Tungsten Alloy Shielding for X-Ray

Tungsten Alloy Shielding for X-Ray

Tungsten alloy X-ray shielding is available in a variety of configurations, including standard cabinets and lead rooms as well as custom designs suitable for parts inspections, automatic defect recognition, materials research and biological irradiation. Chinatungsten provides X-ray systems and tungsten alloy X-ray shielding irradiator systems for instrument and dosimetry calibration.

Tungsten Heavy Alloy X-ray Detector

Tungsten Heavy Alloy X-ray Detector

Chinatungsten can offer tungsten heavy alloy X-ray detectors, which is based on an innovative sensor designing that makes possible unprecedented speed and superior image quality.

X-ray detectors are suitable for a range of applications including mammography and tomosynthesis, breast CT, dental CBCT, fluoroscopy, cardiology and angiographic imaging, bone densitometry, scientific instrumentation and non-destructive testing.
Key Features:

    High Speed: 26 – 86 fps

    High resolution: 75 - 300 µm pixel pitch

    Superior image quality: high DQE 0.7 at 0.5 lp/mm, high contrast, high dynamic range

    Reduced image lag

    Fiber optic plate increases lifetime and improves DQE

    Ready-to-run software and drivers

    Flexible, reliable, stable and robust

Tungsten Alloy Military: Applications of tungsten alloy sphere for military...

Tungsten Alloy Military: Applications of tungsten alloy sphere for military...: Tungsten alloy sphere can be also used as bullets or pellets in many military filed. These are the pellets from inside a shotgun shell...

Standards for Tungsten Radiation Shielding

Standards for Tungsten Radiation Shielding

Here is standards for tungsten radiation shielding material:

cifications		Grades
		Thin-Magnetic				Non-Magnetic
		AGH-1	AGH-2	AGH-3	AGH-4	AGH-1	AGH-2	AGH-3
Tungsten Content	Wt%	90	92.5	95	97	90	92.5	95
Nominal Density	g/cc	17	17.5	18	18.5	17	17.5	18
Standard SAE-AMS-T-21014		Class1	Class2	Class3	Class4	Class1	Class2	Class3
Standard ASTM-B-777-87		Class1	Class2	Class3	Class4	Class1	Class2	Class3

Tungsten Metal for Shielding

 Tungsten Metal for Shielding
Tungsten metal is a grayish-white lustrous metal that is often brittle and hard to work. Of all metals in pure form, tungsten has highest melting point of all elements except carbon - vary between 3387°C and 3422°C. It also has good thermal and electrical conductivity. Its electrical conductivity at 0°C is about 28% of that of silver which itself has the highest conductivity of all metals. In addition, it has low vapor pressure at high temperatures. Such properties make tungsten metal a high performance material in high temperature products and processes. Tungsten metal powder is used as a filler material in plastic composites, which are used as a nontoxic substitute for lead in bullets, shot, and radiation shields.IF you need tungsten metail shielding, you could contact sales@chinatungste.com.

Specification for Tungsten Alloy Shielding Powder

Specification for Tungsten Alloy Shielding Powder

Specification

Item No.	Purity	Average Particle Size (APS)
PW74-P1	≥99.95%(metal basis)	1-1.5 µm
PW74-P2	≥99.95%(metal basis)	1.5-2 µm
PW74-P3	≥99.95%(metal basis)	2-4 µm
PW74-P4	≥99.95%(metal basis)	4-6 µm
PW74-P5	≥99.95%(metal basis)	6-10 µm
PW74-P6	≥99.9%(metal basis)	>75 mm (+200 mesh)
PW74-P7	≥99.3%(metal basis)	between 100 and 200 Mesh

Tungsten Alloy Powder for Radiation Shielding

 Tungsten Alloy Powder for  Radiation Shielding

High density, spheroidal tungsten powder

Appearance:

Gray metallic powder

Physical Properties:

