A presentation on X-Ray applications in various fields .

A presentation on X-Ray applications in various fields like medical , lithography , spectroscopy , radiology , XRD etc

1. A PRESENTATION ON “ X-RAY APPLICATIONS IN VARIOUS FIELDS ” Presented by : Himanshu Dixit 16EUCNT600 CENTER OF NANOTECHNOLOGY, RTU KOTA

2. CONTENTS ELECTROMAGNETIC RADIATION SPECTRUM X-RAY CRYSTALLOGRAPHY X-RAY PHOTOELECTRON SPECTROSCOPY RADIOLOGY MAMMOGRAPHY AND CT SCAN DEXA – DUEL ENERGY X-RAY ABSORPTIOMETRY X-RAY DIFFRACTION POSITRON EMISSION TOMOGRAPHY (PET ) X-RAY LITHOGRAPHY

3. ELECTROMAGNETIC RADIATION SPECTRUM

4. X-RAY CRYSTALLOGRAPHY X-ray crystallography is a technique used for determining the atomic and molecular structure of a crystal, in which the crystalline atoms cause a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their disorder, and various other information.

5. Since many materials can form crystals—such as salts, metals, minerals, semiconductors, as well as various inorganic, organic, and biological molecules—X-ray crystallography has been fundamental in the development of many scientific fields. The method also revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. X-ray crystallography is still the chief method for characterizing the atomic structure of new materials and in discerning materials that appear similar by other experiments.

6. SOME CRYSTAL SYSTEMS

7. X-RAY PHOTOELECTRON SPECTROSCOPY (XPS) X-ray photoelectron spectroscopy is a surface sensitive quantitative spectroscopic technique that measures the elemental composition at the parts per thousand range, empirical formula, chemical state and electronic state of the elements that exist within a material. XPS spectra are obtained by irradiating a material with a beam of X-rays while simultaneously measuring the kinetic energy and number of electrons that escape from the top 0 to 10 nm of the material being analyzed. XPS requires high vacuum (P ~ 10 −8 milli bar) or ultrahigh vacuum (UHV; P < 10 −9 milli bar) conditions, although a current area of development is ambient pressure XPS, in which samples are analyzed at pressures of a few tens of milli bar. XPS is a surface chemical analysis technique that can be used to analyze the surface chemistry of a material in its as received state, or after some treatment.

8. XPS is also known as ESCA (Electron Spectroscopy for Chemical Analysis), an abbreviation introduced by Kai Siegbahn's research group to emphasize the chemical information that the technique provides. In principle XPS detects all elements. In practice, using typical laboratory scale X-ray sources, XPS detects all elements with an atomic number ( Z ) of 3 (lithium) and above. It cannot easily detect hydrogen ( Z = 1) or helium ( Z = 2). Detection limits for most of the elements are in the parts per thousand ranges. Detection limits of parts per million (ppm) are possible, but require special conditions: concentration at top surface or very long collection time. XPS is routinely used to analyze inorganic compounds, metal alloys, semiconductors, polymers, elements, catalysts, glasses, ceramics, paints, papers, inks, woods, plant parts, makeup, teeth, bones, medical implants, biomaterials, viscous oils, glues, ion modified Materials and many others.

9. 10 RADIOLOGY Radiology is a specialty that uses medical imaging to diagnose and treat diseases seen within the body. A variety of imaging techniques such as X-ray radiography, ultrasound, computed tomography ( CT) and magnetic resonance imaging (MRI) are used to diagnose and/or treat diseases. The following procedures are currently widely available: Central Nervous System: Brain , Spine Cardiovascular System: heart, blood vessels Musculoskeletal System: bone, muscles, and joints Digestive, Urinary, and Respiratory System: intestines, kidneys, liver, stomach, lungs Reproductive System and Mammography: male and female reproductive organs and breasts

10. 11 X-RAY IMAGING Other imaging techniques: Ultrasound - images due to speed of amounts of sound energy Magnetic resonance – based on magnetic properties Elastography - shows strain levels in tissue produced in response to small external applied compressions Absorption of X-ray and gamma-ray by different material for image: today, 2-dimensional solid state detectors are used in place of films for X-ray and gamma-ray imaging as shown in this image.

