1. Status of Procurements 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 Prototyping Efforts Based on risks identified early in the project (March 2002 Baseline Review) several efforts were launched: Neutronics calculations Prototyping detectors in vacuum Testing outgassing of neutron absorbers in vacuum Single crystal closed-cycle refrigerator Detector mounting scheme Total cost of the efforts (approximately): Hardware $250,000 (vacuum system, detectors, mounting system, CCR and goniometer, etc.) Labor $250,000 About 4% of total project cost Many components will serve a purpose in the future

3. SNS Instrument SystemsOak Ridge Trade off Between Dose and Size for ARCS Beamstop 1235

4. SNS Instrument SystemsOak Ridge Beam Stop Comparison Early study used to determine reasonable sample position for SEQUOIA. Quantifies size vs. cost for Value Engineering purposes Case 4 and 5 are for more tungsten CostWeight (kg)Diameter (m) Case 1$174,464105,5903.2 Case 2$174,464105,5903.2 Case 3$209,745103,5523.2 Case 4$775,89874,7422.4 Case 5$1,094,15361,5292.2 Based on Dose Rate Analysis of C. Slater and Engineering analysis of R. Williams Updated calculations ongoing, but significant differences are seen due to a re-evaluation of the spectrum from the moderator (E. Iverson)

5. SNS Instrument SystemsOak Ridge New material for internal shielding – ZHIP mix After an extensive search lead by Ralph Niemann, we have found a producer of the B 4 C + CF 2 material: Dielectric Sciences, Inc. Chelmsford, Massachusetts Contacts: Jerry Goldlust, Steve Rigby They have dubbed this “Zero Hydrogen In Product mix” ARCS has contracted with them to supply samples and design studies for our needs. They are affiliated with an ISIS supplier for crispy mix and will bid on supplying material to the MERLIN instrument.

6. SNS Instrument SystemsOak Ridge ZHIP mix properties vs. crispy mix Binder typically 6% by weight (DSI says best workability) Good mechanical properties, low shedding of grit Easily put on Al backing Procedures worked out to get high density (1.9 gm/cm 3 ) Outgassing performance excellent compared to epoxy based mixture Neutronic performance comparable to standard crispy mix

7. SNS Instrument SystemsOak Ridge Outgassing measurements Used ARCS large test vessel Procedure (Rate-of-rise test) Load sample Pump; T=0 when P<1mTorr At desired time, note pressure and close gate valve Wait dt ~ 15s Note pressure Open gate valve Calculate dP/dt and q A

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11. SNS Instrument SystemsOak Ridge ARCS Procurement Status Overview ItemDesignProcurementCost Core Vessel InsertDoneAt SNS$92,400 Shutter InsertDoneIn manufacturing$59,610 Guide – shutterDoneExpected 11/04$60,000 Guide – beamlineDraft spec~1 year delivery$260,000 Guide – endConceptual$30,000 T0 chopperDraft spec~ 9 month delivery$261,000 Fermi chopperDoneExpected 2/05$410,000 Slit Package AssemblyUnder testing~12/05$40,000 LPSDsDoneExpected 10/04$1,100,000 Electronics & MountingFinal testingAs needed$600,000 Vacuum chamber – sample isolation, vessels & pumps Draft spec; Pre-bid meeting 6/04 Contract ~10/04 ~1 year delivery $1,200,000 Shielding – Poured-in-placeDoneSNS organized$30,000 Shielding - OtherNeutronic evaluation ongoing $1,000,000 Green: Committed $ Blue: Expected by 10/04

12. SNS Instrument SystemsOak Ridge Early Procurements Driven by Target Schedule Core vessel and shutter insert components procured through common SNS effort – deliveries and testing on schedule Need for shutter guide and housing by Nov. 2004 prompted a division of the guide procurement into different sections – Shutter guide specified and procurement awarded to CILAS; design review complete; production started – Beamline guide specification drafted; expect award in Sept. 2004 with delivery ~1 year later – Guide end between Fermi chopper and sample is dependent on details of sample area design, performance gains depend on sample size and tolerance for divergence Shutter guide is an example of value engineering – m=2.5 chosen compared to nominal m=3.6 original design

