Demining - AbsoluteAstronomy.com

Demining or mine clearance is the process of removing either land mine

Land mine

A land mine is usually a weight-triggered explosive device which is intended to damage a target—either human or inanimate—by means of a blast and/or fragment impact....

s, or naval mine

Naval mine

A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...

s, from an area, while minesweeping describes the act of detecting of mines. There are two distinct types of mine detection and removal: military and humanitarian.

Minesweepers use many tools in order to accomplish their task. Tools have historically included many trained animals, including dogs and rats, but most often in the modern world minesweepers rely on metal detectors or vehicles with a wide variety of mechanical tools attached to them. There also are or have been other methods developed to detect mines, including the use of trained marine mammals, bacteria, acoustics, and other more exotic methods.

Military mine clearance

In the combat zone, the process is referred to as mine clearance. According to the doctrine of the U.S. and other armies, mine clearance is carried out by combat engineers

Combat engineering

A combat engineer, also called pioneer or sapper in many armies, is a soldier who performs a variety of construction and demolition tasks under combat conditions...

.

The military priority is to breach the minefield quickly in order to create a safe path for troops or ships. Speed is vital, both for tactical reasons and because units attempting to breach the minefield may be under enemy fire. Both anti-personnel mines and anti-tank mines also must be removed, although only in the lanes through which troops or vehicles are planned to advance.

The risk to sappers is far greater because they may be called upon to perform clearance as tactics dictate, including in all-weather conditions and on schedule. Command may accept casualties in the process. Furthermore, it is accepted that mine clearance will be imperfect and there may be casualties from undiscovered mines. One advantage is that, in military operations, sappers are dealing with recently-laid mines that respond predictably to clearance, have not 'migrated', and have not degraded (unless old stock was used). In this they are often aided by technical intelligence

Technical intelligence

In a pure military context, Technical Intelligence is intelligence about weapons and equipment used by the armed forces of foreign nations .The related term, scientific and technical intelligence, addresses information collected at the strategic level.Technical intelligence is intended primarily...

on current adversary of mine types, which are usually of a single type.

In these mine clearance operations, the methods that are applied for detection and removal are quicker, but less exacting. These methods include those that detect and remove in a single action, such as mechanical demining, carpet bombing

Carpet bombing

Carpet bombing is a large aerial bombing done in a progressive manner to inflict damage in every part of a selected area of land. The phrase invokes the image of explosions completely covering an area, in the same way that a carpet covers a floor. Carpet bombing is usually achieved by dropping many...

, burning of the land or the use of Bangalore torpedo

Bangalore torpedo

A Bangalore torpedo is an explosive charge placed on the end of a long, extendible tube. It is used by combat engineers to clear obstacles that would otherwise require them to approach directly, possibly under fire...

es or mine-clearing line charge

Mine-clearing line charge

A mine-clearing line charge is used to create a breach in minefields under combat conditions. While there are many types, the basic design is for many explosive charges connected on a line to be projected onto the minefield. The charges explode, detonating any buried mines, thus clearing a path...

Humanitarian demining

In times of relative peace, the process of mine removal is referred to as demining. This is a thorough, time-intensive process that seeks to locate all mines so that the land or sea area may be safely returned to normal use. It is vital that this process be exhaustive. Even if only a small handful of mines remain undiscovered, incomplete demining can actually lead to an increase in civilian mine casualties as local people re-occupy an area they previously avoided in the belief that it has been made safe. In this context demining is one of the tools of mine action

Mine action

Mine action is a domain within humanitarian aid and development studies concerned with activities which aim to reduce the social, economic and environmental impact of landmines and the explosive remnants of war...

