Search

Your search keyword '"Joshi, C."' showing total 1,433 results
Start Over Author "Joshi, C." Language english
1,433 results on '"Joshi, C."'

1. Plasma electron acceleration driven by a long-wave-infrared laser

Author

Zgadzaj, R., Welch, J., Cao, Y., Amorim, L. D., Cheng, A., Gaikwad, A., Iapozzutto, P., Kumar, P., Litvinenko, V. N., Petrushina, I., Samulyak, R., Vafaei-Najafabadi, N., Joshi, C., Zhang, C., Babzien, M., Fedurin, M., Kupfer, R., Kusche, K., Palmer, M. A., Pogorelsky, I. V., Polyanskiy, M. N., Swinson, C., and Downer, M. C.

Published
2024
Full Text
View/download PDF

2. Molecular characterization of Kenkatha and Gaolao (Bos indicus) cattle breeds using microsatellite markers

Author

Chaudhari, M. V., Parmar, S. N. S., Joshi, C. G., Bhong, C. D., Fatima, S., Thakur, M. S., and Thakur, S. S

Subjects
Kenkatha cattle, Gaolao cattle, Microsatellite markers, Zoology, QL1-991
Abstract

One hundred forty–five individuals from two cattle breeds, Kenkatha and Gaolao, in India were studied using 25 fluorescently–labelled microsatellite markers. Genetic diversities within and between populations were studied. A total of 197 and 239 distinct alleles were identified across 25 microsatellite loci in Kenkatha and Gaolao cattle, respectively. Means of observed and expected heterozygosity were found to be 0.47 ± 0.24 and 0.62 ± 0.21 in Kenkatha, and 0.53 ± 0.17 and 0.68 ± 0.14 in Gaolao cattle, respectively. The average PIC (Polymorphic Information Content) value was found to be 0.59 ± 0.21 for Kenkatha and 0.65 ± 0.15 for Gaolao cattle. The mean fixation index (FIS) was 0.2121 for Gaolao and 0.2248 for Kenkatha cattle. Mean FIS, mean FIT and mean FST (F–statistics) values were found to be 0.2318, 0.2487 and 0.0219, respectively. Nei’s standard genetic distance value between Kenkatha and Gaolao breeds was 0.0852. The present study indicates that there is a substantial shortfall, 21.21% and 22.48%, of heterozygotes in Gaolao and Kenkatha cattle populations, respectively; and little genetic differentiation (2.19%) between the two breeds.

Published
2009

6. Source size of x rays from self-modulated laser wakefield accelerators.

Author

Pagano, I. M., Lemos, N., King, P. M., Rusby, D., Sinclair, M., Aghedo, A., Khan, S., Downer, M. C., Joshi, C., and Albert, F.

Abstract

A comparative study of x-ray sources generated with different mechanisms from self-modulated laser wakefield acceleration (SM-LWFA) electrons was performed to compare the source size or spatial resolution for use in high energy density science applications. We examine the source size of betatron, inverse Compton scattering, and bremsstrahlung radiation with a Fresnel diffraction based formalism and a modified x-ray ray tracing model. We observe the dependence of source size on the radiation generation process, laser parameters, and compare to what is possible in other regimes of LWFA, as well as current methods. This information is significant as we begin to explore the use of light sources driven by SM-LWFA for use as a diagnostic at large-scale laser facilities where blowout regime LWFA is not possible. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

9. Arginine-Modified Polymers Facilitate Poly (Lactide-Co-Glycolide)-Based Nanoparticle Gene Delivery to Primary Human Astrocytes

Author

Proulx J, Joshi C, Vijayaraghavalu S, Saraswathy M, Labhasetwar V, Ghorpade A, and Borgmann K

Subjects
co-polymer, transfection, gene therapy, astrocyte targeting, nuclear entry, Medicine (General), R5-920
Abstract