Particle Size: Minimum 85% > 70 Microns
Particle Size Distribution: Minimum 90% between 100 and 200 Mesh
Bulk Density: Minimum 18.50 g/cc (Helium Pycnometer)
Tap Density: Minimum 11.90 g/cc (ASTM B527)

X-Ray Shielding Design & Engineering

X-Ray Shielding Design & Engineering

Chinatungsten offers a broad line of radiation shielding for many applications including shipping casks, gamma shielding, and X-ray shielding for non-destructive testing.  Chinatungsten has over 20years of experience designing radiation shielding.  They offer engineering analysis of radiation shielding requirements to design optimum shielding.  

Tungsten Powder for Radiation Shielding

 Tungsten Powder for Radiation Shielding

Tungsten powders are widely used in the production of weight fillers, radiation shielding fillers, and induction accelerators etc. Thin film surface of its polymer mixture are ideally suited for radiation protection. The large particles make it ideal heavy metal filler for injection-molding applications. The unique shape and resulting high flow ability of these particles make it suitable for metal spray industry applications. 

Appearance:

Gray metallic powder

Physical Properties:

Particle Size: Minimum 85% > 70 Microns
Particle Size Distribution: Minimum 90% between 100 and 200 Mesh
Bulk Density: Minimum 18.50 g/cc (Helium Pycnometer)
Tap Density: Minimum 11.90 g/cc (ASTM B527)

Tungsten Heavy Alloy Shielding is Much Better Than Lead

Tungsten heavy alloy shielding is much better than lead

How X-rays are Created

X-rays are created by bombarding a tungsten target with electrons inside a device known as the x-ray tube. To generate this stream of electrons inside the x-ray tube, a powerful x-ray generator first takes the regular alternating current (AC) electricity from the power line at about 120 to 480 volts and transforms it into power in the range of 35 to 150 kilo volts (kV or thousands of volts). When this very high voltage potential is applied to the x-ray tube, a tight beam of electrons is fired out of a small wire (called the cathode) and strikes a metal disk (called the anode). When this stream of electrons hits the special metal compound of the anode (often tungsten or alloys including tungsten), it causes x-ray energy to be released from the metal's atomic structure. These x-rays are often filtered and collimated (or focused) as they leave the x-ray tube. The rays pass through the body part of interest in a straight line and are then recorded onto film or captured by an image intensifier and TV system to make the final image.
X-ray tubes are precision designed and manufactured and have evolved tremendously over the past 100 years. X-ray tubes are often the most expensive component in an x-ray system and can cost more than $50,000 each (for the ones used in high speed CT scanners or cardiac catheterization labs). The x-ray tube is a glass or metal envelope with a vacuum seal inside. X-ray tubes create tremendous heat while the beam of electrons is bombarding the cathode to produce the x-ray. Like a light bulb, an x-ray tube requires replacement up to a few times per year, depending on use.

sten Alloy X-ray Tube in Various Generations of CT-3

Sampling Geometries of the beam: The sampling geometry of the beam in CT scanners along the different generations can be described as three configurations: Further advances: Another limiting factor in image acquisition was tungsten alloy X-ray tube. The need for long, high intensity exposures and very stable output placed enormous demands on:

Further advances: Another limiting factor in image acquisition was tungsten alloy X-ray tube. The need for long, high intensity exposures and very stable output placed enormous demands on both the tube and generator (power supply). Very high performance rotating anode tubes were developed to keep up with demand for faster imaging, as were the regulated 150 kV switched mode power supplies to drive them. Modern systems have power ratings up to 100 kW.