. Coordinated by Mine Action Coordination Center

Mine Action Coordination Center

A Mine Action Coordination Centre is an agency established in a region under the auspices of the United Nations to coordinate the clearing of the explosive remnants of war - including landmines and unexploded ordnance...

s run by the United Nations

United Nations

The United Nations is an international organization whose stated aims are facilitating cooperation in international law, international security, economic development, social progress, human rights, and achievement of world peace...

or a host government, civilian mine clearance agencies

Mine clearance agencies

A mine clearance agency, or demining agency, is an organization involved in removal of landmines and Unexploded Ordnance for military, humanitarian, or commercial reasons....

are tasked with the demining. In post-conflict areas, minefields are often contaminated with a mixture of explosive remnants of war

Explosive remnants of war

Explosive remnants of war is a term used in the humanitarian aid and sustainable development domains to describe the explosive threats remaining in post-conflict society...

(ERW) that includes unexploded ordnance

Unexploded ordnance

Unexploded ordnance are explosive weapons that did not explode when they were employed and still pose a risk of detonation, potentially many decades after they were used or discarded.While "UXO" is widely and informally used, munitions and explosives of...

as well as landmines. In that context, the humanitarian clearance effort is often referred to as battle area clearance.

In some situations, clearing landmines is a necessary condition before other humanitarian programs can be implemented. A large-scale international effort has been made to test and evaluate existing and new technologies for humanitarian demining, notably by the EU, US, Canadian and Japanese governments and by the Mine Action Centres of affected countries.

Current humanitarian demining methods

The main methods used for humanitarian demining on land are: manual detection using metal detector

Metal detector

A metal detector is a device which responds to metal that may not be readily apparent.The simplest form of a metal detector consists of an oscillator producing an alternating current that passes through a coil producing an alternating magnetic field...

s and prodders, detection by specially trained mine detection dogs, and mechanical clearance using armored vehicles fitted with flails

Mine flail

A mine flail is a vehicle-mounted device that makes a safe path through a mine-field by deliberately detonating land mines in front of the vehicle that carries it. They were first used by the British during World War II....

, tiller

Tiller

A tiller or till is a lever attached to a rudder post or rudder stock of a boat that provides leverage for the helmsman to turn the rudder...

or similar devices. There is an organization, APOPO

APOPO

APOPO, an acronym for Anti-Persoonsmijnen Ontmijnende ProductOntwikkeling , is a registered Belgian NGO which trains African giant pouched rats to detect landmines and tuberculosis. APOPO's mission is to develop detection rats technology to provide solutions for global problems and inspire positive...

, that is training African rats to detect landmines much as dogs do, offering a local solution to countries in Africa. In many circumstances, the only method that meets the United Nations' requirements for effective humanitarian demining, the International Mine Action Standards (IMAS), is manual detection and disarmament. The process is typically slow, expensive and dangerous, although demining can be safer than construction work if procedures are followed rigorously. New technologies may provide effective alternatives.

Manual detection with a metal detector

Metal detectors were first used, after their invention by the Polish officer Józef Kosacki

Józef Kosacki

Józef Stanisław Kosacki was a Polish professor engineer, inventor, and an officer in the Polish Army during World War II. He is best known as the inventor of the Polish mine detector, the first man-portable mine detector, whose basic design has been in use with various armies for over 50...

. His invention known as Polish mine detector

Polish mine detector

The Mine detector Mark I was a metal detector for landmines developed during World War II in the winter of 1941–1942 by Polish lieutenant Józef Kosacki.- History :...

Allies used to clear the German mine fields during the Second Battle of El Alamein

Second Battle of El Alamein

The Second Battle of El Alamein marked a major turning point in the Western Desert Campaign of the Second World War. The battle took place over 20 days from 23 October – 11 November 1942. The First Battle of El Alamein had stalled the Axis advance. Thereafter, Lieutenant-General Bernard Montgomery...

when 500 units were shipped to Field Marshal Montgomery.

The first step in manual demining is to scan the area with metal detector

Metal detector

s, which are sensitive enough to pick up most mines but which also yield about one thousand false positives for every mine. Some mines, referred to as minimum metal mine

Minimum metal mine

A minimum metal mine is a land mine that is designed to use the minimum amount of metal in its construction . Both minimum metal anti-tank and anti-personnel mines exist. Some designs contain almost no metal at all...

s, are constructed with as little metal as possible - as little as 1 gram (0.035273962105112 oz) - to make them difficult to detect. Mines with no metal at all have been produced, but are rare. Areas where metal is detected are carefully probed to determine if a mine is present; the probing must continue until the object that set off the metal detector is found.