Jessica Proulx,1 Chaitanya Joshi,1 Sivakumar Vijayaraghavalu,2 Manju Saraswathy,2 Vinod Labhasetwar,2 Anuja Ghorpade,1 Kathleen Borgmann1,3 1Department of Microbiology, Immunology, and Genetics University of North Texas Health Science Center, Fort Worth, TX, USA; 2Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; 3Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USACorrespondence: Kathleen BorgmannDepartment of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107, USATel +1 817 735-0339Fax +1 817 735-2610Email Kathleen.Borgmann@unthsc.eduPurpose: Astrocyte dysfunction is a hallmark of central nervous system injury or infection. As a primary contributor to neurodegeneration, astrocytes are an ideal therapeutic target to combat neurodegenerative conditions. Gene therapy has arisen as an innovative technique that provides excellent prospect for disease intervention. Poly (lactide-co-glycolide) (PLGA) and polyethylenimine (PEI) are polymeric nanoparticles commonly used in gene delivery, each manifesting their own set of advantages and disadvantages. As a clinically approved polymer by the Federal Drug Administration, well characterized for its biodegradability and biocompatibility, PLGA-based nanoparticles (PLGA-NPs) are appealing for translational gene delivery systems. However, our investigations revealed PLGA-NPs were ineffective at facilitating exogenous gene expression in primary human astrocytes, despite their success in other cell lines. Furthermore, PEI polymers illustrate high delivery efficiency but induce cytotoxicity. The purpose of this study is to develop viable and biocompatible NPsystem for astrocyte-targeted gene therapy.Materials and Methods: Successful gene expression by PLGA-NPs alone or in combination with arginine-modified PEI polymers (AnPn) was assessed by a luciferase reporter gene encapsulated in PLGA-NPs. Cytoplasmic release and nuclear localization of DNA were investigated using fluorescent confocal imaging with YOYO-labeled plasmid DNA (pDNA). NP-mediated cytotoxicity was assessed via lactate dehydrogenase in primary human astrocytes and neurons.Results: Confocal imaging of YOYO-labeled pDNA confirmed PLGA-NPs delivered pDNA to the cytoplasm in a dose and time-dependent manner. However, co-staining revealed pDNA delivered by PLGA-NPs did not localize to the nucleus. The addition of AnPn significantly improved nuclear localization of pDNA and successfully achieved gene expression in primary human astrocytes. Moreover, these formulations were biocompatible with both astrocytes and neurons.Conclusion: By co-transfecting two polymeric NPs, we developed an improved system for gene delivery and expression in primary human astrocytes. These findings provide a basis for a biocompatible and clinically translatable method to regulate astrocyte function during neurodegenerative diseases and disorders.Keywords: co-polymer, transfection, gene therapy, astrocyte targeting, nuclear entry

