X-Ray Windows Product Line February 3, 2010

Windows Product Line X-Ray Windows Common Methods Located between the sample and the detector Detector is usually under vacuum and possibly cooled to increase sensitivity In EDS (energy dispersive spectroscopy) high energy particles (electrons or protons) are focused on a sample causing an electron to be ejected from a shell. When an electron from a higher energy level fills the hole, an X-Ray is produced at an energy specific to that shell level and element X-Rays pass through a “window” to a detector to identify the material or elements present in the material by measuring the X-Ray intensity at various energies Common Methods XRF EDXRF WDXRF XRD X-rays from about 0.12 to 12 keV (10 to 0.10 nm wavelength) are classified as "soft" X-rays, and from about 12 to 120 keV (0.10 to 0.01 nm wavelength) as "hard" X-rays, due to their penetrating abilities. Hard X-rays can penetrate solid objects, and their most common use is to take images of the inside of objects in diagnostic radiography and crystallography. By contrast, soft X-rays can hardly be said to penetrate matter at all; for instance, the attenuation length of 600 eV (~ 2 nm) x-rays in water is less than 1 micrometer.[3] X-rays are emitted by electrons outside the nucleus. EDS- To stimulate the emission of characteristic X-rays from a specimen, a high-energy beam of charged particles such as electrons or protons (see PIXE), or a beam of X-rays, is focused into the sample being studied. At rest, an atom within the sample contains ground state (or unexcited) electrons in discrete energy levels or electron shells bound to the nucleus. The incident beam may excite an electron in an inner shell, ejecting it from the shell while creating an electron hole where the electron was. An electron from an outer, higher-energy shell then fills the hole, and the difference in energy between the higher-energy shell and the lower energy shell may be released in the form of an X-ray. The number and energy of the X-rays emitted from a specimen can be measured by an energy-dispersive spectrometer. As the energy of the X-rays are characteristic of the difference in energy between the two shells, and of the atomic structure of the element from which they were emitted, this allows the elemental composition of the specimen to be measured. X-ray fluorescence (XRF) is the emission of characteristic "secondary" (or fluorescent) X-rays from a material that has been excited by bombarding with high-energy X-rays or gamma rays. The phenomenon is widely used for elemental analysis and chemical analysis, particularly in the investigation of metals, glass, ceramics and building materials, and for research in geochemistry, forensic science and archaeology. XRF -When materials are exposed to short-wavelength X-rays or to gamma rays, ionisation of their component atoms may take place. Ionisation consists of the ejection of one or more electrons from the atom, and may take place if the atom is exposed to radiation with an energy greater than its ionisation potential. X-rays and gamma rays can be energetic enough to expel tightly held electrons from the inner orbitals of the atom. The removal of an electron in this way renders the electronic structure of the atom unstable, and electrons in higher orbitals "fall" into the lower orbital to fill the hole left behind. In falling, energy is released in the form of a photon, the energy of which is equal to the energy difference of the two orbitals involved. Thus, the material emits radiation, which has energy characteristic of the atoms present. The term fluorescence is applied to phenomena in which the absorption of radiation of a specific energy results in the re-emission of radiation of a different energy (generally lower). WDXRF- The Wavelength dispersive X-ray spectroscopy (WDXRF or WDS) is a method used to count the number of X-rays of a specific wavelength diffracted by a crystal. The wavelength of the impinging x-ray and the crystal's lattice spacings are related by Bragg's law and produce constructive interference if they fit the criteria of Bragg's law. Unlike the related technique of Energy dispersive X-ray spectroscopy (EDS) WDS reads or counts only the x-rays of a single wavelength, not producing a broad spectrum of wavelengths or energies. This generally means that the element must be known to find a crystal capable of diffracting it properly. The technique is often used in conjunction with EDS, where the general chemical make-up of an unknown can be learned from its entire spectrum. WDS is mainly used in chemical analysis, in an X-ray fluorescence spectrometer, or in an electron microprobe. XRD - X-ray Diffraction (XRD) is a powerful nondestructive technique for characterizing crystalline materials. It provides information on structures, phases, preferred crystal orientations (texture), and other structural parameters, such as average grain size, crystallinity, strain, and crystal defects. X-ray diffraction peaks are produced by constructive interference of a monochromatic beam of x-rays scattered at specific angles from each set of lattice planes in a sample. The peak intensities are determined by the atomic decoration within the lattice planes. Consequently, the x-ray diffraction pattern is the fingerprint of periodic atomic arrangements in a given material. An online search of a standard database for x-ray powder diffraction patterns enables quick phase identification for a large variety of crystalline samples.

