The Experts below are selected from a list of 46380 Experts worldwide ranked by ideXlab platform

Hyungjun Kim - One of the best experts on this subject based on the ideXlab platform.

J Badziak - One of the best experts on this subject based on the ideXlab platform.

  • highly efficient accelerator of dense matter using laser induced Cavity Pressure acceleration
    Physics of Plasmas, 2012
    Co-Authors: J Badziak, S Jablonski, T Pisarczyk, P Rączka, E Krousky, R Liska, Milan Kucharik, T Chodukowski, Z Kalinowska, P Parys
    Abstract:

    Acceleration of dense matter to high velocities is of high importance for high energy density physics, inertial confinement fusion, or space research. The acceleration schemes employed so far are capable of accelerating dense microprojectiles to velocities approaching 1000 km/s; however, the energetic efficiency of acceleration is low. Here, we propose and demonstrate a highly efficient scheme of acceleration of dense matter in which a projectile placed in a Cavity is irradiated by a laser beam introduced into the Cavity through a hole and then accelerated in a guiding channel by the Pressure of a hot plasma produced in the Cavity by the laser beam or by the photon Pressure of the ultra-intense laser radiation trapped in the Cavity. We show that the acceleration efficiency in this scheme can be much higher than that achieved so far and that sub-relativisitic projectile velocities are feasible in the radiation Pressure regime.

  • highly efficient acceleration and collimation of high density plasma using laser induced Cavity Pressure
    Applied Physics Letters, 2010
    Co-Authors: J Badziak, T Pisarczyk, E Krousky, T Chodukowski, S Borodziuk, K Masek, J Skala, J Ullschmied, Yongjoo Rhee
    Abstract:

    An efficient scheme of acceleration and collimation of dense plasma is proposed and examined. In the scheme, a target placed in a Cavity coupled with a guiding channel is irradiated by a laser beam introduced into the Cavity through a hole and accelerated along the channel by the Pressure of the ablating plasma confined in the Cavity. Using 1.315 μm, 0.3 ns laser pulse of energy up to 200 J and a thin CH target, it was shown that the energetic efficiency of acceleration in this scheme is an order of magnitude higher than in the case of conventional ablative acceleration.

  • highly efficient acceleration and collimation of high density plasma using laser induced Cavity Pressure
    arXiv: Plasma Physics, 2010
    Co-Authors: J Badziak, T Pisarczyk, E Krousky, T Chodukowski, S Borodziuk, K Masek, J Skala, J Ullschmied, Yongjoo Rhee
    Abstract:

    A novel efficient scheme of acceleration and collimation of dense plasma is proposed and examined. In the proposed scheme, a target placed in a Cavity at the entrance of a guiding channel is irradiated by a laser beam introduced into the Cavity through a hole and accelerated along the channel by the Pressure created and accumulated in the Cavity by the hot plasma expanding from the target and the Cavity walls. Using 1.315-um, 0.3-ns laser pulse of energy up to 200J and a thin CH target, it was shown that the forward accelerated dense plasma projectile produced from the target can be effectively guided and collimated in the 2-mm cylindrical guiding channel and the energetic efficiency of acceleration in this scheme is an order of magnitude higher than in the case of conventional ablative acceleration.

Dean P Neikirk - One of the best experts on this subject based on the ideXlab platform.

  • Micromachined Fabry-Perot Cavity Pressure transducer
    IEEE Photonics Technology Letters, 1995
    Co-Authors: Y Kim, Dean P Neikirk
    Abstract:

    A surface micromachined Fabry-Perot Cavity used as a Pressure sensor has been fabricated using standard IC technology. Dielectric film stacks consisting of layers of silicon dioxide and silicon nitride were used as mirrors. Polysilicon was used as a sacrificial layer that was then removed to form an air gap Cavity. The Fabry-Perot sensor was optically interrogated using a multimode optical fiber. The measured response of the sensor agrees well with theoretical simulation, which takes into account the averaging effect caused by the shape of the deflected mirror in the Cavity.

Matthew S. Dargusch - One of the best experts on this subject based on the ideXlab platform.

