1. Interfaces with the SNS Project for the ARCS Instrument Doug Abernathy ARCS Hardware Project Manager ARCS Construction Project Review DOE Germantown Aug. 9, 2004 SNS Instrument SystemsOak Ridge

2. SNS Instrument SystemsOak Ridge 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. SNS Instrument SystemsOak Ridge 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. SNS Instrument SystemsOak Ridge 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. SNS Instrument SystemsOak Ridge 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. SNS Instrument SystemsOak Ridge Neutrino detector SNS 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 SNS, 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. SNS Instrument SystemsOak Ridge 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. SNS Instrument SystemsOak Ridge 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