а примеси Cr, Co, Cd, Mo и W ‒ в тяжелых. Пределы обнаружения в пентакарбониле железа для распространенных примесей Mg, Al, P, Cr, Ni составили 10-6 ÷ 10-5 % мас., для нераспространенных примесей Bi, Cd, Co, Pt, Re, Tl, W, U ‒ 10-8 ÷ 10-7 % мас.Ключевые слова: пентакарбонил железа, элементный анализ, масс-спектрометрия с индуктивно связанной плазмой высокого разрешенияDOI: http://dx.doi.org/10.15826/analitika.2019.23.1.01

Nonlinear relativistic optics in the single cycle, single wavelength regime and kilohertz repetition rate

Pulses of few optical cycles, focused on one wavelength with relativistic intensities can be produced at a kilohertz repetition rate. By properly choosing the plasma and laser parameters, relativistic nonlinear effects, such as channeling and electron and ion acceleration to tens of megaelectronvolts are demonstrated. © 2002 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87926/2/138_1.pd

Control of proton energy in ultra-high intensity laser-matter interaction

Recent breakthroughs in short pulse laser technology resulted in (i) generation of ultra-high intensity (2×1022 W/cm2) and (ii) ultra-high contrast (10−11) short pulses at the Hercules facility of the University of Michigan, which has created the possibility of exploring a new regime of ion acceleration – the regime of Directed Coulomb Explosion (DCE). In this regime of sufficiently high laser intensities and target thicknesses approaching the relativistic plasma skin depth it is possible to expel electrons from the target focal volume by the laser's ponderomotive force allowing for direct laser ion acceleration combined with a Coulomb explosion. That results in greater than 100 MeV protons with a quasi-monoenergetic energy spectrum. The utilization of beam shaping, namely, the use of flat-top beams, leads to more efficient proton acceleration due to the increase of the longitudinal field. According to the results of 2D PIC simulations a 500 TW laser pulse with a super-Gaussian beam profile interacting with 0.1 micron aluminium-hydrogen foil is able to produce monoenergetic protons with the energy up to 240 MeV.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85403/1/jpconf10_244_042025.pd

Острая гемолитическая реакция после трансфузии эритроцитсодержащих компонентов крови: причины, профилактика, клинические случаи

The article concerns the problem of studying the causes of the development of hemolytic reactions after transfusion of erythrocyte-containing blood components. The ways of preventing hemolysis as a result of blood transfusions are considered. Clinical cases are described.Статья затрагивает проблему изучения причин развития гемолитических реакций после трансфузий эритроцитсодержащих компонентов крови. Рассмотрены пути предотвращения гемолиза в результате гемотрансфузий. Описаны клинические случаи

Energetic electron and ion generation from interactions of intense laser pulses with laser machined conical targets

The generation of energetic electron and proton beams was studied from the interaction of high intensity laser pulses with pre-drilled conical targets. These conical targets are laser machined onto flat targets using 7–180 µJ pulses whose axis of propagation is identical to that of the main high intensity pulse. This method significantly relaxes requirements for alignment of conical targets in systematic experimental investigations and also reduces the cost of target fabrication. These experiments showed that conical targets increase the electron beam charge by up to 44 ± 18% compared with flat targets. We also found greater electron beam divergence for conical targets than for flat targets, which was due to escaping electrons from the surface of the cone wall into the surrounding solid target region. In addition, the experiments showed similar maximum proton energies for both targets since the larger electron beam divergence balances the increase in electron beam charge for conical targets. 2D particle in cell simulations were consistent with the experimental results. Simulations for conical target without preplasma showed higher energy gain for heavy ions due to 'directed coulomb explosion'. This may be useful for medical applications or for ion beam fast ignition fusion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85411/1/nf10_5_055006.pd

On the design of experiments for the study of relativistic nonlinear optics in the limit of single-cycle pulse duration and single-wavelength spot size

We propose a set of experiments with the aim of studying for the first time relativistic nonlinear optics in the fundamental limits of single-cycle pulse duration and single-wavelength spot size. The laser system that makes this work possible is now operating at the Center for Ultrafast Optical Science at the University of Michigan. Its high repetition rate (1 kHz) will make it possible to perform a detailed investigation of relativistic effects in this novel regime. This study has the potential to make the field of relativistic optics accessible to a wider community and to open the door for real-world applications of relativistic optics, such as electron/ion acceleration and neutron and positron production.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45803/1/11452_2005_Article_253.pd

Controllable Laser Ion Acceleration

In this paper a future laser ion accelerator is discussed to make the laser-based ion accelerator compact and controllable. Especially a collimation device is focused in this paper. The future laser ion accelerator should have an ion source, ion collimators, ion beam bunchers, and ion post acceleration devices [Laser Therapy 22, 103(2013)]: the ion particle energy and the ion energy spectrum are controlled to meet requirements for a future compact laser ion accelerator for ion cancer therapy or for other purposes. The energy efficiency from the laser to ions is improved by using a solid target with a fine sub-wavelength structure or a near-critical density gas plasma. The ion beam collimation is performed by holes behind the solid target or a multi-layered solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching would be successfully realized by a multistage laser-target interaction