Shreya Tripathi

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In 1991 a manuscript describing an instrument for studying magnetized plasmas was published in this journal. The Large Plasma Device (LAPD) was upgraded in 2001 and has become a national user facility for the study of basic plasma physics. The upgrade as well as diagnostics introduced since then has significantly changed the capabilities of the device. All(More)
TheAMPTE(ActiveMagnetosphericParticleTracerExplorers) missionprovided in situmeasurements of collisionlessmomentum and energy exchange between an artificial, photo-ionized barium plasma cloud and the streaming, magnetized hydrogen plasma of the solar wind1–3. One of its most significant findings was the unanticipated displacement of the barium ion ‘comet(More)
Under certain conditions an intense kinetic plasma jet is observed to emerge from the apex of laboratory simulations of coronal plasma loops. Analytic and numerical models show that these jets result from a particle orbit instability in a helical magnetic field whereby magnetic forces radially eject rather than confine ions with sufficiently large(More)
Dramatic eruption of an arched magnetic flux rope in a large ambient plasma has been studied in a laboratory experiment that simulates coronal loops. The eruption is initiated by laser generated plasma flows from the footpoints of the rope that significantly modify the magnetic-field topology and link the magnetic-field lines of the rope with the ambient(More)
A laboratory plasma experiment has been constructed to simulate the eruption of arched magnetic flux ropes (AMFRs e.g., coronal loops, solar prominences) in an ambient magnetized plasma. The laboratory AMFR is produced using an annular hot LaB6 cathode and an annular anode in a vacuum chamber which has additional electrodes to produce the ambient magnetized(More)
Laboratory plasma configurations have been developed which simulate solar coronal loops and astrophysical jets. Observed phenomena include the magnetic pinch effect, magnetic hoop force, restraining of the hoop force by an optional externally applied “strapping" magnetic field, MHD-driven jets and their collimation via the stagnation of convected magnetic(More)
An experimental program underway at Caltech has produced plasmas where the shape is neither xed by the vacuum chamber nor xed by an external coil set, but instead is determined by self-organization. The plasma dynamics is highly reproducible and so can be studied in considerable detail even though the morphology of the plasma is both complex and(More)
A helium ion beam source (23 kV/2.0 A) has been constructed for studying fast-ion physics in the cylindrical magnetized plasma of the large plasma device (LAPD). An inductive RF source produces a 10(19) m(-3) density plasma in a ceramic dome. A multi-aperture, rectangular (8 cm × 8 cm) three-grid system extracts the ion beam from the RF plasma. The ion beam(More)
The interaction between two side-by-side solar prominence-like plasmas has been studied using a four-electrode magnetized plasma source that can impose a wide variety of surface boundary conditions. When the source is arranged to create two prominences with the same helicity ~co-helicity!, it is observed that helicity transfer from one prominence to the(More)
The spectral characteristics of trans-2-[4'-(N,N-dimethylamino)styryl]imidazo[4,5-b]pyridine (t-DMASIP-b) have been investigated using absorption and fluorescence techniques, and compared with 2-(4'-N,N-dimethylamino)imidazo[4,5-b]pyridine (DMAPIP-b). The study reveals that introduction of a C[double bond, length as m-dash]C double bond strongly perturbs(More)