Tungsten Alloy X-ray Tube in Various Generations of CT-2

Fourth generation of CT scanner uses Rotate-Fixed Ring geometry where a ring of fixed detectors completely surrounds the patient. Tungsten alloy X-ray tube rotates inside the detector ring through a full 360 degrees with a wide fan beam producing a single image. Due to the elimination of translate-rotate motion the scan time is reduced comparable with third generation scanner, initially, to 10 seconds per slice but the radiographic geometry is poor because the X-ray tube must be closer to the patient than the detectors, i.e. the geometric magnification is large also scatter artifact is more than third generation since they cannot use anti-scatter grid. -The disadvantages of poor geometry noted above have been alleviated very neatly by the so called nutating geometry. Tungsten alloy X-ray tube is external to the detector ring but slightly out of the detector plane, this change resulted in increasing both the acquisition speed, and image resolution. The method of scanning was still slow, because the X-ray tube and control components interfaced by cable, limiting the scan frame rotation. Further, they were more sensitive to artifacts because the non-fixed relationship to the x-ray source made it impossible to reject scattered radiation.

Tungsten Alloy X-ray Tube in Various Generations of CT

First generation: CT scanners used a pencil-thin beam of radiation. The images were acquired by a "translate-rotate" method in which the x-ray source and the detector in a fixed relative position move across the patient followed by a rotation of the x-ray source/detector combination (gantry) by 1° for 180°. , The thickness of the slice, typically 1 to 10mm, is generally defined by pre-patient collimation using motor driven adjustable wedges external to tungsten alloy X-ray tube.

 

Second generation: The x-ray source changed from the pencil-thin beam to a fan shaped beam. The "translate-rotate" method was still used but there was a significant decrease in scanning time. Rotation was increased from one degree to thirty degrees. Because rotating anode tubes could not withstand the wear and tear of rotate-translate motion, this early design required a relatively low output stationary anode x-ray tube. The power limits of stationary anodes for efficient heat dissipation were improved somewhat with the use of asymmetrical focal spots (smaller in the scan plane than in the z-axis direction), but this resulted in higher radiation doses due to poor beam restriction to the scan plane. Nevertheless, these scanners required slower scan speeds to obtain adequate x-ray flux at the detectors when scanning thicker patients or body parts.

Third generation: Designers realized that if a pure rotational scanning motion could be used rather than the slam-bang translational motion, then it would be possible to use higherpower (output), rotating anode x-ray tubes and thus improve scan speeds in thicker body parts in which the 3rd generation become a Rotate-Rotate geometry. A typical machine employs a large fan beam such that the patient is completely encompassed by the fan, the detector elements are aligned along the arc of a circle centered on the focus of the X-ray tube. The X-ray tube and detector array rotate as one through 360 degrees, different projections are obtained during rotation by pulsing the x-ray source, and bow-tie shaped filters are chosen to suit the body or head shape by some manufacturers to control excessive variations in signal strength. Such filters generally attenuate the peripheral part of the divergent fan beam to a greater extent than the central part. It also helps overcome the effects of beam hardening and to minimize patient skin dose in the peripheral part of the field of view -A number of variants on this geometry have been developed, which include those based on offsetting the centre of rotation and the use of a flying focus tungsten alloy  X-ray tube.

 

Design of CT scanner for Tungsten Alloy Tube

The CAT scanner is made up of three primary systems, including the gantry, the computer, and the operating console. Each of these is composed of various subcomponents. The gantry assembly is the largest of these systems. It is made up of all the equipment related to the patient, including the patient support, the positioning couch, the mechanical supports, and the scanner housing. It also contains the heart of the CAT scanner, tungstenalloy x-ray tube, as well as detectors that generate and detect x- rays.

History of Tungsten Alloy X-ray Tube

William Roentgen, who discovered x rays in 1895. Around this time, various scientists were investigating the movement of electrons through a glass apparatus known as a Crookes tube. Roentgen wanted to visually capture the action of the electrons, so he wrapped his Crookes tube in black photographic paper. When he ran his experiment, he noticed that a plate coated with a fluorescent material, which just happened to be lying nearby the tube, fluoresced or glowed. This was unexpected because no visible light was being emitted from the wrapped tube. Upon further investigation, he found that indeed there was some kind of invisible light produced by this tungsten alloy tube, and it could penetrate materials such as wood, aluminum, or human skin.

