the y-coordinate is calculated from the following equation due to the position independence of the anode pulses: (12) For transformation of the (x, y) information into scattering angle ϕ a removable calibration mask in front of the entrance window is used. This mask allows correction for x and y distortions too. For notation detail, the cathode has an ion drift time on the order of a few ms. To prevent ion saturation of the detector, a limit of 1 kHz must be applied to the number of particles entering the detector. Instrumentation Elastic Recoil Detection Analysis was originally developed for hydrogen detection or a light element (H, He, Li, C, O, Mg, K) profiling with an absorber foil in front of the energy detector for beam suppression. Using an absorber foil prevents the higher energy ion beam from striking the detector and causing degradation. Absorber foils increase the lifetime of the detector. More advanced techniques have been implemented to negate the use of absorber foils and the associated difficulties that arise through the use of it. In most cases, medium heavy ion beams, typically 36Cl ions, have been used for ERDA so far with energies around 30 MeV. Depth resolution and element profiling of thin films has been greatly advanced using elastic recoil detection analysis. Figure 2, on the left, depicts the interaction of a heavy ion beam striking the sample atoms and the resulting backscattering and recoil ions. Ion source and interactions Particle accelerators, such as a magnetron or cyclotron, implement electromagnetic fields to achieve acceleration of elements. Atoms must be electrically charged (ionized) before they can be accelerated. Ionization involves the removal of electrons from the target atoms. A magnetron can be used to produce H- ions. Van de Graaff generators have also been integrated with particle accelerators, shown in figure 3, for light ion beam generation. For heavier ion production, for example, an electron cyclotron resonance (ECR) source can be used. Figure 4 shows a schematic diagram of an ECR. At the National Superconducting Cyclotron Laboratory, neutral atoms have their electrons removed using an ECR ion source. ECR works by ionizing the vapor of a desired element such as chlorine and iodine. Further, utilizing this technique metals (Au, Ag, etc.) can also be ionized using a small oven to achieve a vapor phase. The vapor is maintained within a magnetic field long enough for the atoms to