Published
2020

10. EuPRAXIA Conceptual Design Report

Author

Assmann, R. W., Weikum, M. K., Akhter, T., Alesini, D., Alexandrova, A. S., Anania, M. P., Andreev, N. E., Andriyash, I., Artioli, M., Aschikhin, A., Audet, T., Bacci, A., Barna, I. F., Bartocci, S., Bayramian, A., Beaton, A., Beck, A., Bellaveglia, M., Beluze, A., Bernhard, A., Biagioni, A., Bielawski, S., Bisesto, F. G., Bonatto, A., Boulton, L., Brandi, F., Brinkmann, R., Briquez, F., Brottier, F., Bründermann, E., Büscher, M., Buonomo, B., Bussmann, M. H., Bussolino, G., Campana, P., Cantarella, S., Cassou, K., Chancé, A., Chen, M., Chiadroni, E., Cianchi, A., Cioeta, F., Clarke, J. A., Cole, J. M., Costa, G., Couprie, M. -E., Cowley, J., Croia, M., Cros, B., Crump, P. A., D’Arcy, R., Dattoli, G., Del Dotto, A., Delerue, N., Del Franco, M., Delinikolas, P., De Nicola, S., Dias, J. M., Di Giovenale, D., Diomede, M., Di Pasquale, E., Di Pirro, G., Di Raddo, G., Dorda, U., Erlandson, A. C., Ertel, K., Esposito, A., Falcoz, F., Falone, A., Fedele, R., Ferran Pousa, A., Ferrario, M., Filippi, F., Fils, J., Fiore, G., Fiorito, R., Fonseca, R. A., Franzini, G., Galimberti, M., Gallo, A., Galvin, T. C., Ghaith, A., Ghigo, A., Giove, D., Giribono, A., Gizzi, L. A., Grüner, F. J., Habib, A. F., Haefner, C., Heinemann, T., Helm, A., Hidding, B., Holzer, B. J., Hooker, S. M., Hosokai, T., Hübner, M., Ibison, M., Incremona, S., Irman, A., Iungo, F., Jafarinia, F. J., Jakobsson, O., Jaroszynski, D. A., Jaster-Merz, S., Joshi, C., Kaluza, M., Kando, M., Karger, O. S., Karsch, S., Khazanov, E., Khikhlukha, D., Kirchen, M., Kirwan, G., Kitégi, C., Knetsch, A., Kocon, D., Koester, P., Kononenko, O. S., Korn, G., Kostyukov, I., Kruchinin, K. O., Labate, L., Le Blanc, C., Lechner, C., Lee, P., Leemans, W., Lehrach, A., Li, X., Li, Y., Libov, V., Lifschitz, A., Lindstrøm, C. A., Litvinenko, V., Lu, W., Lundh, O., Maier, A. R., Malka, V., Manahan, G. G., Mangles, S. P. D., Marcelli, A., Marchetti, B., Marcouillé, O., Marocchino, A., Marteau, F., Martinez de la Ossa, A., Martins, J. L., Mason, P. D., Massimo, F., Mathieu, F., Maynard, G., Mazzotta, Z., Mironov, S., Molodozhentsev, A. Y., Morante, S., Mosnier, A., Mostacci, A., Müller, A. -S., Murphy, C. D., Najmudin, Z., Nghiem, P. A. P., Nguyen, F., Niknejadi, P., Nutter, A., Osterhoff, J., Oumbarek Espinos, D., Paillard, J. -L., Papadopoulos, D. N., Patrizi, B., Pattathil, R., Pellegrino, L., Petralia, A., Petrillo, V., Piersanti, L., Pocsai, M. A., Poder, K., Pompili, R., Pribyl, L., Pugacheva, D., Reagan, B. A., Resta-Lopez, J., Ricci, R., Romeo, S., Rossetti Conti, M., Rossi, A. R., Rossmanith, R., Rotundo, U., Roussel, E., Sabbatini, L., Santangelo, P., Sarri, G., Schaper, L., Scherkl, P., Schramm, U., Schroeder, C. B., Scifo, J., Serafini, L., Sharma, G., Sheng, Z. M., Shpakov, V., Siders, C. W., Silva, L. O., Silva, T., Simon, C., Simon-Boisson, C., Sinha, U., Sistrunk, E., Specka, A., Spinka, T. M., Stecchi, A., Stella, A., Stellato, F., Streeter, M. J. V., Sutherland, A., Svystun, E. N., Symes, D., Szwaj, C., Tauscher, G. E., Terzani, D., Toci, G., Tomassini, P., Torres, R., Ullmann, D., Vaccarezza, C., Valléau, M., Vannini, M., Vannozzi, A., Vescovi, S., Vieira, J. M., Villa, F., Wahlström, C. -G., Walczak, R., Walker, P. A., Wang, K., Welsch, A., Welsch, C. P., Weng, S. M., Wiggins, S. M., Wolfenden, J., Xia, G., Yabashi, M., Zhang, H., Zhao, Y., Zhu, J., and Zigler, A.

