Decades of research on superconductivity and cryogenics yielded results that have been needed for a number of fascinating improvements, mostly in medical and commercial applications. Most of the advancements stem from the ongoing research in to the strange habit and unique properties of superconductivity, which has yet to be completely explained. Superconductivity was initially noticed by Heike Kammerlin Onnes, a Dutch physicist in 1911, who discovered that mercury immersed in liquid helium lost all resistive properties. The Meissner result, seen in 1933 by Walther Meissner, and Robert Oschenfeld brought on a repulsion of natural domains from within a superconducting material, basically the basics behind the Maglev train. The 1962 development of NbTi (Neobium-Titanium) cable by Westinghouse made it possible for sensible applications of superconductivity to begin, initially exhibited through the engineering of superconducting particle accelerators in research laboratories. Obviously, several generations of advancements in neuro-scientific cryogenics occurred through the same time-frame and have made storing and producing cryogenic fluids, increasing the variety and efficiency of superconducting devices. Sandia Laboratories developed a coil-gun primarily for use in the travel networks, with the capacity of starting high-speed trains, and potentially spacecraft, both equally appropriate applications in the civilian areas. The armed service applications have recently been uncovered through the successful use of your superconducting Electromagnetic pulse (EMP) bomb from the Iraqi satellite TV train station in 2003, as well as several successful testing of superconducting rail-guns, the latest by the U. S. Navy by using a 35 MJ rail-gun in 2008. It its simplest form, a coil gun involves a barrel, one or more coils, a power, move, and control electronics. Each coil, and its own corresponding electricity section and gadgets is called a 'stage'. As each 'level' is added, the speed of the projectile is increased through magnetic acceleration. Standard coils are typically wound from specially covered copper wire, called "magnetic line" around a non-conductive coil form. Its comparably poor efficiency (vs. NbTi cable) is offset by low costs and a reliable price-performance proportion. Since no coil weapons have thus far used superconducting coils, no superconducting wire has been necessary in virtually any design, removing the necessity to spend a huge sum of money on wire with benefits that cannot be implemented. All traditional coil guns also have used large, high voltage electrolytic capacitors to provide power to the coils. Utilizing the formula P=EI, the power (P) provided is proportional to the voltage level (E) multiplied by the existing (I), which may easily surpass several kilovolts. The power increase corresponds to a rise in the strength of the magnetic field produced, as well as the amount of heat produced by resistance experienced in the coil. Using (E/R)2(R)= E2/R, I=E /R to analyze the heat made by a coil, the amount of resistance is in charge of the increase in heat generation, as well as the decrease in power due to the resistance experienced by the electronic current. Because the voltage ranking and energy storage of an electrolytic capacitor are inversely proportional, several large, heavy capacitors are had a need to provide enough energy storage to discharge across each stage, in a multi-stage firearm; this amounts to one or more banking companies of capacitors, which occupies a considerable amount of space, and requires bus pubs, voltage regulators, step-up transformers, and additional circuitry to make sure safe and reliable operation. Electrolytic capacitor banking institutions also require a rather extensive the perfect time to charge, so the down-time between each shot can be pretty extended. The recharge time can be reduced by utilizing a diode circuit to transfer excess current by the end of each shot back to the capacitor bank or investment company, which yields a faster recharge time, and, therefore, a faster Rate-of-Fire (RoF). The timing array for standard coil guns typically involves an optical sensor inserted in the coil form, which must be produced of the clear materials, usually restricting potential options to plastic material or glass. Clear plastic coil forms can melt during operation because of the amount of heat dissipated during use. Goblet is mostly unaffected by temperature but is reported to shatter, possibly credited to contracting coils, or the 'shockwave' created by the projectile traveling down the barrel. [1] Both of these options totally limit the scale and power of conventional coil weapons, as dumping large sums of current through standard coil forms immediately makes them useless. Steel coil forms can even be used but are structurally inefficient, due to the need to modify them to prevent damaging eddy currents, which reduces their structural stability. In case of massive heating build-up, the insulation surrounding the cables can melt, shorting to the metallic coil form, resulting in a loud sound, light adobe flash, an explosion, and a large electrical arc. Moving over mechanisms typically include MOSFETs, IGBTs, SCR switches, Display tube switches, and a spark gap. Many of these devices are capable of discharging the high voltages required for the operation of typical coil guns. These options are posted by efficiency from biggest to lowest. Steel oxide-semiconductor field-effect transistors (MOSFETs) are densely compacted transistor arrays which come in a huge variety of types, however the switching types, pMOSFET and nMOSFET, are the ones most appropriate to this issue. [2] Insulated Gate Bipolarized Transistors (IGBTs) are MOSFET-controlled P-N-P-N junctions. [2] Primarily, they were