11. 12 MAMMOGRAPHY AND CT SCAN X-rays provide the sharpest images of the breast's inner structure. Mammogram detects small tumours and changes in the breast tissues . Computed tomography (CT), scanner takes images by rotating an x-ray tube around the body while measuring the constantly changing absorption of the x-ray beam by different tissues in your body. The sensitive scanner provides small differences in absorption of the beam by various tissues. The information is fed into a computer which reconstruct images of thin cross sections of the body.

12. 13 DEXA – DUEL ENERGY X-RAY ABSORPTIOMETRY Dual energy X-ray absorptiometry (DEXA) is also called dual x-ray absorptiometry (DXA). A high and a low energy x-ray beams pass through the bone and the difference in absorption is used to estimate the bone mineral density. Bone mineral density (BMD) is an indication of bone mass. BMD generally correlates with bone strength and its ability to bear weight. Low BMS is osteoporosis with risk of easy bone fracture.

13. 14 IMPACT OF X-RAY DIFFRACTION Using X-ray diffraction, nearly all structure of compounds artificially made or isolated from nature have been determined, including structures of semiconductors, DNA molecules, and proteins. Structure data banks serve science, technologies, and medicine This is one of the diffraction X-ray tubes with beryllium windows by Varian, operating at 60 keV , 1500 - 2000 wats , target W, Mo, Cr ($ 3000 each ).

14. 15 X-RAY DIFFRACTION RESULTS Two X-ray diffraction patterns are shown here : Top : diffraction pattern from Al-wire recorded on a film revealing preferred orientation and size of micro-crystals in the wire . Bottom : X-ray diffraction pattern of a single crystal showing positive image of X-ray beams. Intensities of these beams allows us to determine molecular and crystal structures. Various data banks of structures are now available for research and development.

15. 16 POSITRON EMISSION TOMOGRAPHY (PET) Positron emission tomography is a nuclear medicine functional imaging technique that is used to observe metabolic processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide which is introduced into the body on a biologically active molecule. In modern PET-CT scanners, three dimensional imaging is often accomplished with the aid of a CT X-ray scan performed on the patient during the same session, in the same machine. The function of the organs provides better diagnosis than CT .

16. X-Rays-Medical Applications X-rays are used in medicine for medical analysis. Dentists use them to find complications, cavities and impacted teeth. Soft body tissue are transparent to the waves. Bones and teeth block the rays and show up as white on the black background

17. Below are some x-rays showing objects which have been swallowed by people. The examples show an open safety pin and a child's stomach with all the pieces of a magnetic toy re-aligned after he's swallowed them one by one.

18. X-rays having wavelengths of 0.04nm to 0.5nm represent another radiation source for high-resolution design reproduction. X-ray lithography was first demonstrated to obtain high-resolution designs using X-ray proximity printing by Spears and Smith. X-ray lithography can be extended optical resolution of 15 nm. ESSENTIAL ELEMENTS IN X-RAY LITHOGRAPHY A mask consisting of a pattern made with an X-ray absorbing material on a thin X-ray transparent membrane. An X-ray source of sufficient brightness. An X-ray sensitive resist material. X-RAY LITHOGRAPHY

19. The X-rays are typically from synchrotron radiation source, allowing rapid exposure . X-ray lithography is expensive, because of the expense of operating a synchrotron. The actual operating expenses without considering the initial investment of tens-of-millions of dollars. Therefore, the LIGA process was developed to reduce the dependency on a synchrotron . LIGA is a German acronym for Lithographie , Galvanoformung , Abformung (Lithography, Electroplating, and Molding ) that describes a fabrication technology used to create high-aspect-ratio microstructures. X-RAY LITHOGRAPHY CONT.

20. Short wavelength from X-rays 0.4-4 nm No diffraction effect Simple to use U niform refraction pattern High resolution for small feature size ADVANTAGES OF X-RAY LITHOGRAPHY DISADVANTAGES OF X-RAY LITHOGRAPHY Distortion in absorber Masks are expensive to produce

21. X-ray lithography is primarily used in nanolithography 15 nm optical resolution Utilizes short wavelength of 1 nm Requires no lenses Allows for small feature size APPLICATION OF X-RAY LITHOGRAPHY

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