  • The Influence of In-Cavity Pressure on Heat Transfer and Porosity Formation During High-Pressure Die Casting of A380 Alloy
    JOM, 2020
    Co-Authors: Matthew S. Dargusch, Gilles Dour, A. Hamasaaid, N. Balasubramani, D. H. Stjohn
    Abstract:

    This paper is concerned with the measurement of thermal properties and in-Cavity Pressures in cold chamber high-Pressure die casting. The influence of in-Cavity Pressure on the casting porosity, heat flux, and heat transfer coefficient has been investigated during die casting of an A380 alloy. The die was instrumented with heat transfer and Pressure sensors to measure these values directly. Direct measurement of the in-Cavity Pressure was found to be more reliable than the metal Pressure calculated from Pressure measurements in the hydraulic system. Variations on the intensification Pressure directly affect the in-Cavity Pressure. Changing the intensification Pressure between 17 MPa and 90 MPa had little effect on the heat flux and heat transfer which likely reach saturation at a lower Pressure during the rapid filling stages. Increases in intensification Pressure reduced the level of porosity within the castings, being most effective up to a value of 67.4 MPa.

  • heat transfer coefficient and in Cavity Pressure at the casting die interface during high Pressure die casting of the magnesium alloy az91d
    Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2008
    Co-Authors: Gilles Dour, C J Davidson, Anwar Hamasaiid, Tahar Loulou, Matthew S. Dargusch, Gary Savage
    Abstract:

    The present article deals with the application of a new measurement method to determine the heat-transfer coefficient (HTC) and the heat flux density at the casting-die interface during high-Pressure die casting (HPDC) and solidification of the magnesium AZ91D alloy. The main measurements during the trial included velocity and the position of the piston that delivers the metal into the die, the Pressure in the die Cavity and at the tip of the piston, the alloy surface temperature, and the die temperature at different depths from the surface of the die. The temperature data were analyzed using an inverse method to determine the HTC at the casting-die interface during solidification. This article examines in detail the influence of the piston velocity and in-Cavity Pressure on heat transfer at the casting-die interface during casting and solidification of the magnesium AZ91D alloy.

  • The influence of Pressure during solidification of high Pressure die cast aluminium telecommunications components
    Journal of Materials Processing Technology, 2006
    Co-Authors: Matthew S. Dargusch, Gilles Dour, N. Schauer, C. Dinnis, George M. Savage
    Abstract:

    The effects of process variables on the quality of high-Pressure die cast components was determined with the aid of in-Cavity Pressure sensors. In particular, the effects of set intensification Pressure, delay time, and casting velocity have been investigated. The in-Cavity Pressure sensor has been used to determine how conditions within the die-Cavity are related to the process parameters regulated by the die casting machine, and in turn the effect of variations in these parameters on the integrity of the final part. Porosity was found to decrease with increasing intensification Pressure and increase with increasing casting velocity. The delay time before the application of the intensification Pressure was not observed to have a significant effect on porosity levels.

Yongjoo Rhee - One of the best experts on this subject based on the ideXlab platform.

  • highly efficient acceleration and collimation of high density plasma using laser induced Cavity Pressure
    Applied Physics Letters, 2010
    Co-Authors: J Badziak, T Pisarczyk, E Krousky, T Chodukowski, S Borodziuk, K Masek, J Skala, J Ullschmied, Yongjoo Rhee
    Abstract:

    An efficient scheme of acceleration and collimation of dense plasma is proposed and examined. In the scheme, a target placed in a Cavity coupled with a guiding channel is irradiated by a laser beam introduced into the Cavity through a hole and accelerated along the channel by the Pressure of the ablating plasma confined in the Cavity. Using 1.315 μm, 0.3 ns laser pulse of energy up to 200 J and a thin CH target, it was shown that the energetic efficiency of acceleration in this scheme is an order of magnitude higher than in the case of conventional ablative acceleration.

  • highly efficient acceleration and collimation of high density plasma using laser induced Cavity Pressure
    arXiv: Plasma Physics, 2010
    Co-Authors: J Badziak, T Pisarczyk, E Krousky, T Chodukowski, S Borodziuk, K Masek, J Skala, J Ullschmied, Yongjoo Rhee
    Abstract:

    A novel efficient scheme of acceleration and collimation of dense plasma is proposed and examined. In the proposed scheme, a target placed in a Cavity at the entrance of a guiding channel is irradiated by a laser beam introduced into the Cavity through a hole and accelerated along the channel by the Pressure created and accumulated in the Cavity by the hot plasma expanding from the target and the Cavity walls. Using 1.315-um, 0.3-ns laser pulse of energy up to 200J and a thin CH target, it was shown that the forward accelerated dense plasma projectile produced from the target can be effectively guided and collimated in the 2-mm cylindrical guiding channel and the energetic efficiency of acceleration in this scheme is an order of magnitude higher than in the case of conventional ablative acceleration.