1.) How
do I arrange to do an
experiment at SNS? |
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1) Here are some instructions for arranging beam time at SNS:
- Submit a proposal. Go to the User Info page and use the link under Resources to get to the ORNL Neutron Science User Program web site. Read the information, especially the Policies and Guidelines. Follow the instructions on how to become an SNS user, as well as important information concerning site access, training, experiment and sample handling. The User Info page also has a link with Instructions for Accessing the Integrated Proposal Tracking System. Use this link, and follow the instructions to submit a proposal.
- Register. Once your proposal has been accepted, contact the Users Office as soon as possible. Please note that for citizens of certain countries it can take up to eight weeks to arrange site access. This may affect the scheduling of your beam time, so contact the user office as soon as possible.
- Arrange dates. You will be contacted by the Magnetism Reflectometer Instrument Scientist to arrange specific dates for your beam time.
- Arrange Travel and accommodations. Make your travel arrangements and reserve your hotel accommodations. Information on Oak Ridge hotels is available on the Visitor Info page.
- Confirm. Finally, contact the Users Office to confirm dates and arrangements for your visit.
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2) What
size samples can I bring? |
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2) Maximum
sample size is limited
by sample environment
requirements:
- Samples run at
room temperature
with no magnetic
field have virtually
no restrictions.
- Samples run at
room temperature
that are placed within
the electromagnet
pole pieces have
a maximum height
of 100 millimeters.
- Samples run at
low temperature require
mounting inside our
closed cycle helium
refrigerator, and
have a maximum size
of 20 x 20 millimeters.
Minimum sample size
is approximately 10
X 10 millimeters. Sample
sizes smaller that
this will generally
require more beam time
than is reasonable
for a fully subscribed
instrument.
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3) What
sample thickness can
I study? |
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3) Film
thickness oscillations
can usually be resolved
for thicknesses ranging
from a few monolayers
up to approximately 7000 Å.
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4) What
do I do if I want my
samples returned to me? |
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4) If
you are present at the
SNS when your samples
are run and they have
been cleared by the Radiological
Control Group, you can
carry them back with
you. If you are
not present, or you leave
before one of your samples
is completed, we can
ship samples back to
you once they have been
cleared by the Radiological
Controls Group, provided
we have a complete shipping
address, with phone number,
a complete MSDS for the
sample and a Fed Ex (or
other shipping service)
account number to which
the shipment will be
billed.
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5) What
range of temperatures
and magnetic fields can
I run at? |
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5) The
beam line 4A closed cycle
helium refrigerator has
a temperature range between
4.2 and 450 Kelvin. To
accommodate the refrigerator
(which accommodates 20
X 20 millimeter samples),
the magnet pole pieces
are placed 50 millimeters
apart, which limits the
maximum magnetic field
to approximately 1.2
Tesla. For samples
approaching the minimum
sample size (10 X 10
millimeters) running
at room temperature and
mounted outside the refrigerator
the pole piece gap can
be reduced, which increases
the maximum field to
approximately 3 Tesla.
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6) Hey,
where did the beam go? |
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6) While the SNS facility operates seven days a week, twenty four hours a day during normal operations, there are scheduled periods during operations cycles when the SNS does not produce neutrons for users (maintenance periods and accelerator physics schedules). No data will be collected during these periods. This is normal. Check the long term run schedule to view the listing of these periods.
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