subject to failing and inefficiency but have recently become far cheaper and stronger; increasing the effectiveness of IGBT centered designs. They typically have extremely high pulse-power evaluations, making them very ideal for standard coil-guns and other energy weapons. Silicon Controlled Rectifier switches (SCR switches) are simply just a P-N junction with a gate, when the voltage transferring through the rectifier surpasses the scored voltage, the gate starts, and can conduct; after the voltage reduces, the gate closes again. [2] SCR switches are a highly effective means of turning high voltage current thousands of times per second, making them perfect for pulse-power applications. Display tube switches are simply just the use of your camera flash pipe to trigger the coils, which is very rudimentary and inefficient, usually a staple of the low-level hobbyist tasks. Using a spark space is dangerous and is only suitable for the low voltage demonstration models. Ideally, the barrel of the coil-gun would be produced out of a non-conductive, high-strength metallic, impervious to friction destruction. Since there is no such material, alternatives are rather limited as it pertains to choosing a barrel. All barrels must be metallic, so the problems created by eddy currents are always significant. They need to also be durable and are ideally poor conductors. Barrels should not be easily magnetizable, which means that iron, metallic, and other iron containing alloys aren't a choice. These guidelines limit standard metals to the choices of aluminium or titanium, titanium being preferable due to its significantly reduced conductivity and impressive structural strength. Hard anodized light weight aluminum and titanium are the preferable variations, as they'll not conduct and posses an anodic level that produces impressive material strength and hardness. Chemically dealing with the barrel with special compounds designed to reduce friction and increase toughness and safety, i. e. 'bluing' substances and varnishes, can further enhance the efficiency of the coil-gun system. Having talked about the inefficiencies, history, and components of a typical coil-gun, the newspaper will now discuss the look, components, efficiency, and feasibility of any superconducting coil gun system. This section of the newspaper will also present easy-to-read charts, and furniture, so a clear understanding of the system can be achieved. First, in order to understand how a superconducting coil firearm can work, it's important to imagine the coil-gun and its own systems, so several pictures describing specific components and the machine itself are given to assist in the effort to understand the proposed system. The machine of providing cryogenic liquids to the jacketed coils is the principal need for designs and aesthetic help, as a superconducting coil weapon design is in any other case similar to a standard coil-gun.
Fig. 1 contains four main components: The syndication manifold, the twin jacketed cryogenic cooling system, the Water helium container, and the Water Nitrogen container. The distribution manifold contains a series of automated release valves, similar to those found on common pressure cookers, which operate when the operating pressure exceeds a certain point, launching gas and unnecessary pressure. These valves also avoid the chance of asphyxiation, as gas pressure is released in small amounts, alternatively than in a huge plane of pressurized gas, which will quickly cause lack of consciousness and/or fatality. Ideally, the distribution manifold is created from lightweight aluminum and completely encased in thermal insulation to prevent freeze-burns upon contact with the manifold also to improve the useable life-span of the expensive liquid helium. Capping the finish of the manifold is a pair of pressure gauges that display Psi readings from both the Water Nitrogen and Helium segments; the gauges serve to alert users of potential pressurization hazards, and supports the computation of the coolant vaporization rate. Each cryogenic coolant system includes a porcelain-zirconium coated lightweight aluminum or titanium tube (coil-form) welded inside two cylinders. Each cooling system is self-contained, and during assembly, the air conditioning systems are slid onto the barrel. Contraction of the metals during procedure brings the coolant system and the barrel to a correctly tight fit. Both cylinders form an interior (Liquid helium) and an external (Liquid nitrogen) jacket. The to begin these cylinders includes liquid helium, and completely surrounds the coil-form. The absorption pipe for this cylinder moves through the nitrogen cylinder to increase beyond the machine, so it could be attached to the distributing manifold. The two wires lead from the coil-form exit this cylinder through two small holes and goes by through two similar slots on the exterior jacket. The outside jacket is layered in thermal insulation and contains the exit opening for the internal jacket intake tube and the absorption tube for the liquid nitrogen coat itself. This is shown in Figure 7. The coil-form essentially consists of an exceptionally thin lightweight aluminum or titanium pipe coated in a porcelain zirconium composite, that may satisfy the requirements to be both non-conductive and well suited for cryogenic temps, in addition to its quality sturdiness. The coil form can also consist of a hard-anodized light weight aluminum or titanium cylinder, that may also satisfy the requirements. Anodized metals should not be used to put together the barrel, as the anodized layer has a higher friction coefficient, resulting in degrading performance deficits. Once the air conditioning system is totally assembled, it can be slid onto the barrel, or vice versa, to build the main portion of the