Study Guides, Notes, & Quizzes

Ion Beam Diagnosis of Crystalline Materials

Description
ION BEAM DIAGNOSIS OF CRYSTALLINE MATERIALS By Debjit Kar (Y8760) Under guidance of Prof.V.N. Kulkarni Basic theory of Rutherford backscattering (RBS)     This is basically an event of elastic collision of mono-energetic particles from the target. There are basically four basic physical phenomenon involved in the collision: Energy transfer from a projectile to target nucleus in an elastic two body collision. This process leads to the concept of the Kinematic factor and the capability of
Published
of 11
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Related Documents
Share
Transcript
  ByDebjit Kar (Y8760) Under guidance of Prof. V.N. Kulkarni ION BEAM DIAGNOSIS OFCRYSTALLINE MATERIALS  Basic theory of Rutherfordbackscattering (RBS) This is basically an event of elastic collision of mono-energetic particles from the target.There are basically four basicphysical phenomenoninvolved in the collision:  Energytransferfromaprojectiletotargetnucleusinanelastictwobodycollision.Thisprocessleadstotheconceptofthe Kinematic factor  andthecapabilityofmassperception.  Likelihoodofoccurrenceofsuchatwo-bodycollision.Thisleadstotheconceptof  scattering cross section andthecapabilityofquantitativeanalysisof atomiccomposition.  Averageenergylossofanatommovingthroughadensemedium.Thisleadstotheconceptof  stoppingcross section tothecapabilityofdepthperception.  Statisticalfluctuationintheenergylossofanatommovingthroughadensemedium.Thisprocessleadstotheconceptof  energy straggling andtoalimitationintheultimatemassandthedepthresolutionofbackscatteringspectrometry.  Experimental set-up Itconsistsofmainlythreemainstages: 1) Productionofionsandacceleration,usingthe1.7MVTandetronaccelerator. 2) PreparationoftheRBSchamber. 3) Preparationoftheelectronicsforthedetector.  Tandetronaccelerator: This accelerator is made by High Voltage Engineering Europa(HVEV), which is a high current Tandem accelerator. The terminal voltage is in the range of 100 KV-1.7MV, generated by solid-state parallel fed Cockroft-Walton type voltagegenerator, with high voltage stability 30V and low terminal voltage ripple. The H-ions have been generated by the duoplasmatronion source model 358. The maximum currentavailable for H + and He + are 25 μ Aand 2 μ Arespectively. The RBS and channelingchamber have been set at 45 0 exit angle by the switching magnet.  RBS chamber: It consists of the following basic parts-a sample holder, a suppressor anda surface barrier Si detector.  Electronic set-up: The current from the detector has been initially amplified by the pre-amplifier. The subsequent main amplifier amplifying this signal creates a suitable pulseshape, thus optimizing resolution and count rate capability.  RBS of the sample Audeposited on Al using H +  Ions: H +  Charge state: 1  Energy: 2020 KeV  Scattering angle:165 0  Solid angle: .966msr  Beam current: 5 nA  Fluence: 2E+15 μ C  Energy/channel:4.14 KeV  Detectorresolution: 15 KeV  Thickness: 32 μ m(exp.) and 14 μ m(sim.)
Search
Tags
Related Search
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks