Nuclear Weapons - basic technology concepts [UNC]

Demon core Manufacturing and early history[edit] The two physicists Harry Daghlian (center left) and Louis Slotin (center right) during the Trinity Test The next bomb of the implosion type had been scheduled to be ready for delivery on the target on the first good weather after August 24th, 1945. We have gained 4 days in manufacture and expect to ship the final components from New Mexico on August 12th or 13th. Marshall added an annotation, "It is not to be released on Japan without express authority from the President", as President Harry S. First incident[edit] On August 21, 1945, the plutonium core produced a burst of neutron radiation that led to physicist Harry Daghlian's death. Second incident[edit] A re-creation of the 1946 experiment. There have been five studies done of the amount of radiation each person involved received in the accident; these are the latest, dated 1978, from a table in this reference: Operation Crossroads[edit] References[edit] Jump up ^ Wellerstein, Alex.

Strong interaction In particle physics, the strong interaction (also called the strong force, strong nuclear force, nuclear strong force or color force) is one of the four fundamental interactions of nature, the others being electromagnetism, the weak interaction and gravitation. At atomic scale, it is about 100 times stronger than electromagnetism, which in turn is orders of magnitude stronger than the weak force interaction and gravitation. It ensures the stability of ordinary matter, in confining the elementary particles quarks into hadrons such as the proton and neutron, the largest components of the mass of ordinary matter. Furthermore, most of the mass-energy of a common proton or neutron is in the form of the strong force field energy; the individual quarks provide only about 1% of the mass-energy of a proton[citation needed]. In the context of binding protons and neutrons together to form atoms, the strong interaction is called the nuclear force (or residual strong force). History[edit]

Wireless, handheld device for ground control of X-47B unmanned aircraft tested The first shore-based trials of the Control Display Unit (CDU) that wirelessly controls the X-47B on the ground (Photo: Northrop Grumman) Image Gallery (2 images) While impressive, unmanned flight is just one of the capabilities required of the Northrop Grumman-built X-47B Unmanned Combat Air System (UCAS) if it is to enter service with the U.S. Navy. Prior to and after any flights, the aircraft also needs to be safely maneuvered around the crowded deck of an aircraft carrier. Northrop Grumman and the U.S. In its first shore-based trials carried out earlier this month at Naval Air Station Patuxent River, Maryland, the handheld device, called a Control Display Unit (CDU), was used to control the X-47B’s engine thrust to roll the aircraft forward, brake and stop, and use its nose wheel steering to execute the tight, precision turns required to maneuver the aircraft into a catapult or out of the landing area following a landing. Source: Northrop Grumman About the Author

The strange case of solar flares and radioactive elements Stanford Report, August 23, 2010 When researchers found an unusual linkage between solar flares and the inner life of radioactive elements on Earth, it touched off a scientific detective investigation that could end up protecting the lives of space-walking astronauts and maybe rewriting some of the assumptions of physics. By Dan Stober L.A. Cicero Peter Sturrock, professor emeritus of applied physics It's a mystery that presented itself unexpectedly: The radioactive decay of some elements sitting quietly in laboratories on Earth seemed to be influenced by activities inside the sun, 93 million miles away. Is this possible? Researchers from Stanford and Purdue University believe it is. There is even an outside chance that this unexpected effect is brought about by a previously unknown particle emitted by the sun. The story begins, in a sense, in classrooms around the world, where students are taught that the rate of decay of a specific radioactive material is a constant. Random numbers

How to Make a Survival Shotgun Editor’s note: This is a guest post from Creek Stewart of Willow Haven Outdoor. As a Survival and Preparedness instructor, I take my line of work very seriously–sometimes too seriously. Occasionally, though, I like to take on survival projects that are just downright fun. This article highlights one of those projects. I’m fortunate in that I’ve been able to turn my passion into my profession–this being the study of Survival and Preparedness. Ultimately your survival needs fall into five main categories. WaterFireShelterSignalingFood Every survival kit must include contents that directly or indirectly meet these five basic survival needs. Mossberg 500 Pump Action Shotgun Before Survival/Zombie Modifications I will now break down each survival modification and detail why it was included in the final build. Ammunition First things first: the gun itself. Your Arsenal: Bird Shot, Buck Shot, and Slugs In addition to hunting, a shotgun is an excellent self-defense weapon. Side Saddle on the Stock Saw

How newer reactors would have survived Fukushima - 25 March 2011 Cookies on the New Scientist website close Our website uses cookies, which are small text files that are widely used in order to make websites work more effectively. To continue using our website and consent to the use of cookies, click away from this box or click 'Close' Find out about our cookies and how to change them Tech Log in Your login is case sensitive I have forgotten my password close My New Scientist Look for Science Jobs This is a preview of the full article New Scientist full online access is exclusive to subscribers. Home|Tech | News How newer reactors would have survived Fukushima 25 March 2011 by Paul Marks Magazine issue 2805. Read more: "Special report: Rescuing nuclear power" THERE'S nothing quite like watching reactor buildings explode on live TV to destroy your faith in nuclear power. The Fukushima reactors are a 40-year-old design. To continue reading this article, subscribe to receive access to all of newscientist.com, including 20 years of archive content. PrintWeb Back to top

Handcuffs Of The Future Administer Shocks And Drugs To The Detained A patent for next-generation handcuffs offers a future in which the detained can be zapped directly from their restraints, and even injected with a medication, sedative, irritant, paralytic, or other fine substance. The patent is called “Apparatus and System For Augmented Detainee Restraint” and is the brainchild of Scottsdale Inventions.The augmentations it offers are truly quite something. The handcuffs are “configured to administer electrical shocks when certain predetermined conditions occur.”