Windows Product Line DuraBeryllium High purity beryllium window and a thin layer of DuraCoat®. DuraCoat is a low-Z material creates a hermetic, corrosion resistant window that is used for ultra-high vacuum x-ray applications AP3 Ultra-thin Polymer X-ray Windows The highest performing x-ray windows available for low energy x-ray analysis. High x-ray transmission of light element energies AP3 Windows are composed of ultra-thin layers of Moxtek polymer, DuraCoat®, and aluminum. AP3 Windows are supported by a rigid silicon grid with 77% open area ProLINE polymer windows Used in wavelength dispersive spectrometers and proportional counters ProLINE Series windows are the thinnest WDXRF windows manufactured by Moxtek® and these windows outperform stretched polypropylene and other commonly used windows. Hermetic - implies being impervious to air or gas.

DuraBeryllium Products Line High purity beryllium window with optional coatings for moisture and corrosion resistance. Windows as thin as 8 μm provide highest available transmission for beryllium windows. Coating provides corrosion protection. Attachment by epoxy adhesive (polymeric) or metal diffusion bond. Feature Strong, thin (8um) DuraCoat® Vacuum Tight to better than 3x10-10 mbar L/sec of helium Uniform Thickness DuraCoat®Plus coating Metal seal Epoxy adhesive mounting Benefit High transmission of low energies Resistant to 85% humidity, chemicals, hermetic seal No gas diffusion, higher resolution, better light element detection. Uniform transmission Highly resistant to water (>3 mos. immersion) and some chemicals. High temperature bake-out possible Lower cost for small orders; not suitable for high temp bake-out

DuraCoat®Plus Feature Benefits DuraCoat®Plus uses the standard DuraCoat and an additional polymer film both of which Moxtek has used with great success for over 20 years. The combination of these two films on beryllium foils results in an extremely robust product, delivering exceptional value and performance. Feature DuraCoat®Plus coating Benefits Water corrosion protection Beryllium windows can be used in moisture condensing applications Transmission performance is similar to DuraBeryllium. Chemical resistance protection (see datasheet)

DuraBeryllium Products Specifications Description   Uncoated (adhesive bonded) Coated with DuraCoat® (Metal Diffusion bonded) Coated with DuraCoat®Plus (Metal Diffusion bonded)* Beryllium Thickness (with tolerance) 8µm (+5/-0) 12µm (+5/-0) 25µm (+5/-2) 50µm (± 10%) 125µm (± 10%) 250µm (± 10%) Window Diameter (nominal)** 9.2 mm 12.0 mm 16.0 mm Maximum Operating Temperature 110°C 550°C 400°C **Other diameters available on special order. Special orders increase cost and delivery is longer. indicates a standard part (lower cost)

DuraBeryllium Products Mount, Transmission Effect of coating

DuraBeryllium Products Application Microanalysis EDXRF WDXRF XRD

Mount Criteria Important: Moxtek standard mount should always be offered. Custom mounts are more expensive and longer lead time. Minimum Foil Thickness for Maximum Opening