Electron Beam Scanner and Tungsten Target

The electron beam gun is a triode system operated with a small-size tungsten bolt cathode that is indirectly heated by electron bombardment. The Wehnelt electrode and the anode are shaped as a Rogowski transducer with a bell-shaped through-hole anode. This configuration has been chosen since it greatly reduces the dependence of focal spot size on electron beam current. The electron beam gun is operated at about 10−6 mbar gas pressure which is provided by a vacuum pump system, consisting of a scroll pre-pump and a turbo molecular main pump operated in series. The gas pressure in the beam column and the scanner head is somewhat higher in the range of 10−5 mbar.

How tungsten alloy CT target work with radiation

There are a few other notable approaches to fast tomography using x-rays or gamma rays. Since all of the above-mentioned approaches have numerous drawbacks and limitations regarding multiphase flow tomography, it was decided to design and build up a dedicated electron beam x-ray CT scanner for this application. The decision for an electron beam type CT and against a CT with stationary gated sources was due to several reasons. First, electron beam technology provides excellent versatility since the electron beam can be almost arbitrarily steered and shaped as needed. In the simplest case the electron beam will be swept along a semicircular target as in medical electron beam CT to generate projection data from a single plane. Moreover, subsequent sweeping on different circular paths on the target enables multi-slice CT as well as velocity measurement for two-phase flows. Additional beam optics can be provided to shape the focal spot as required and to adjust the beam focus when scanning at different axial positions (planes). Only one beam power supply is required. Another strong argument is the straightforward upgrade capability towards higher x-ray energy by introduction of high-energy electron beam generators or superconducting accelerators. Therefore, tungsten alloy material will have advantage in this case. 

Hamilton Vial Heating Shield

Made from Tungsten, this Hamilton Vial Heating Shield holds vials the size of 2.65cm in width. Fits within standard aluminum heat blocks. Easy button top and vial cut to lift vials 

Tungsten Alloy Medical CT Radiation

Scanned electron beam x-ray tomography is therefore a promising technology. Instead of mechanical rotation of scanner components, an electron beam is rapidly swept across an x-ray target using deflection coils. This technology was introduced in medicine more than two decades ago where it is mainly being used for cardiovascular diagnostics. Tungsten Alloy material is a good choice for medical CT and X-ray radiation protection.

Tungsten Alloy CT Target

Tungsten alloy X-ray CT target as an imaging modality is highly advantage due to its non-intrusiveness and its ability to penetrate opaque wall materials. One essential disadvantage of existing CT system is the requirement for rotating components. To measure multiphase flows in a velocity range of one meter per second or more, frame rates of at least 1000 frames per second are required to produce sharp phase distribution images with a spatial resolution of about one millimeter. To achieve this, mechanically rotating parts are to be avoided. 

Why Use Tungsten Alloy Shielding?

Similar to lead (Pb), tungsten possesses a high density (19.25g/cc) and plizbility in its metal state. Where tungsten gains the advantage is in the ease of blending into plastic for extrusion or molding into custom shapes and sizes. Tungsten also differd from lead in that it is virtually non-reactive and is non-toxic. This eases handling requirements and minimizes issues associated with lead use such as long-term disposal and the potential characterization as a mixed hazardous waste.
Tungsten alloy also exists in sufficient, available quantities as to be a viable shielding material and, while more expensive than lead or steel, the cost differences are not prohibitive.

Tungsten Alloy Shielding Better than Lead Protection?-1

The most effective utilization of tungsten, in one of its many forms, will be achieved after evaluation of several key factors (space/environmental sonsiferations, long-term storage/disposal, and potential for multiple applications) on the prospective application. Though not cost-beneficial for "ordinary" shielding applications, when properly selected as the shielding material, dose avoidance exceeding that of lead will be achieved.