Rheinmetall's 50kW high-energy laser weapon successfully passes tests Practical high-energy laser weapons came a step closer to reality in November as Rheinmetall tested its new 50 kW high-energy weapon laser demonstrator. The series of exercises took place at the German-based group’s Ochsenboden Proving Ground in Switzerland. There the 50 kW laser weapon was tested against a series of targets to show the improvements over last year’s 10 kW version. Designed for air defense, asymmetric warfare and Counter Rocket, Artillery, Mortar (C-RAM) operations, the Rheinmetall laser isn't a single weapon, but two laser modules mounted on Oerlikon Revolver Gun air defense turrets with additional modules for the power supply. The lasers are combined using Rheinmetall's Beam Superimposing Technology (BST) to focus a 30 kW and a 20 kW laser on the same spot. This gives it the destructive power of a single 50 kW laser. The tests set the laser against three different targets. Source: Rheinmetall About the Author Post a CommentRelated Articles

This Defense Contractor Has A Green Side : All Tech Considered Lots of companies make products that don't have much in common, but AeroVironment specializes in two products that are very different — electric vehicle chargers, which keep cars like the Nissan Leaf on the road, and military drones. The Los Angeles-area firm is a leading manufacturer of small unmanned aircraft. This unusual company was the creation of one unusual individual, Paul MacCready. He loved things that fly. "As a youngster, I was very interested in model airplanes, ornithopters, autogyros, helicopters, gliders, power planes ..." But as obsessed as he was with flying things, MacCready never wanted to break the sound barrier like Chuck Yeager or buzz the control tower like Tom Cruise's character, Maverick, in Top Gun. MacCready loved nature, and his dream was to create birds — or re-create them. hide captionThe future of AeroVironment's electric vehicle charger business will depend on U.S. demand for electric cars. Courtesy of AeroVironment Inc. MacCready won the prize.

NASA working on RASSOR robot space excavator Recently we've seen preliminary asteroid mining plans from Planetary Resources and Deep Space Industries, but what about NASA? The government agency would like to do some excavating on the Moon, Mars, and asteroids, too – but it isn't in it for the profit. NASA wants to clear the way for construction projects and mine materials for use by astronauts, and is developing a teleoperated robot called the Regolith Advanced Surface Systems Operations Robot (RASSOR, pronounced "razor") to get the job done. According to NASA, it currently costs about US$4,000 to send a single pound (0.45-kg) payload into space, so keeping RASSOR's weight down is important. The drums scoop at 20 rotations per minute, trimming the top layer of soil to avoid jamming in the dense regolith at lower depths. RASSOR can also overcome rough terrain and even boulders by propping itself up on its arms. Source: NASA via RedOrbit

New water jets to give U.S. Navy littoral combat ships extra punch The purpose of the new jets is to increase the speed of the LCS while lowering running costs ( USS Fort Worth (LCS 3) Image Gallery (5 images) The U.S. Navy is fitting new Rolls Royce water jets to its Littoral Combat Ships (LCS). Originally designed for a cancelled ship program, four of the new Axial-Flow Waterjet Mk-1 engines will be fitted over the next two years to the U.S. View all The new water jets replace earlier commercial jet systems and, according to the Navy, can pump out half a million gallons (1.9 million liters) of high-density seawater per minute, pushing the LCS at over 40 knots (46 mph, 74 km/h) while providing more power for less weight. The engines were developed by Rolls-Royce Naval Marine in collaboration with the Office of Naval Research (ONR) and the Naval Surface Warfare Center, Carderock Division, and their purpose is to increase the speed of the LCS while lowering running costs. Source: US Navy About the Author Post a CommentRelated Articles

World's longest sniper kill - 2.47km twice! The sniper is without doubt the most feared combatant in any theater of war, the best of whom have an array of skills far beyond simply being able to hit human targets at a distance. Snipers are the most cost effective way of killing the enemy. View all Individual snipers routinely account for more kills than entire battalions operating in the same place at the same time, hit the target almost every time, and each bullet costs around €2. Whatsmore, snipers inflict a psychological terror on an enemy force that restricts its ability to operate effectively – when elite snipers are operating, they are invisible close up, and can strike from enormous distance, so nowhere is safe. If you're wondering why it took so long for Harrison's kill to be made public, (it was made last November and only became commonly known in the last few days), understand that the publicity such a feat brings may not necessarily be wanted, or healthy, particularly if you are still "in theater".

Next-generation body armor could be based on ... sponges? Scientists have replicated the flexible-but-tough internal structure of the sea sponge, to create a material that might find use in body armor (Photo: Shutterstock) Image Gallery (2 images) Chances are that if you were heading into battle, you wouldn’t wish that you were covered in sponges. It turns out that the sea sponge, however, has a unique structure that allows it to be flexible while remaining relatively impervious to predators. Sponges’ “skeletons” – their internal structural elements – are made up of tiny interlinked needle-like structures known as spicules. The nanoscale spicules they created incorporate a mixture of the mineral calcite, and a protein found in siliceous sponges known as silicatein-α. A diagram of one of the man-made spicules, with close-ups of its calcite nanobricks When mechanical pressure is applied, the nanobricks remain hard and unyielding, but the connective protein allows the spicule as a whole to bend without breaking. About the Author