Published
2020
Full Text
View/download PDF

11. Erratum to: EuPRAXIA Conceptual Design Report: Eur. Phys. J. Special Topics 229, 3675-4284 (2020), https://doi.org/10.1140/epjst/e2020-000127-8

Author

Assmann, R. W., Weikum, M. K., Akhter, T., Alesini, D., Alexandrova, A. S., Anania, M. P., Andreev, N. E., Andriyash, I., Artioli, M., Aschikhin, A., Audet, T., Bacci, A., Barna, I. F., Bartocci, S., Bayramian, A., Beaton, A., Beck, A., Bellaveglia, M., Beluze, A., Bernhard, A., Biagioni, A., Bielawski, S., Bisesto, F. G., Bonatto, A., Boulton, L., Brandi, F., Brinkmann, R., Briquez, F., Brottier, F., Bründermann, E., Büscher, M., Buonomo, B., Bussmann, M. H., Bussolino, G., Campana, P., Cantarella, S., Cassou, K., Chancé, A., Chen, M., Chiadroni, E., Cianchi, A., Cioeta, F., Clarke, J. A., Cole, J. M., Costa, G., Couprie, M. -E., Cowley, J., Croia, M., Cros, B., Crump, P. A., D’Arcy, R., Dattoli, G., Del Dotto, A., Delerue, N., Del Franco, M., Delinikolas, P., De Nicola, S., Dias, J. M., Di Giovenale, D., Diomede, M., Di Pasquale, E., Di Pirro, G., Di Raddo, G., Dorda, U., Erlandson, A. C., Ertel, K., Esposito, A., Falcoz, F., Falone, A., Fedele, R., Ferran Pousa, A., Ferrario, M., Filippi, F., Fils, J., Fiore, G., Fiorito, R., Fonseca, R. A., Franzini, G., Galimberti, M., Gallo, A., Galvin, T. C., Ghaith, A., Ghigo, A., Giove, D., Giribono, A., Gizzi, L. A., Grüner, F. J., Habib, A. F., Haefner, C., Heinemann, T., Helm, A., Hidding, B., Holzer, B. J., Hooker, S. M., Hosokai, T., Hübner, M., Ibison, M., Incremona, S., Irman, A., Iungo, F., Jafarinia, F. J., Jakobsson, O., Jaroszynski, D. A., Jaster-Merz, S., Joshi, C., Kaluza, M., Kando, M., Karger, O. S., Karsch, S., Khazanov, E., Khikhlukha, D., Kirchen, M., Kirwan, G., Kitégi, C., Knetsch, A., Kocon, D., Koester, P., Kononenko, O. S., Korn, G., Kostyukov, I., Kruchinin, K. O., Labate, L., Le Blanc, C., Lechner, C., Lee, P., Leemans, W., Lehrach, A., Li, X., Li, Y., Libov, V., Lifschitz, A., Lindstrøm, C. A., Litvinenko, V., Lu, W., Lundh, O., Maier, A. R., Malka, V., Manahan, G. G., Mangles, S. P. D., Marcelli, A., Marchetti, B., Marcouillé, O., Marocchino, A., Marteau, F., Martinez de la Ossa, A., Martins, J. L., Mason, P. D., Massimo, F., Mathieu, F., Maynard, G., Mazzotta, Z., Mironov, S., Molodozhentsev, A. Y., Morante, S., Mosnier, A., Mostacci, A., Müller, A. -S., Murphy, C. D., Najmudin, Z., Nghiem, P. A. P., Nguyen, F., Niknejadi, P., Nutter, A., Osterhoff, J., Oumbarek Espinos, D., Paillard, J. -L., Papadopoulos, D. N., Patrizi, B., Pattathil, R., Pellegrino, L., Petralia, A., Petrillo, V., Piersanti, L., Pocsai, M. A., Poder, K., Pompili, R., Pribyl, L., Pugacheva, D., Reagan, B. A., Resta-Lopez, J., Ricci, R., Romeo, S., Rossetti Conti, M., Rossi, A. R., Rossmanith, R., Rotundo, U., Roussel, E., Sabbatini, L., Santangelo, P., Sarri, G., Schaper, L., Scherkl, P., Schramm, U., Schroeder, C. B., Scifo, J., Serafini, L., Sharma, G., Sheng, Z. M., Shpakov, V., Siders, C. W., Silva, L. O., Silva, T., Simon, C., Simon-Boisson, C., Sinha, U., Sistrunk, E., Specka, A., Spinka, T. M., Stecchi, A., Stella, A., Stellato, F., Streeter, M. J. V., Sutherland, A., Svystun, E. N., Symes, D., Szwaj, C., Tauscher, G. E., Terzani, D., Toci, G., Tomassini, P., Torres, R., Ullmann, D., Vaccarezza, C., Valléau, M., Vannini, M., Vannozzi, A., Vescovi, S., Vieira, J. M., Villa, F., Wahlström, C. -G., Walczak, R., Walker, P. A., Wang, K., Welsch, A., Welsch, C. P., Weng, S. M., Wiggins, S. M., Wolfenden, J., Xia, G., Yabashi, M., Zhang, H., Zhao, Y., Zhu, J., and Zigler, A.

