Tertiary Collimators

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Tertiary Collimators Residual Dose Attenuation
In Air MARS Graphic User Interface
DPA At High Energy
September 20, 2006 Accelerator Division
Seminar Fermilab
Maura E. Monville
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• Project 1. Tertiary Collimators
• Project 2. Residual Dose Attenuation In Air
  
• Project 3. MARS Graphic User Interface
• Project 4. DPA At High Energy

Outline
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Tertiary Collimators OptimizationIP1 and IP5

• Damage Sources
• Collimator Tails
• FNAL Calculations From CERN Source-Storm Files
• Beam Gass
• FNAL Model Spans 512 m From IP5/IP1
• Purpose Of Tertiary Collimators
• Remove Particles Scattered By Interaction With
  Residual Gas And Collimator Tails
• Protect Expensive Collimator Components From
  Damage In Case Of Beam Failure

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Tertiary Collimators Optimization
TCTH and TCTV
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Isocontours For Residual Dose Attenuation In
Air
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Isocontours For Residual Dose Attenuation In
Air
Dose At Distance r From Cylinder Surface
Attenuation Function
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Extension Of MARS Graphic User Interface

• GUI Extension Strategy Plan
• Prevent erroneous command sequences
• Detect Correct Entry Typos
• Improve
• Self Diagnostic
• Data Analysis Postprocessing
• Consistency Robustness
• Environments Integration Exclusion
• Histograms, Tracks, Geometry
• Look Feel
• Add New Features
• Integration Of New Features With The
  Pre-Existing Framework

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Extension Of MARS Graphic User Interface

• Problems Fixed
• Tracks
• Independence Of The Geometry Environment
• Start-track / End-track Negative Number Entry
• Integration With The Navigation Function
• GUI Response To Typos
• Interaction With The Magnification Function
• Interference With The Histogram Environment
• Integration With The Geometry Environment
• Histograms
• OFF/ON Toggle Histogram Resetting
  
• OFF/ON Toggle Integration With The Histograms
  Selection List
• Raised Point Info Widget Numerical Upper Limit
  ( )
• Fixed Logarithm Data Representation
• Fixed System Response To Meaningless Field
  Entries

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Extension Of MARS Graphic User Interface

• Problems Fixed
• Histograms
• Graphic Objects / Texts Overlapping Caused By
  View Rotations
• Integration With The Geometry Environment (Fill,
  WireFrame)
• Interference With The Tracks Environment
• Integration With The Navigation Function

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Extension Of MARS Graphic User Interface

• New Features
• Created Four GUI Window Sizes
• Small, Medium, Large, Extra-Large
• Added Button For Histogram Data Arbitrary
  Normalization
• Improved Histogram Data Display Resolution
• (16,16) (16,8) (16,4) (16,2)
• Created Reset Button
• Brings Back To The Starting Conditions Erasing
  The Work Session
• ON/OFF Toggle Implemented For Both Tracks And
  Histograms

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Extension Of MARS Graphic User Interface

• New Features
• Added Button For View Format Change
• 11, 169
• Integrated User Add-On Texts Arrows With
• Navigation System
• View Format Change
• Arbitrarily Rotated Colored Text Strings
• Linked Tested Tcl/Tk Extension Library With
  MARS GUI
• Added Heavy Ions MARS Identifier To Track Point
  Info
• Limited Geometry (Fill / Wireframe) Integrated
  With The Added Features

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Extension Of MARS DPA Model

• Already Implemented Tested In MARS
• DPA From Nuclear Interactions
• To Be Developed Integrated
• DPA From Electro Magnetic Interactions

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Extension Of MARS DPA Model

• Nomenclature
• Displacement
  
  Lattice Atom Knocked From Its Lattice Site
• Displacement Per Atom (dpa)
  Average Number Of
  displacements per lattice atom
• Primary Knock On (pka)
• Lattice Atom Displaced By Incident Particle
• Secondary Knock On (ska)
• Lattice Atom Displaced By pka
• Displacement Rate (Rd)
• Displacements Per Unit Volume Per Unit Time
• Displacement Energy (Ed)
• Energy Needed To Displace A Lattice Atom

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Extension Of MARS DPA Model

• Model Formulation
• Determine Number Of Displaced Atoms Produced By A
  pka

• To First Order An Incident Particle With Energy
  E Can
• Displace Lattice Atoms
• (Either Itself Or
  Through Knock-ons)
• For There Are No
  Displacements
• For There Is One
  Displacement
• For Assume Energy
  Shared Equally In
• Each
  Collision
• Average Energy
  Transfer Half Of
• Incident
  Energy

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Schematic

• Process Stops When Energy /Atom Drops Below 2Ed
• ? No More Net Displacements Can Be Produced

tka
ska
pka
or
Number Of Displaced Atoms Produced By a pka
E
Energy / atom
Kinchin-Pease model
displacements
1
2
4
?
T