Electromagnetic Meissner effect launcher

An electromagnetic projectile launcher provides acceleration of a superconducting projectile through the diamagnetic repulsion of the superconducting projectile. A superconducting layer is provided aft of the projectile, either directly on the projectile or on a platform upon which the projectile is carried, and a traveling magnetic field is caused to propagate along a magnetic field drive coil in which the projectile is disposed. The resulting diamagnetic repulsion between the superconducting projectile and the traveling magnetic field causes the projectile to be propelled along the coil. In one embodiment, a segmented drive coil is used to generate the traveling magnetic field

Emission Characteristics of the Projectile Fragments at Relativistic Energy

A projectile (84^Kr_36) having kinetic energy around 1 A GeV was used to expose NIKFI BR-2 emulsion target. A total of 700 inelastic events are used in the present studies on projectile fragments. The emission angle of the projectile fragments are strongly affected by charge of the other projectile fragments emitted at same time with different emission angle is observed. The angular distribution studies show symmetrical nature for lighter charge projectile fragments. The symmetrical nature decreased with the charge of projectile fragments. At ~4o of emission angle for double charge projectile fragments, the momentum transfer during interaction is similar for various target species of emulsion were observed. We also observed a small but significant amplitude peaks on both side of the big peak for almost all light charge projectile fragments having different delta angle values. It reflects that there are few percent of projectile fragments that are coming from the decay of heavy projectile fragments or any other process.Comment: 32 pages, 17 Figure

On High Explosive Launching of Projectiles for Shock Physics Experiments

The hydrodynamic operation of the `Forest Flyer' type of explosive launching system for shock physics projectiles was investigated in detail using one- and two-dimensional continuum dynamics simulations. The simulations were insensitive to uncertainties in the material properties, and reproduced measurements of the projectile. The most commonly-used variant, with an Al alloy case, was predicted to produce a slightly curved projectile, subjected to some shock heating, and likely exhibiting some porosity from tensile damage. The flatness can be improved by using a case of lower shock impedance, such as polymethyl methacrylate. High-impedance cases, including Al alloys but with denser materials improving the launching efficiency, can be used if designed according to the physics of oblique shock reflection. The tensile stress induced in the projectile depends on the relative thickness of the explosive, expansion gap, and projectile. The thinner the projectile with respect to the explosive, the smaller the tensile stress. If the explosive is initiated with a plane wave lens, the tensile stress is lower than for initiation with multiple detonators over a plane. The previous plane wave lens designs did however induce a tensile stress close to the spall strength of the projectile. The tensile stress can be reduced by changes in the component thicknesses. Experiments to verify the operation of explosively-launched projectiles should attempt to measure porosity induced in the projectile: arrival time measurements may be insensitive to porous regions caused by damaged or recollected material

Penetration depth time history measurement method

A new method for measuring the depth time history of rigid body penetration into brittle materials under a deceleration of ~10^5 g. The method includes: sabot-projectile, sabot-projectile separation and penetration depth detection systems. Relatively small intrinsic time error (3%) and depth error (0.3–0.7 mm) results. Penetration depth time history in a series of 4140 steel projectile penetrations into a mortar are measured at velocities of 100 to 500 m/sec with sufficient accuracy such that differentiation with respect to time yields stopping force, via Newton's second law