Published
2020
Full Text
View/download PDF

18. Kinetic theory approach for the determination of rate of evaporation

Author

Haran, Joshi C.

Subjects
541.39
Abstract

The problem of liquid evaporating/condensing from/to its surface is of importance in a wide variety of engineering applications. These can be classified into naturally occurring processes and those that came out of technological advancement. Of the naturally occurring processes the important problems are loss of water due to evaporation in dams, evaporation from moist material to dry it, condensation in droplets required for cloud formation etc. The processes which became important due to technological advancement are evaporation in freeze drying processes, evaporation and condensation required to produce thin films using vacuum coating techniques, drying processes required at ordinary temperatures and pressure to prevent chemical degradation at high temperature and the evaporation process which produce the cooling effect in evaporative cooling towers. The problem in which continuum concepts are valid are analysed using the Fick's Diffusion model. It involves the experimental determination of the diffusion coefficient in each case. Cases where evaporation took place under free molecular regime could not be analysed using the Fick's model. In the present study a Kinetic Theory approach is made to analyse the problem. The analysis is made in two stages. In the first stage, the evaporation from a free liquid surface to its own vapour is studied. In the second stage the study is extended to the case where noncondensable gas is also present along with the vapour. The analysis is carried out using the Boltzmann transport equation. The collision terms in the equation are obtained using the model suggested by Bhatnagar Gross and Krook and now known as the BGK equation. The numerical schemes are developed for both the cases and solutions are obtained for the net rate of evaporation. The distribution of temperature, pressure and molecular number density are also plotted for the region close to the interface. The evaporation coefficient introduced in the theoretical model is obtained by comparison with experimental data. Experiments are conducted with water as the fluid and nitrogen as the inert gas. The correlations are made and the results are presented. The evaporation coefficient was found to be in the range 0.0005 to 0.0007 for the single component case and for the twocomponent case it is found to be in the range 0.0009 to 0.00135. These values can be used for engineering design applications

Published
2005

19. Progress of plasma wakefield self-modulation experiments at FACET

Author

Adli, E., Berglyd Olsen, V.K., Lindstrøm, C.A., Muggli, P., Reimann, O., Vieira, J.M., Amorim, L.D., Clarke, C.I., Gessner, S.J., Green, S.Z., Hogan, M.J., Litos, M.D., O׳Shea, B.D., Yakimenko, V., Clayton, C., Marsh, K.A., Mori, W.B., Joshi, C., Vafaei-Najafabadi, N., and Williams, O.

Published
2016
Full Text
View/download PDF

24. Compression deformation models of cenosphere reinforced polymer syntactic foams.

Author

Chaitanya, Ch. Sri, Chittibabu, G., Mahammod, Babar Pasha, Kumar, T. Bharath, Joshi, C. Pranaya, and Rao, R. Narasimha

Subjects
SYNDIOTACTIC polymers, FOAM, STRAIN rate, COMPRESSION loads, FOAM cells, FRACTIONS, CELL size
Abstract

