Interfaces with the SNS Project for the ARCS Instrument

1
Interfaces with the SNS Project for the ARCS
Instrument
ARCS Construction Project Review DOE
Germantown Aug. 9, 2004

• Doug Abernathy
• ARCS Hardware Project Manager

SNS Instrument Systems
Oak Ridge
2
ARCS internal interfaces

• The ARCS project is spread across three
  institutions communication is key to keeping
  things on track
• The instrument scientist (D. Abernathy) has
  visitor status at Caltech as well as being on the
  SNS staff
• Access to financial information to ease gathering
  of costs
• Weekly meetings using SNS videoconference
  equipment
• B. Fultz also has participated
• SEQUOIA team also attends to discuss common work
  and coordination of design of the adjacent
  beamlines
• ARCS has an assigned person in Caltech purchasing
  to watch over procurements
• Some improvement needed in communicating status
  of contracts more attention to including
  documents in SNS system since information is not
  kept just down the hall
• Communication to IDT via web site, meetings
• Recently more directed at software efforts

3
Institutional interfaces between ARCS and SNS

• A Memorandum-of-Agreement and Project Execution
  Plan were signed early in the project
• Not often referred to, but shows a level of
  commitment
• Collection of spending information has been
  consolidated at SNS
• Recent rebaselining will put ARCS under standard
  project controls activities at the SNS
• Facilitate reporting to Caltech, DOE
• Ultimately decisions for the project are make in
  the procurement process
• B. Fultz has to approve based on Caltech
  procurement policies
• Large purchases are evaluated by a committee that
  includes SNS personnel
• Everyone understands that the best instrument
  will be one that is robust and can be maintained
  by the SNS after turnover of ARCS at the end of
  the project

4
Prototyping effort benefits

• Detector in vacuum tests were a joint ARCS/SNS
  venture to prove the concept
• Requirement by the Backscattering Spectrometer
  for running He-3 LPSDs in vacuum
• Identification and testing of ZHIP mix should
  benefit several instrument that need low albedo
  instrument shielding with good vacuum
  characteristics
• Neutronic calculations enabled both ARCS and
  SEQUOIA to move forward with the intimate layout
  proposed
• ARCS gained from the SNS experience with a
  prototype Fermi chopper
• ARCS will use shared developments from other SNS
  groups

5
Personnel Protection System

• ARCS is the first instrument scheduled to operate
  with no curved guide and/or secondary shutter
• Intent is to serve as a model for this type of
  instrument
• P. Wright has already met and discussed planned
  modes of operation for ARCS
• Clarification is needed on some points
• Can a trapped key system be used to provide for
  personnel safety beyond radiation expose, e.g.
  vacuum vessel access?
• Does the shielding around the sample area need to
  be designed for the worst case imaginable, or
  will an area radiation monitor be sufficient to
  catch an unexpected case and shut the beam?

6
Neutrino detector nSNS

• A proposal to place a neutrino detector in the
  corner next to ARCS has been made
• Strong statement from SNS that no interference
  with instruments is allowed

• Meetings among nSNS, SEQUOIA and ARCS have
  started to address
• Keep-clear area for accessing ARCS
• Floor loading issues, which determine the size of
  the neutrino detector
• Access for all parties to crane items into the
  pit area

7
Installation

• Met with SNS installation team (R. Connatser, T.
  Fornek) in July to kick off inclusion of ARCS in
  the overall planning for installation.
• Installation plan will be reviewed in November
  SNS review
• ARCS should have a reasonable access to shared
  resources such as the crane by being first on the
  North side of the target building
• First cut at assigning resources to ARCS tasks
  has been made
• ARCS will have to provide descriptions of
  installation activities (work packages) for
  inclusion in a global work plan and evaluation by
  SNS estimators
• Additional information
• 1M is still an overall estimate for
  installation costs of an instrument. No specific
  analysis of ARCS schedule was made.

8
CD-4 for the SNS

• The current plan is to do the neutronic
  measurements necessary to satisfy CD-4 for the
  overall SNS project on ARCS
• An instrument on the water moderator is
  preferable to avoid issues with cryrogenic
  problems.
• E. Iverson has drafted a plan to use a small
  detector setup at the ARCS sample position to
  determine the performance of the target and
  moderator system as required for CD-4.
• E. Iverson will evaluate a backup plan in case of
  a delay in installing some part of ARCS by the
  time of the CD-4 measurement
• Use chopper positions with temporary shielding as
  necessary to open the beam