Dogs

Well-trained dog

Dog

The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...

s can sniff out explosive chemicals like TNT in landmines, and are used in several countries.

Rats

Like dogs, Giant pouched rat

Giant pouched rat

The giant pouched rats of sub-Saharan Africa are large muroid rodents. Their head and body length ranges from 25–45 cm with scaly tails ranging from 36–46 cm...

s are being trained to sniff out chemicals like TNT in landmines. These rats are currently working in minefields in Mozambique

Mozambique

Mozambique, officially the Republic of Mozambique , is a country in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west and Swaziland and South Africa to the southwest...

and are trained in Tanzania by APOPO

APOPO

. The rats are called HeroRATS.

These animals also have the advantage of being far lower mass than the typical human. They are less likely to set off small mines intended to injure or kill people, if the bomb-sniffing animal crosses directly over the top of a buried mine.

Mechanical clearance

Special machines effectively combine mine detection and removal into one operation. In the past, these machines were applied in both mine clearance and demining but are now generally used only for demining. They can be used to verify land that is not expected to be contaminated or as an extra layer of security after an area has been cleared by another method, such as dogs.

The machines consist of a special vehicle that is driven through the minefield, deliberately detonating the mines it drives over. These vehicles are designed to withstand the explosions with little damage. Some are operated directly with armour to protect the driver; some are operated under remote control.

Mine roller
Mine roller
A mine roller or mine trawl is a demining device mounted on a tank or armoured personnel carrier, designed to detonate anti-tank mines. It allows engineers to clear a lane through a minefield which is protected by enemy fire....

s and mine flail
Mine flail
A mine flail is a vehicle-mounted device that makes a safe path through a mine-field by deliberately detonating land mines in front of the vehicle that carries it. They were first used by the British during World War II....

s. The roller method originated during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

and the flail method during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

but both are still used. Neither system is completely reliable and both will leave undetonated mines, requiring the minefield to be rechecked by another method. Mine flail effectiveness can approach 100% in ideal conditions, but clearance rates as low as 50–60% have been reported. This is well below the 99.6% standard set by the United Nations for humanitarian demining.
Mine plow
Mine plow
A mine plow is a tank-mounted device designed to clear a lane through a minefield, allowing other vehicles to follow. Buried land mines are plowed up and pushed outside the tank's track path or tipped over...

- a device in front of a tank that excavates the ground, exposing any mines or turning them upside down, which significantly lessens their effects if they explode.
Modified long-armed demining bulldozer
Bulldozer
A bulldozer is a crawler equipped with a substantial metal plate used to push large quantities of soil, sand, rubble, etc., during construction work and typically equipped at the rear with a claw-like device to loosen densely-compacted materials.Bulldozers can be found on a wide range of sites,...

s are being used in a number of countries. It has the capability to remove vegetation before demining and can withstand antipersonnel and antitank landmines. Its long arms give it the benefit of reducing damage to the main body, especially to the operator's cab. Three inch (7.62 cm) thick bulletproof
Bulletproof
Bulletproofing is the process of making something capable of stopping a bullet or similar high velocity projectiles e.g. shrapnel. The term bullet resistance is often preferred because few, if any, practical materials provide complete protection against all types of bullets, or multiple hits in the...

glass protects the operator from directional mines.

Recently, armies developed armored demining vehicles, and a specially armored bulldozer

Armored bulldozer

The armored bulldozer is a basic tool of combat engineering. These combat engineering vehicles combine the earth moving capabilities of the bulldozer with armor which protects the vehicle and its operator in or near combat. Most are civilian bulldozers modified by addition of vehicle armor/military...

s, that are remote controlled. This terminates the risk to life of the operator. Notable examples are the Caterpillar D7

Caterpillar D7

The Caterpillar D7 is a medium bulldozer manufactured by Caterpillar Inc.. The first D7 appeared in 1938. The D7C came next in 1955. The D7D came in 1959. The 160hp D7E in 1961...