Syntactic foams are close celled foams with hollow micro balloons used to create porosity in the matrix. In the present study, the single cell of the syntactic foams was modelled using ANSYS. The single celled foam was then compressed and the response to the compressive load was studied. The results obtained from the software are compared with the experimental results. It was found that the effective modulus of the foam obtained from the software are similar to the experimentation results. The effective modulus of the foams was found to be increased with the increase in the volume fraction of the porosity. The effect of the size of the porous cell has negligible effect on the effective modulus similarly the effect of the strain rate of compression is also negligible on the effective modulus of the syntactic foam. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

25. Gain dynamics in a CO2 active medium optically pumped at 4.3 μm.

Author

Tovey, D., Pigeon, J. J., Tochitsky, S. Ya., Louwrens, G., Ben-Zvi, I., Joshi, C., Martyshkin, D., Fedorov, V., Karki, K., and Mirov, S.

Subjects
LASER pumping, TUNABLE lasers, ENERGY storage, ENERGY conversion, TIME-resolved measurements
Abstract

A pulsed ∼2 mJ Fe:ZnSe laser tunable around ∼4.3 μm is used to optically pump mixtures of CO2 and He to create gain at 10 μm. A conventional low-pressure CO2 laser operating on both regular (001-100) and sequence (002-101) bands is used to study the gain dynamics of the optically pumped CO2 amplifier. Time-resolved measurements of the CO2 asymmetric stretching mode vibrational temperature, T3, as well as the translational temperature, T, are made. The measured T3 value of ∼2500 K is much higher than that typically measured in discharge pumped CO2 lasers. High gain coefficients ∼30%/cm in the optically pumped active medium are attributed to the efficient storage of energy in the asymmetric stretching mode and the selective population of the upper laser level. The measured optical-to-optical energy conversion efficiency of ∼30% for 10 μm lasing at sub-atmospheric pressures is close to the theoretical quantum limit of 40% and, thus, supports our claim of gain dynamics optimization. It is concluded that a joule-class 4.3 μm pump laser will be required for the amplification of sub-picosecond 10 μm pulses in a multi-atmosphere optically pumped CO2 active medium. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

26. 14CO2 ACTIVITY IN AIR SAMPLES AND DILUTION FACTOR EVALUATION OF KAKRAPAR GUJARAT SITE, INDIA.

Author

Chandrakar, A, Patra, A K, Joshi, C P, Jain, A, Nankar, D P, Badhai, D, Karthik, S, Saradhi, I V, and Kumar, A V

Subjects
AIR sampling, DILUTION, SOIL sampling
Abstract

14CO2 activity in air samples collected at Kakrapar Gujarat Site, India, was measured, and site-specific dilution factor for 14CO2 has been evaluated. 14CO2 activity in air samples was monitored for 72 different sampling events at onsite stack of Nuclear Power Plant (NPP) and at ESL meteorology laboratory (at 1.6 km from NPP stack). 14CO2 activity in air at stack of NPP and at ESL meteorology laboratory was observed to 0.10–0.18 TBq (GWe.year)–1, with mean value 0.12 TBq (GWe.year)–1 and ≤0.04–0.13 Bq m–3, with mean value 0.08 Bq m–3 respectively. The results were correlated with meteorological parameters. Site specific dilution factor for 14CO2 in air was evaluated at 1.6 km and was found to be in the range of 4.6E-05 to 21E-05 s m–3. Inter angle (degree) between plume direction and fixed sampling location and rainfall (mm) are found to be the important influencing parameters for dilution factor of 14CO2 in air. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

27. Accurate simulation of direct laser acceleration in a laser wakefield accelerator.

Author

Miller, Kyle G., Palastro, John P., Shaw, Jessica L., Li, Fei, Tsung, Frank S., Decyk, Viktor K., Joshi, C., and Mori, Warren B.

