SPACESHIP EARTH: BUILDING NAIN NEUTRON MONITOR
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| The Nain neutron monitor shares
a site owned by the Canadian Broadcasting Corporation (CBC).
Here, the three vans that house the monitor can be seen
left of the CBC building. They were loaded with lead
and other components of the monitor and then shipped to Nain by barge.
In front of the vans are unloaded pallets of lead rings
to be used in monitor
construction.
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PROLOGUE.
The idea of a cosmic ray monitoring station
in Nain was hatched by University of Delaware scientists in 1994,
when computer simulations showed that a station in northern
Labrador would fill a major gap in the existing network
of neutron monitors. Nain, the northernmost Town in Labrador, is
near the optimal location. After obtaining research funds
from the US National Science Foundation, a team from the
University of Delaware visited Nain in May 1998 and confirmed
that the Town has the technical resources and infrastructure
needed to support a modern cosmic ray monitoring station.
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| The monitor vans with contents
weigh more than 12 tons each,
so frost heave and settling in the soft Nain soil
was a concern. Our contractor excavated a 10 foot
deep trench and filled it with 30 truckloads
of blast rock --- a sound foundation for the project.
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PHASE 1 CONSTRUCTION.
The heavy lifting was done in Phase 1.
Materials required for the station were shipped
to Nain via barge during the Summer of 1999.
In September 1999 rock fill and footings were installed,
and the monitor vans were placed on site. The
lead and polyethylene enclosure for the detector
tubes (6 in each van) were assembled on platforms
in each van. The vans were then shut to await
Phase 2 Construction.
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| Timber
footings 12 feet long
and 4 feet wide were placed on the rock fill to support the ends of
each van. A backhoe was used to lift the vans into place. |
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A neutron monitor is very sensitive
to its surroundings. In Nain, we were concerned about drifting
snow outside the van. To mitigate this sensitivity, we built a
steel platform to hold the monitor a few feet above ground level. |
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The outer shell of the monitor
consists of white polyethylene sheets. This shell was partially constructed,
and then the lead rings --- or "rings with wings" as they are
poetically called --- were lifted in place with the help of a motorized
hoist. |
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A column of 18 lead rings, each
weighing 200 pounds, was assembled for each detector tube.
The outer polyethylene shell was then finished, and an inner
circular sleeve of polythethylene was slid into each column
of lead. The monitor assembly is now ready to receive the detector
tubes. |
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| The completed assemblies in each van
are ready to receive the detector tubes and data
collection units. This view is from the North, as
seen from a nearby road.
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Two views from the rear
of the site: (Left) From the southwest.
(Right) From the southeast. |
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For more information about neutron monitors and
the uses of cosmic ray data, please visit our
Neutron Monitor Home Page.
CREDITS
- Spaceship Earth Concept: John W Bieber and Paul Evenson
- Funding: US National Science Foundation
- Engineering, Photography: Leonard Shulman and James Roth
- Contractors: D & J Construction Ltd, Bonnie Bay Contractors
Ltd, Sea Box Inc, Commercial Transport International,
All-Fab Building Components Inc, and
Southern-B Construction
- Assistance and Advice: Nain Town Council, Nain Town Manager,
CBC St Johns
THANKS TO ALL !
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