MCAP (USA) and Raam HaShachar Caterpillar D9

Caterpillar D9

Caterpillar D9 - General Characteristics Engineering Role: Heavy bulldozer Propulsion: Caterpillar tracks Engine model:CAT C18 ACERT 3408 HEUI Gross power: 464 hp D9T 474 hp D9R...

N (Israel

Israel

The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

Personal protective equipment

Deminers may be issued personal protective equipment

Personal protective equipment

Personal protective equipment refers to protective clothing, helmets, goggles, or other garment or equipment designed to protect the wearer's body from injury by blunt impacts, electrical hazards, heat, chemicals, and infection, for job-related occupational safety and health purposes, and in...

(PPE) such as helmets, visors, armoured gloves, vests and boots, in an attempt to protect them if a mine is set off by accident. IMAS specifies standards for such equipment but draws attention to its limitations and states that at close quarters, antipersonnel fragmentation mines and antitank mines overmatch PPE currently available. PPE can afford significant protection against antipersonnel blast mines, and these are more common. Related technologies that have been developed to improve safety include large, pillow-like pads strapped to the bottoms of shoes that distribute weight and dull the impact of footsteps, as very slight disturbances of the ground can tip off old, unstable, or intentionally sensitive mine triggers.

Removal methods in demining

In demining, once an object has been detected it is removed by one of the following methods:

Manual disarmament.
Remote burning of the explosive. Where possible, it is better to burn the explosive without detonation. Diethylene triamine
Diethylene triamine
Diethylenetriamine is an organic compound with the formula HN2. This colourless hygroscopic liquid is soluble in water and polar organic solvents, but not simple hydrocarbons. Diethylenetriamine is structural analogue of diethylene glycol. Its chemical properties resemble those for ethylene...

(a close relative of ethylenediamine) reacts with TNT to generate heat. The compound that results from this reaction can then be combusted without detonation. It has been reported that this amine is hypergolic with TNT, Tetryl
Tetryl
2,4,6-Trinitrophenylmethylnitramine commonly referred to as tetryl is a sensitive explosive compound used to make detonators and explosive booster charges....

, Composition B
Composition B
Composition B, colloquially "comp B", is an explosive consisting of castable mixtures of RDX and TNT. It is used as the main explosive filling in artillery projectiles, rockets, land mines, hand grenades, sticky bombs and various other munitions...

and other TNT based explosives, but it does not react in the same way with RDX or PETN
PETN
Pentaerythritol tetranitrate , also known as PENT, PENTA, TEN, corpent, penthrite , is the nitrate ester of pentaerythritol. Penta refers to the five carbon atoms of the neopentane skeleton.PETN is most well known as an explosive...

-based explosives. Other nitrogen-containing organic ligands (e.g. pyridine
Pyridine
Pyridine is a basic heterocyclic organic compound with the chemical formula C5H5N. It is structurally related to benzene, with one C-H group replaced by a nitrogen atom...

, diethylamine
Diethylamine
Diethylamine is a secondary amine with the molecular structure CH3CH2NHCH2CH3. It is a flammable, strongly alkaline liquid. It is miscible with water and ethanol. It is a colorless liquid which often appears brown due to impurities...

and pyrole) are known to be hypergolic with TNT.
Setting the mine on fire while avoiding high-order detonation. This can be done by cutting holes in the mine without detonating its contents.