weapon system. Having now discussed the cryogenic facet of the superconducting system, this paper will now choose the digital systems essential to operate a superconducting coil-gun. Concerning the power supply of your superconducting coil-gun, it will add a microprocessor managed voltage regulator to insure a reliable current supply and offer adjustments in minor increments to avoid precipitating a quench result. Superconductivity has an interesting problem. Once in the superconductive status, current can persist in the coils indefinitely. Utilizing a conventional switch would not succeed, as the existing could not leave the coils. Thus, a long term magnetic field would be created, suspending the projectile at the center of the field within the barrel. If an abnormal termination leads to the quench result, how can the entire concept work if the pulse operation is required? The answer is based on the use of Josephson junctions to actuate moving over in the superconducting coils. Josephson junctions can be cycled ten times faster than any of the previously mentioned transitioning methods and would yield an extremely high theoretical RoF. Josephson junctions make use of the Josephson Impact, which occurs when current is passed through a cable located next to a pair of superconducting things. The cable creates a magnetic field that decreases the critical current in the insulating layer (i. e. line insulation) between your two objects, leading to amount of resistance to build in the objects. The resistance halts any superconducting procedure. [3] Since this cycle can occur thousands of times per second, Josephson junctions are the perfect device for quickly charging and discharging the coils and is practically the sole known device that would do so. The use of Josephson junctions removes the need to wait around a several minutes to return the coils to a standard state, and due to the ability of Josephson junctions to operate thousands of times per second, a theoretical rate of open fire that could easily go beyond the most effective multi-barrel weapons (i. e. Gatling weapons at 4600 to 10, 000 RPM)[3]. Control circuitry for both standard and super-conducting coil-guns are similar in that they both combine many of the same components, such as lead to logic circuits, VARIAC products, step-up transformers, twin diode-discharge circuits, charging circuits, ability rectifiers, and miscellaneous circuits to point the position of voltages, fee capacity, etc. Extra circuits that are needed for the superconducting variant include; a circuit to monitor the temp, pressure level, and level of the cryogenic coolants, a voltage regulator circuit to guarantee an extremely stable voltage end result to the coils, the circuitry for a simple laser beam timing gate, and the circuitry necessary to operate the Josephson junctions. The technologically complex and currently developing systems of lithium-hybrid ultra capacitors would yield the best option energy storage space device for a coil-gun. [4][5] A device that combines the characteristics of both high-energy storage of the lithium-ion/polymer battery and the wonderful power density of the ultra capacitors offers numerous benefits that define for the shortcomings of both. Additional components (in lieu of a micro-computer) are the Trigger Logic table, laser sensors, power supply circuit, voltage regulator, voltage regulator controller circuit, discharge restoration circuit, and the Timing board. Trigger logic boards are available on most coil weapons, and additionally, on electronic digital paintball markers. These planks control switching whenever a condition (Cause yank) is turned on; once the condition is activated, the logic table closes the swap, allowing a present-day pulse to visit from the power source to the coils. The pulse creates the magnetic field that is triggered for a fraction of another. The timing board is in charge of the activation and deactivation of the coils in a flawlessly tuned sequence. As each laser beam sensor is tripped by the projectile, the timing board deactivates the coil that the circular is entering, and activates the main one directly before it, causing ideal acceleration. The laser sensors themselves are really inexpensive and can be found in children's playthings, also critical in laser-timing gates for velocity computations. The response time of the timing table and laser sensors is extremely crucial to the procedure of these devices, as efficiency and electric power will be greatly reduced if the timing series is not perfect. Once the collection is complete, any excess current leaves the coils through a set of Diodes performing as a recovery circuit, and is went back to the capacitors. The lack of level of resistance from the coils and the very cooled operation avoids most of the energy from being lost as heat. A lot of the unwanted energy used for each and every shot can be came back to the capacitors, which have an approximate 90%+ efficiency ranking, which lovers with the efficiency of the coils resulting in an extremely efficient design. [4][5] One of the main great things about a superconducting device is the advantage of not necessitating high voltages, and therefore, the heavy, expensive, and dangerous high voltage components (1 to 20+kV) that accompany such a design. The reduced voltage requirements (1. 7V+) of the coils means that the whole device can be produced of components that are less costly, lighter, more efficient, and way safer. The basic idea of the electronic digital section is to create a stable, low voltage power, a Josephson junction moving over capability, a precise timing board, and an effective Trigger logic board. Those will be the necessary groups necessary for operation, comprised of components described, and discussed immediately prior.