Subjects
LASER plasma accelerators, PLASMA waves, LASER plasmas, PLASMA oscillations, LASERS
Abstract

In a laser wakefield accelerator (LWFA), an intense laser pulse excites a plasma wave that traps and accelerates electrons to relativistic energies. When the pulse overlaps the accelerated electrons, it can enhance the energy gain through direct laser acceleration (DLA) by resonantly driving the betatron oscillations of the electrons in the plasma wave. The traditional particle-in-cell (PIC) algorithm, although often the tool of choice to study DLA, contains inherent errors due to numerical dispersion and the time staggering of the electric and magnetic fields. Furthermore, conventional PIC implementations cannot reliably disentangle the fields of the plasma wave and laser pulse, which obscures interpretation of the dominant acceleration mechanism. Here, a customized field solver that reduces errors from both numerical dispersion and time staggering is used in conjunction with a field decomposition into azimuthal modes to perform PIC simulations of DLA in an LWFA. Comparisons with traditional PIC methods, model equations, and experimental data show improved accuracy with the customized solver and convergence with an order-of-magnitude fewer cells. The azimuthal-mode decomposition reveals that the most energetic electrons receive comparable energy from DLA and LWFA. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

34. Multi-gigaelectronvolt acceleration of positrons in a self-loaded plasma wakefield

Author

Corde, S., Adli, E., Allen, J.M., An, W., Clarke, C.I., Clayton, C.E., Delahaye, J.P., Frederico, J., Gessner, S., Green, S.Z., Hogan, M.J., Joshi, C., Lipkowitz, N., Litos, M., Lu, W., Marsh, K.A., Mori, W.B., Schmeltz, M., Vafaei-Najafabadi, N., Walz, D., Yakimenko, V., and Yocky, G.

Subjects
Colliders (Nuclear physics) -- Research, Electron accelerators -- Research, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Electrical breakdown sets a limit on the kinetic energy that particles in a conventional radio-frequency accelerator can reach. New accelerator concepts must be developed to achieve higher energies and to make future particle colliders more compact and affordable. The plasma wakefield accelerator (PWFA) embodies one such concept, in which the electric field of a plasma wake excited by a bunch of charged particles (such as electrons) is used to accelerate a trailing bunch of particles. To apply plasma acceleration to electron-positron colliders, it is imperative that both the electrons and their antimatter counterpart, the positrons, are efficiently accelerated at high fields using plasmas (1). Although substantial progress has recently been reported on high-field, high-efficiency acceleration of electrons in a PWFA powered by an electron bunch (2), such an electron-driven wake is unsuitable for the acceleration and focusing of a positron bunch. Here we demonstrate a new regime of PWFAs where particles in the front of a single positron bunch transfer their energy to a substantial number of those in the rear of the same bunch by exciting a wakefield in the plasma. In the process, the accelerating field is altered--'self-loaded'--so that about a billion positrons gain five gigaelectronvolts of energy with a narrow energy spread over a distance of just 1.3 metres. They extract about 30 per cent of the wake's energy and form a spectrally distinct bunch with a root-mean-square energy spread as low as 1.8 per cent. This ability to transfer energy efficiently from the front to the rear within a single positron bunch makes the PWFA scheme very attractive as an energy booster to an electron-positron collider., Future high-energy particle colliders will operate at the frontier of particle physics, with particle energies in the range of several trillion electronvolts (3). Beyond the Large Hadron Collider (LHC) at [...]