Removal methods in mine clearance

Some removal methods that are not applied in humanitarian demining, but are common in mine clearance, include:

The Bangalore Torpedo
Bangalore torpedo
A Bangalore torpedo is an explosive charge placed on the end of a long, extendible tube. It is used by combat engineers to clear obstacles that would otherwise require them to approach directly, possibly under fire...

that clears a path through a minefield. This can also be done using the Antipersonnel Obstacle Breaching System
Antipersonnel Obstacle Breaching System
The Anti-Personnel Obstacle Breaching System is an explosive line charge system that allows safe breaching through complex antipersonnel obstacles, particularly fields of land mines. The Anti-Personnel Obstacle Breaching System is joint DOD program for the U.S. Army and the United States Marine...

or Giant Viper
Giant Viper
The Giant Viper is a trailer-mounted, vehicle-pulled, mine clearance system, designed to be deployed in areas containing land mines. It was developed for the British Army in the 1950s...

, a hose-pipe filled with explosives and carried across a minefield by a rocket.
Helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

s dragging a plow to overturn or detonate mines. This has the problem of bringing down the helicopter when the plow snags onto objects such as large rocks, but has been corrected by use of pressure-sensitive plow rakes which release when over-pressured. This does, however, affect its effectiveness as mines planted in hard ground or near rocks will not be detonated.
Cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

and other heavy livestock are often left to graze in mined areas in order to facilitate mine detonation.
The Nazi Germans used captured civilians who were chased across minefields to detonate the explosives. According to Laurence Rees, "Curt von Gottberg
Curt von Gottberg
Curt von Gottberg was a Nazi official and military commander. Beginning in October 1942, within a few years he had personally combined the highest civil and military powers in occupied Belarus: from March 1943 as representative of the HSSPF for central Russia, and from October 1943 as the acting...

, the SS-Obergruppenfuhrer who, during 1943, conducted another huge anti-partisan action called Operation Kottbus
Operation Cottbus
Operation Cottbus was an anti-partisan operation during the occupation of Belarus by Nazi Germany. The operation began on May 20, 1943 during the World War II occupation of northern Belarus in the areas of Begoml, Lepel and Ushachy...

on the eastern border of Belorussia, reported that 'approximately two to three thousand local people were blown up in the clearing of the minefields'."

Case study

Along the China-Vietnam border were numerous minefields. These are the legacy of the border clashes in the 80's. The mines are mainly anti-personnel, and have kept large areas of arable land from use by local farmers. A typical demining process deployed by the Chinese is as follows. Firebreaks are dug around the minefield to be cleared. Then engineers would set the minefield on fire with flamethrowers. Key factors of this burning process are: thick vegetation covering the minefields; most anti-personnel mines are buried very close to the ground level; the mines are made of mostly either wood, thin metal or plastic. This burning process would usually destroy about 90% of the mines, as the mines are either detonated or melted. Mines which have trip wires would have these wires burned off. Demining teams then would plow the area with mine detectors. When the teams have cleared the mines, they would walk over the field hand in hand themselves to show to the locals that all the mines have been cleared.

Detection methods under development

In 2003, the Rand Corporation published a comprehensive report on innovative methods of land mine detection.

Ground penetrating radar

Conventional metal detectors rely on electromagnetic signals with frequencies of the order of 10–100 kHz, which are not sensitive to plastic or wooden mine bodies and the high explosive block itself. The only part of a low-metal mine that they may be able to detect is the detonator. Much higher frequency signals (of the order of 1 GHz) are employed in Ground Penetrating Radar (GPR) and these signals are also sensitive to the non-metallic parts of the mine. Unfortunately, as they are also affected by innocuous objects such as tree roots and stones and by local changes in soil moisture, it is difficult to distinguish a mine on a GPR image.

Dual-sensor

A hybrid approach employing both GPR and metal detector sensors in a single instrument has been developed by several companies and research organisations.

Honey bees

Recent research by the University of Montana has revealed that honey bee

Honey bee

Honey bees are a subset of bees in the genus Apis, primarily distinguished by the production and storage of honey and the construction of perennial, colonial nests out of wax. Honey bees are the only extant members of the tribe Apini, all in the genus Apis...

s can, with minimal training, be used to detect landmines with a far greater accuracy and far higher clearance rate than dogs or rats.