Advantages of Tungsten Alloy Cube for Military Application

We can produce all kinds of tungsten alloy cubes and we can design tungsten alloy cube which could be manufactured as the parts of military defense,tungsten alloy cubes for military is widely used in extrusion die, some counterweights, such as yacht counterweights, vehicle counterweights, airplane counterweights, helicopter counterweights, boat counterweights, tank counterweights, etc.

Why we adopt tungsten alloy cube for parts of extrusion die instead of lead or aluminum or other materials' block? Because tungsten alloy has high melting point more than ten times higher than lead, which is important in extrusion die process. Then, tungsten alloy has high Mohs hardness. What is the most important reason is that tungsten alloy is environment friendly, which lead can not reach.

Since at least World War II, tungsten alloys have proven their worth in ordnance applications. Hyper-velocity armor-penetrating applications use our materials in balls, cubes, and projectile shapes. Manufacturing techniques and additives allow us to vary certain properties, such as elongation, ultimate tensile strength, and hardness, of our tungsten alloys in order to meet your needs.

Tungsten Combustion Chamber of Turbo Engines

Conventional combustion chambers are generally of optimized rating for take-off or near take-off operation. This signifies that, in the primary zone of the combustion chamber, a fraction of the air flow of the compressor is introduced so that, with the injected fuel, the fuel-air mixture in this zone would be essentially stoichiometric in turbo engines. Under these conditions, due to the levels of temperature and high pressures, as complete as possible a combustion is obtained, combustion yields greater than 0.99 are attained, the speeds of the chemical reaction being optimum for these stoichimoetric mixtures. 

In addition, the pressures and temperatures at the outlet of the compressor are lower; the result is that the chamber, with the partial charge is very much maladjusted and that the slow speed combustion efficiency rarely goes beyond 0.93. The combustion is, therefore, very incomplete, which means much higher concentrations of carbon monoxide and unburnt residues at the exhaust than under normal operation. The proportions of the pollutants are all the higher, the lower the total yield of the combustion. 

The fresh gas/burnt gas mixture must also be advantageous because it contributes to the increase in the temperature of the carburized mixture and, therefore, aids in its atomization and consequently permits an improvement in the speed of the chemical reaction. In conventionally allowing this contact of the carburized mixture with the high temperature gas from the combustion it is desirable to arrange for a recirculation of the latter by searching for a convenient turbulence level.

All of these solutions, which allow an improvement in the combustion yield have, however, a maximum efficiency only for values sufficient for the pressures and temperatures of the air at the chamber inlet.

Tungsten Alloy Advantages

There are some main properties for tungsten heavy alloy as follows:

-High Density: high density between 16.5 and 18.6 g/cc with tungsten content from 80%W to 97%W.

-High Melting Point: the highest melting point as 3,422 C, 6,192 F and the highest tensile strength. -Excellent Hardness: almost from 24 HRC to 36 HRC, or even above 40 HRC through swaging.

- Superior Wearing Resistance: excellent wearing resistance in high concentrations of CO2、H2S、Cl- corrosion environments.

-High Ultimate Tensile Strength: excellent properties almost for products used in military or other high-tech filed.

-High Temperature Resistance: optimum parameters had been obtained as bonding temperature 1403K, bonding time 50min, bonding pressure 7.5MPa and cooling velocity 5K/min

-Non-toxic and Environmental Friendly: compared with lead, tungsten heavy alloy is an ideal, environmentally friendly, and is of non-toxic.

-Good Corrosion Resistance: corrosion resistance sulfur jar mandrel; stuffing box and other products，whose corrosion-resistant and wear-resistance have reached the international advanced level.

-Well Machinability: relatively easy to machine, and can be plated or painted to enhance their corrosion protection.

-High Radiation Adsorption Capability: At the same weights high density alloy can provide the same energy absorption as lead using 1/3 less material.

-High Impact Resistance and Crack Resistance: It is defined as the amount of energy per volume that a material can absorb before rupturing.