Published
2015

46. The Genome of Black Cottonwood, Populus trichocarpa (Torr. & Gray)

Author

Tuskan, G. A., DiFazio, S., Jansson, S., Bohlmann, J., Grigoriev, I., Hellsten, U., Putnam, N., Ralph, S., Rombauts, S., Salamov, A., Schein, J., Sterck, L., Aerts, A., Bhalerao, R. R., Bhalerao, R. P., Blaudez, D., Boerjan, W., Brun, A., Brunner, A., Busov, V., Campbell, M., Carlson, J., Chalot, M., Chapman, J., Chen, G.-L., Cooper, D., Coutinho, P. M., Couturier, J., Covert, S., Cronk, Q., Cunningham, R., Davis, J., Degroeve, S., Déjardin, A., dePamphilis, C., Detter, J., Dirks, B., Dubchak, I., Duplessis, S., Ehlting, J., Ellis, B., Gendler, K., Goodstein, D., Gribskov, M., Grimwood, J., Groover, A., Gunter, L., Hamberger, B., Heinze, B., Helariutta, Y., Henrissat, B., Holligan, D., Holt, R., Huang, W., Islam-Faridi, N., Jones, S., Jones-Rhoades, M., Jorgensen, R., Joshi, C., Kangasjärvi, J., Karlsson, J., Kelleher, C., Kirkpatrick, R., Kirst, M., Kohler, A., Kalluri, U., Larimer, F., Leebens-Mack, J., Leplé, J.-C., Locascio, P., Lou, Y., Lucas, S., Martin, F., Montanini, B., Napoli, C., Nelson, D. R., Nelson, C., Nieminen, K., Nilsson, O., Pereda, V., Peter, G., Philippe, R., Pilate, G., Poliakov, A., Razumovskaya, J., Richardson, P., Rinaldi, C., Ritland, K., Rouzé, P., Ryaboy, D., Schmutz, J., Schrader, J., Segerman, B., Shin, H., Siddiqui, A., Sterky, F., Terry, A., Tsai, C.-J., Uberbacher, E., Unneberg, P., Vahala, J., Wall, K., Wessler, S., Yang, G., Yin, T., Douglas, C., Marra, M., Sandberg, G., Van de Peer, Y., and Rokhsar, D.

Published
2006

48. High-efficiency acceleration of an electron beam in a plasma wakefield accelerator

Author

Litos, M., Adli, E., An, W., Clarke, C.I., Clayton, C.E., Corde, S., Delahaye, J.P., England, R.J., Fisher, A.S., Frederico, J., Gessner, S., Green, S.Z., Hogan, M.J., Joshi, C., Lu, W., Marsh, K.A., Mori, W.B., Muggli, P., Najafabadi, N. Vafaei, Walz, D., White, G., Wu, Z., Yakimenko, V., and Yocky, G.

Subjects
Plasma accelerators -- Research, Electron beams -- Research, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

High-efficiency acceleration of charged particle beams at high gradients of energy gain per unit length is necessary to achieve an affordable and compact high-energy collider. The plasma wakefield accelerator is one concept (1-3) being developed for this purpose. In plasma wakefield acceleration, a charge-density wake with high accelerating fields is driven by the passage of an ultra-relativistic bunch of charged particles (the drive bunch) through a plasma (4-6). If a second bunch of relativistic electrons (the trailing bunch) with sufficient charge follows in the wake of the drive bunch at an appropriate distance, it can be efficiently accelerated to high energy. Previous experiments using just a single 42-gigaelectronvolt drive bunch have accelerated electrons with a continuous energy spectrum and a maximum energy of up to 85 gigaelectronvolts from the tail of the same bunch in less than a metre of plasma (7). However, the total charge of these accelerated electrons was insufficient to extract a substantial amount of energy from the wake. Here we report high-efficiency acceleration of a discrete trailing bunch of electrons that contains sufficient charge to extract a substantial amount of energy from the high-gradient, nonlinear plasma wakefield accelerator. Specifically, we show the acceleration of about 74 picocoulombs of charge contained in the core of the trailing bunch in an accelerating gradient of about 4.4 gigavolts per metre. These core particles gain about 1.6 gigaelectronvolts of energy per particle, with a final energy spread as low as 0.7 per cent (2.0 per cent on average), and an energy-transfer efficiency from the wake to the bunch that can exceed 30 per cent (17.7 per cent on average). This acceleration of a distinct bunch of electrons containing a substantial charge and having a small energy spread with both a high accelerating gradient and a high energy-transfer efficiency represents a milestone in the development of plasma wakefield acceleration into a compact and affordable accelerator technology., The experiment reported here is carried out in the three-dimensional, nonlinear regime of plasma wakefield acceleration, also known as the blowout regime (8). In this regime, a tightly focused and [...]

Published
2014

Catalog

Books, media, physical & digital resources
See catalog results