Factor
Increases:
Decreases:
Efficiency
Power
Coil period Increase
Field Strength, length of magnetic field
Efficiency, reduces available barrel length
Varies
^
Voltage increase
Field Strength
Safety requires circuitry adjustment.
Varies
^
Temperature Decrease
Conductivity
Creates heat related issues
^
^
Increase in barrel, or coil-form thickness
Durability, structural strength
Field strength
v
v
Pressure increase in cryogenic tanks
Usability of manifold system
Presents potential explosive hazard
^
Increase in burst drive/pressure comfort ratings
Usability of manifold system, (not dependant on gravity supply)
Presents potential explosive threat, and asphyxiation
^
Abnormal Termination of Procedure (Quench)[5]
Causes catastrophic failure, potential weapon value.
Field power, entropy, electric current, spike in localized magnetic domains (EMP potential), extreme vaporization of cryogenic fluids
Safety, presents multiple lethal risks, explosive, arc, voltage dump, EMP potential, Magnetic shattering, shrapnel, asphyxiation, concussive blast.
Unknown
^
Projectile Mass
Varies with field durability and projectile's metallic properties
Varies with field strength and projectile's metallic properties
Varies
Varies
Projectile Density
Varies with field power and projectile's metallic properties
Varies with field power and projectile's metallic properties
Varies
Varies
Projectile Magnetic Permeability
This increases the speed at which the projectile can be accelerated
Increases saturation rate, reducing re-usability.
^
^
Saturation Rate
No positive effects
Magnetically Saturated projectiles are less efficient than non-saturated projectiles
v
v
Number of coil layers
Increases vitality and efficiency, but only the first two levels have significant effects
Increases size, weight, cost.
^
^
Wire Gauge
Higher Gauge= less amount of resistance, less current handling and heating dissipation
Dissipation.
Lower Measure= more level of resistance, more current handling, more heat, bigger coil size
^
v
Distance of Projectile from Middle of coil
Closer - Field strength boosts, EXCEPT in superconducting areas, where durability is homogeneous throughout
Varies with projectile span, size, coil duration and size, field power, timing method, and projectile properties.
Varies,
When
Optimized, ^
Varies,
When Optimized,
^
Pulse duration
Needs to be extremely exact, optimized pulse duration yields massive rises in efficiency and power
If pulse length of time is not timed appropriately, the projectile will lose velocity, perhaps approaching to a stop in the barrel.
Varies, when Optimized, ^
Varies, when Optimized, ^
Barrel Thickness
Increases stableness, structural strength
Reduces vitality and efficiency, as it does increase the length from field to projectile, and it is also subject to materials permeability ratings
v
v
Barrel material composition
Conductive - requires slotting to avoid eddy currents, can be thinner, increasing vitality and efficiency,
Non-conductive, may be poor, lacks durability, possible friction-ignition.
Varies
Varies
Wire material composition
Different metallic properties have an impact on conductivity, ductility, level of resistance, durability, etc
NbTi cable properties:
Very high conductivity
Low temp-superconductor
Low resistance
Brittle
If low resistance ^
If low resistance ^
Barrel Friction coefficient
If coefficient is low, then friction losses will be minimal, prolonging barrel life.