Mammals

Recent experiments with the Gambian giant pouched rat, also known as the Giant African Pouched Rat, have indicated that it has the required sensitivity to smell, can be trained reliably with food-reward incentives, and is typically too small to set off the mines. These rats also offer a local solution to many African countries because they are indigenous to East Africa. These rats are trained by a non-profit, research organization called APOPO

APOPO

and are called HeroRATs.
Additionally, experiments with electrode-guided rats suggest that demining could one day be accomplished by guiding "ratbots" into areas that humans are unable to reach.

Engineer Thrishantha Nanayakkara and colleagues at the University of Moratuwa in Sri Lanka have come up with a method where a dwarf mongoose

Dwarf Mongoose

The Common Dwarf Mongoose , sometimes just called the Dwarf Mongoose, is a small African carnivore belonging to the mongoose family .-Physical characteristics:...

is trained to detect landmines by smell and guided by a remote-controlled robot.

The U.S. Navy Marine Mammal Program

U.S. Navy Marine Mammal Program

The U.S. Navy Marine Mammal Program is a program administered by the U.S. Navy which studies the military use of marine mammals—principally Bottlenose Dolphins and California Sea Lions—and trains animals to perform tasks such as ship and harbor protection, mine detection and clearance, and...

uses sea lions and dolphins, among other species, in the detection of seamines.

Plants

The mustard

Mustard plant

Mustards are several plant species in the genera Brassica and Sinapis whose small mustard seeds are used as a spice and, by grinding and mixing them with water, vinegar or other liquids, are turned into the condiment known as mustard or prepared mustard...

Arabidopsis thaliana
Arabidopsis thaliana
Arabidopsis thaliana is a small flowering plant native to Europe, Asia, and northwestern Africa. A spring annual with a relatively short life cycle, arabidopsis is popular as a model organism in plant biology and genetics...

, one of the best-studied plants in the world, normally turns red under harsh conditions. But using a combination of natural mutations and genetic manipulation, scientists from Danish biotechnology

Biotechnology

Biotechnology is a field of applied biology that involves the use of living organisms and bioprocesses in engineering, technology, medicine and other fields requiring bioproducts. Biotechnology also utilizes these products for manufacturing purpose...

company Aresa Biodetection, created a strain that only changes color in response to the nitrous oxide

Nitrous oxide

Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...

that leaks from landmines and other explosives. Because nitrous oxide can also be formed by denitrifying bacteria

Denitrifying bacteria

Denitrifying bacteria form a necessary part of the process known as denitrification as part of the nitrogen cycle, their primary purpose being to metabolise nitrogenous compounds, with the assistance of the nitrase reductase enzyme, to turn oxides back to nitrogen gas or nitrous oxides for energy...

, there is some risk of false positives using this technique, and researchers are attempting to make the plant less sensitive. The plants would aid demining by indicating the presence of mines through color change, and could either be sown from aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

or by people walking through demined corridors in minefields. As of February 2005, no studies have been conducted with actual landmines, though successful studies have been done in greenhouses. In order to prevent the spread of this genetically modified organism into the wild, the plants have been further modified so that they will only sprout when provided with an external growth factor.

Bacteria

A bacterium, known as a bioreporter

Bioreporter

Bioreporters are intact, living microbial cells that have been genetically engineered to produce a measurable signal in response to a specific chemical or physical agent in their environment. Bioreporters contain two essential genetic elements, a promoter gene and a reporter gene. The promoter...

, has been genetically engineered to fluoresce under ultraviolet light in the presence of TNT. Tests involving spraying such bacteria over a simulated minefield successfully located mines. In the field, this method could allow for searching hundreds of acres in a few hours, which is much faster than other techniques, and could be used on a variety of terrain types. While there are some false positives (especially near plants and water drainage), even three ounces of TNT were detectable using these bacteria. Unfortunately, there is no strain of bacteria capable of detecting RDX

RDX

RDX, an initialism for Research Department Explosive, is an explosive nitroamine widely used in military and industrial applications. It was developed as an explosive which was more powerful than TNT, and it saw wide use in WWII. RDX is also known as cyclonite, hexogen , and T4...

