MINERvA Module Mapper

1
MINERvA Module Mapper

• Robert Bradford
• University of Rochester
• March 1, 2006

2
Overview

• Detector and modules
• Purpose of mapping
• Overview of proposed mapper
• Radiation Safety
• Mechanical Safety
• Conclusions

3
MINERvA Detector
Detector is large stack of units referred to as
modules
Module is steel frame with sheet of scintillator
with embedded readout fibers.
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Mapping

• Mapping involves scanning the scintillator in
  the modules with a radioactive source.
• Quality control measure
• Allows us to track detector performance as
  function of position
• Helps us understand local properties of
  scintillator

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MINOS Mapper
Scanning head 5 mCurie source
Gantry holding source rides on rails below
scanning surface
scintillator module
Mapper ran at ANL never brought onto FNAL site.
6
Initial Concept Sketches
Dual scanning heads
Mapper
Module
Strongback on floor.

• Mapper mounts to strongback moved into position
  by crane
• 2 scanning heads should further decrease
  scanning time but calls for 2 sources.
• Rochester engineer continuing to work on design.

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Radiation Safety
8
Sources/safety

• Proposing to use 2 Cs-137 sources of 5-10 mCurie
• Sources to be rigidly attached to mapper
• Will be housed in lead cone

Spot will be exposed only while mapper in
operation.

• Operators will be source and source monitor
  trained.

9
Mapper location

• Mapper will remain in fenced area entire time.
• Strongback/module will be moved to mapper
  location
• Additional burden on crane minimal
• Area will be posted with radiation area signage
  at all access points.
• Area will remain pad-locked with strict key
  distribution
• Computer controlling mapper will remain in fenced
  enclosure

10
Lifting Mapper

• Crane lifting of mapper has been minimized
• Will follow precautions for handling overhead
  loads
• Source will be locked in to garage position
• Completely shielded while mapper moving
• should eliminate hazards underneath mapper
• Rigidly held into position with pin/locking
  mechanism

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Wideband Hall Layout
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Mechanical Safety
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Mechanical Systems
x-motions One for each source 12 ft

• Scanning heads incorporate 3 linear motions
• Motor turns lead screws driving carriages
• Carriages mount to rails incorporating bearings

y-motion moves entire head 14 ft
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Safety Measures

• Mapper will be fenced in already as discussed in
  previous section.
• Eliminates hazards for most in Wideband Hall
• Operator may be within enclosure while mapper is
  running.
• Will have to verify setup
• Physically un-park sources
• Start the computer controls
• May want to monitor data acquisition

15
Mechanical Safety
Isolate mapper from operators station (fence
with interlock on door)
Operator Controls
Mappers Cage
Fence
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Timeline

• Winter/spring 2006 Design work
• Summer 2006 Construction and assembly
• Fall 2006 Optimization studies
• Late 2006 Mapper tested on prototype module
• Early 2007 Further optimization based on
  prototype test
• Late 2008 Detector assembly and mapping

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Summary/Questions

• Currently planned safeguards should permit
  operation of the mapper in accordance with lab
  safety guidelines.
• Other questions
• Can we run the mapper un-attended at night?
• Do the measures look do-able from facilities
  standpoint? Are they okay with WBS8?
• Do we need to think about ergonomics?
• Set up requires connecting 40 cables to module,
  which will be on the floor