AP3 Ultra-Thin Windows Products Line AP3 Ultra-thin Polymer X-ray Windows are our highest performing x-ray windows available for low energy x-ray analysis. Ideal for applications that require high x-ray transmission of light element energies, light rejection, vacuum tightness, and reliability. Feature Ultra-thin polymer window Silicon support structure UV, IR, & visible light rejection DuraCoat® Uniform thickness High purity Benefit High transmission of low energies High mechanical strength, durable Low detector noise Chemical, moisture resistant, hermetic seal Uniform transmission Low spectral contamination

AP3 Ultra-Thin Windows Products Line AP3 Windows are composed of ultra-thin layers of Moxtek polymer, DuraCoat®, and aluminum. Proprietary Moxtek DuraCoat treatment enables the AP3 window to withstand hostile environments. DuraCoat provides corrosion resistance, and humidity resistance up to 85% RH. AP3 Windows support Rigid silicon grid with 77% open area. Patented window design enables the window to withstand over 1.3 atmospheres of differential pressure. Burst pressure is typically > 60 psi. AP3 Windows pressure cycling >100,000 cycles at a differential pressure of 1.2 atm without degradation in window performance. AP3.3 Windows are used in applications that require the highest transmission of low energy x-rays. AP3.7 Windows are used in applications where maximum light element sensitivity is not required. Both of these windows are used in applications where conventional beryllium windows are ineffective.

AP3 Ultra-Thin Windows Products Line Silicon support grid Provides support X-rays pass between ribs 77% open area with wide rib spacing Solid Angle maximized at close distance to sample Silicon Support Grid

AP3 Ultra-Thin Windows Products Line Transmission Specifications

AP3 Ultra-thin Windows Application X-ray Detectors Si(Li) Detectors Si-PIN Detectors Silicon Drift Detectors (SDD)

Pro-Line Series Windows Thinnest windows made by Moxtek. Uses ultra-thin polymer. ProLine 10 is low cost, high transmission window for applications not requiring high vacuum. ProLine 20 is low cost, high transmission with a support grid for vacuum applications. ProLine 30 is a large area, vacuum tight window for proportional counters. Features Benefits Ultra-thin polymer window Mechanically strong Large open area Charge dissipation Uniform thickness High material purity High transmission of low energies Long window life Large detection area Low detector noise Uniform transmission Low spectral contamination

ProLine Series Product Detail Window Composition Composed of an ultra-thin layer of Moxtek® polymer and a charge dissipative layer of aluminum attached to a thin metal frame. Window frames may be provided by a customer or by Moxtek. Vacuum Tightness Leak rate of less than 1 x 10-3 mbar L/sec He. Mechanical Strength ProLINE Series 10 windows are more than 4 times stronger than polypropylene windows. ProLINE Series 20 windows are supported by a strong metal support grid. ProLINE Series 20 windows have withstood hundreds of cycles at a differential pressure of 1.2 atm without degradation in window performance. Charge Dissipation Can be coated with 200 angstroms of aluminum for charge dissipation.

PoLine Series Application WDXRF Systems Flow Proportional Counters Microanalysis Column separation windows Detector Arrays Electron windows Ideal for applications that require high transmission of low energy x-rays. Analysis of B(Kα) is possible with this window See transmission curve

ProLine Series Product Transmission

Window Comparison Reference General Window Information Product Name AP3.3 AP3.7 ProLINE 10 ProLINE 20 ProLINE 30 DuraBeryllium Window Material Polymer Beryllium Light tight Yes No Yes (if Al coated) Open Area 77% 100% 76% 75-85% (grid design) Vacuum tight, mbar*l/s 5x10-10 1x10-3 1x10-7 <1x10-10 Max temp, °C 70 40 85-550 Support Material Silicon N/A Metal Mounting Adhesive Epoxy or Diffusion Metal bond Table is for comparison purposes only. Please refer to product datasheet for latest, most accurate information.

Window type needed to detect element Elements detectable with beryllium or AP3 window Elements detectable with AP3 polymer window