If coefficient is high, then friction will certainly reduce projectile speed, efficiency, and create temperature destruction and barrel wear.
v
v
Barrel Magnetic permeability
If high, then projectile could be more easily magnetized, increasing efficiency and power
If low, then projectile will take longer to become magnetized
^
^
Given the great array of adjustable factors listed above, computing any kind of field level, efficiency, velocity, or nearly some other facet of coil-gun operation is basically impossible to do without actually creating a device to check and acquiring hard data. The most effective way to compute these critical factors is to perform several tests to achieve a couple of data, average the results, use a spreadsheet to list these results, and graph the info on a calculator or specialized computer program. While it would be delightful to show the efficiency, speed, and field power of the superconducting coil weapon suggested in this newspaper, the design guidelines and test data simply do not can be found for computations to be possible. At best, supposing theoretical parameters were used for many components, approximately fifteen distinct formulas would have to be utilized to obtain 'ball-park' results. The pure number of parameters and miscellaneous 'x factors' would horribly skew those results anyways, so that it is pointless, if not impossible, to accurately calculate theoretical efficiency and velocity with out a test model. However, put simply: Efficiency for a superconducting coil gun starts at a theoretical 99%. For every factor or variable considered, efficiency can only just become reduced, or continue to be the same. Presuming an effective design, perfect timing sequences, and nominal friction loss, efficiency could ballpark 70-90%. The velocity can be computed by using the parameters necessary for the theoretical 99% efficiency rating and the estimation provided predicated on the myriad of factors concerning vitality output. However, velocity can be determined using existing formulas already derived from the assessment of traditional coil-guns, as the basic mechanisms remain the same and, therefore, nominal deviation from the typical form is to be expected due to the device utilizing superconducting coils. Efficiency is determined by dividing the insight value on the result value, which is determined by measuring the input energy, and the outcome energy (in joules). Energy input is the current put on the coils in each pulse, while Energy outcome can be either speed, or the energy produced upon impact. That is a greatly simplified form of the equation sets presented following the glossary. What remains easily quantifiable is that a superconducting coil gun will undoubtedly produce greater efficiency and electricity. The only left over difficulty is calculating how much of an increase it yields. However, the only real reliable way to look for the efficiency and projectile speed would be on a case-by-case basis, and design parameters would play the largest role in identifying each device's theoretical efficiency and vitality output.
While this newspaper has thoroughly discussed the feasibility and probability of a working and effective superconducting coil weapon and found the look and implementation completely feasible, actual lab tests are had a need to acquire any concrete results, due to the numerous factors impacting theoretical computations. At around $200 per meter, NbTi line is definately not inexpensive, making hobbyist checks nearly impossible to fund. Military services research facilities possess the money and tools at their removal but are currently focused on the pursuit of laser based weaponry, and rail-gun development regardless of the numerous advantages a superconducting coil-gun has over the rail-gun:
Far less expensive
Minimal barrel wear
No need for several Megajoule (MJ) pulse electric power supplies
Far more compact
Far more efficient
No aerosol of explosive metal particles and 'plasma plume' pursuing each shot
The next rational part of the quest for a superconducting coil-gun would simply be to obtain funding, and start research and development. Perhaps in the future, the armed service or private pursuits will pursue this goal, leading to further research and developments in the domains of cryogenics, superconductivity, and energy storage area, with the potential result of the effective fielding of a superconducting coil-gun weapon system.
Acknowledgements
The author would like to give thanks to his three research lovers: Avery Hill, Felipe Petroff de Olivera, and Matthew Wirth. He would also prefer to give thanks to Brian Burdyl for his advice about important electromagnetic theory, and for providing a sample research paper to see format and style. Expert Assistance and editing and enhancing and review were important, and were provided by the next individuals: Carol Hollen, Mr. and Mrs. Towle, Patricia Osbourne, Brenda Crain, Allen Upchurch, Andrea Jurgens, Michael Houck, and Brian Burdyl. Special thanks go out to his parents Tommy and Heather Maddox for his or her continuing support throughout the project, along with numerical assistance, and help digitizing the designs. Additional thanks a lot venture out to Ms. Hill for bringing the study group a McDonald's lunch time at the library.