, another common explosive, and the bacteria may not be visible under desert conditions. Also, well-constructed munitions that have not had time to corrode may be undetectable using this method.

Nuclear detection

There are two principal techniques to detect land mines through nuclear reactions. Both rely on the use of neutron

Neutron

The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...

s.

The first such technique relies on the fact that the vast majority of explosives used in land mines are very nitrogen

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

rich when compared with other materials. To detect such anomalies one may make use of the nuclear reaction

¹⁴(n, γ)¹⁵N (10.8 MeV)

In practice a detection system using this reaction works by subjecting the mine to thermal neutrons while searching for the characteristic gamma ray emitted from the excited state in nitrogen-15; these photons will only be observed when an object containing nitrogen is being subjected to the neutron irradiation. One possible neutron source is californium

Californium

Californium is a radioactive metallic chemical element with the symbol Cf and atomic number 98. The element was first made in the laboratory in 1950 by bombarding curium with alpha particles at the University of California, Berkeley. It is the ninth member of the actinide series and was the...

-252 which undergoes spontaneous fission

Nuclear fission

In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...

. A better neutron source is to use a sealed tube electrostatic D-T neutron generation tube, this has the advantage that the tritium

Tritium

Tritium is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of protium contains one proton and no neutrons...

is much less radiotoxic than the californium so in the event of an accident such as an explosion, the nuclear mine detection equipment would pose a smaller threat to humans. This type of explosive detection has been proposed for use in airport security

Airport security

Airport security refers to the techniques and methods used in protecting airports and aircraft from crime.Large numbers of people pass through airports. This presents potential targets for terrorism and other forms of crime due to the number of people located in a particular location...

and for the detection of explosives in truck

Truck

A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...

s coming into military

Military

A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...

bases.

An alternative way of spotting land mines through nuclear reactions with the help of neutrons is that of measuring the thermalization of neutrons. In this technique the soil is irradiated by fast neutrons and the flux of thermal neutrons scattering back is measured. The motivation for this technique is that explosives contain much higher concentrations of hydrogen, which is a very effective moderator of neutrons.

Acoustic detection

It is possible to detect land mines by directing sound waves at the area to be demined, which causes the land mines to vibrate, and then using a laser to search for vibrations on the surface by means of the Doppler shift - this technique is termed Scanning Laser Doppler Vibrometry. Such devices have been constructed, e.g., at the University of Mississippi

University of Mississippi

The University of Mississippi, also known as Ole Miss, is a public, coeducational research university located in Oxford, Mississippi. Founded in 1844, the school is composed of the main campus in Oxford, four branch campuses located in Booneville, Grenada, Tupelo, and Southaven as well as the...

, at MIT and by the Kayser-Threde Company.

External links

Research and policy

Mines Advisory Group
Demining with Africa`s Sniffer Rats (APOPO)
European Commission action programme against antipersonnel landmines
EUDEM The European Union in humanitarian DEMining - technical research and development database
International Test and Evaluation Program for Humanitarian Demining
Humanitarian Demining Research at the University of Western Australia
University of Western Australia
The University of Western Australia was established by an Act of the Western Australian Parliament in February 1911, and began teaching students for the first time in 1913. It is the oldest university in the state of Western Australia and the only university in the state to be a member of the...
Demining with Hero Rats
Mineseeker Operations
Danish Demining Group
LOCOSTRA Modified Agricultural Technologies for Technical Survey that can be used for fostering agricultural development when demining is over

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Military mine clearance

Humanitarian demining

Current humanitarian demining methods

Manual detection with a metal detector

Dogs

Rats

Mechanical clearance

Personal protective equipment

Removal methods in demining

Removal methods in mine clearance

Case study

Detection methods under development

Ground penetrating radar

Dual-sensor

Honey bees

Mammals

Plants

Bacteria

Nuclear detection

Acoustic detection

See also

External links