13. SNS Instrument SystemsOak Ridge Guide gain varying shutter guide coating

14. SNS Instrument SystemsOak Ridge Percentage loss varying shutter guide coating

15. SNS Instrument SystemsOak Ridge Fermi Chopper SKF/Revolve chosen as supplier – other possible vendors are based in Europe and posed risks to efficient coordinated design Building on SNS prototyping experience, the slit package assembly will be designed and built by ARCS in collaboration with the SNS Chopper Group while the magnetic bearing specialists provide proven bearing and phase control plus housing and service connection Contract includes integrated testing of 3 chopper systems plus one additional rotor using the translation table that will allow for quick changes of resolution in operations Current slit package assembly activities – Evaluation of possible absorbing slat materials complete – 10 B coated, 0.35mm thick material most absorbing but a less expensive boron-fiber composite may be adequate for lower energies – Final FEA analysis underway – Assembly jig and test pieces being constructed at ANL (R. Niemann) – Spin test contract in place to validate design for final production Delivery of systems foreseen for early 2005 (not a time critical activity)

16. SNS Instrument SystemsOak Ridge Considerations for the ARCS first chopper area Purpose: Reduce background at detectors by blocking beam when protons hit the target – Eliminate unwanted neutrons both before and after desired incident energy Two types currently used as spallation sources – Horizontal axis (ISIS & Lujan): 30 cm Inconel – Vertical axis (IPNS): ~inches Be Engineering study done to see feasibility of producing fast (>=120 Hz) choppers of both designs – Magnetic bearings for speed and reliability – Use FEA to guide design

17. SNS Instrument SystemsOak Ridge Vertical Axis T0 chopper scientific design Typical parameters – Channel width min. 8 cm – Channel width max. 10 cm – Radius 25 cm – Rotor weight ~800 lbs. Operation at 30 Hz intervals – Max. to be determined by detailed engineering ~120 Hz Open questions – How much material really is needed in the beam at T0? – Can crystal alignment be done with chopper operating?

18. SNS Instrument SystemsOak Ridge Geometric beam blockage for T0 choppers - Time Operating at 120 Hz with minimum of 30cm of Inconel in beam at T0 and phased for 1000 meV (vert. axis)

19. SNS Instrument SystemsOak Ridge Geometric beam blockage for T0 choppers - Energy Horizontal axis: wide bandpass with high energy leakage Vertical axis: beam blocked outside of incident energy

20. SNS Instrument SystemsOak Ridge Detectors Reuter-Stokes chosen from 2 bidders to supply LPSDs – low risk based on existing instruments world-wide Cost is reduced by using SNS (DOE) supplied He-3 roughly 20%. This represents a contribution by SNS to the IDT budget. First 8 detectors received at SNS at the end of July. Once performance is confirmed remaining tubes will be manufactured by end of October. Placement of this order (probably 2 nd largest single contract) represents a large reduction in risk to the project. Electronics and basic hardware for 8-pack detector modules are proven – a final iteration on the design will be built to test for problems before production Evaluation of the frame to hold detectors within the vacuum vessel is ongoing using a mock-up at ANL There will be a smaller order (~16 tubes) for special detectors around the beam exit – design to be completed

21. SNS Instrument SystemsOak Ridge Design goals for the ARCS vacuum vessel Use SNS standard mounting flange for sample environment equipment; accommodate sample motion esp. rotation Provide cryogenic vacuum for sample with quick (< 1 hr) changeout and good access for special equipment Minimize/eliminate neutron windows (thin Al), particularly near sample Mount and provide access to neutron detectors ( turnaround ~ several hours) Accept additional components – variable aperture, oscillating radial collimator Include internal neutron shielding (“crispy mix”) Allow for external neutron shielding to block background Non-magnetic material ~2m around sample Simple, turnkey operation of overall system

22. SNS Instrument SystemsOak Ridge ARCS vacuum vessel procurement status Strategy: Look for a single vendor to produce a turnkey system, unless there is added value for separating sample and detector areas. Sample isolation area and detector area specifications to be sent together to interested parties. A vendor pre-bid meeting was held at SNS June 29, 2004. – Distributed preliminary specifications – General goals as well as some engineering constraints were presented – Tour of the target building and ARCS beamline area Total of ~10 vendors attended or requested to receive the final request-for-proposals Discussion with one manufacturer indicates the gate valve concept is feasible, could be integrated into a sample vessel and tested separately Sample isolation is an important value engineering concept – cost recover for one hour of SNS beamtime would be >$30,000

23. SNS Instrument SystemsOak Ridge Shielding Much of the shielding work has been waiting for more feedback from neutronic calculations for both dose rate (0.25mrem/hr) and background Initial SNS shielding studies performed by an external ORNL computational group – Not necessary in tune with common practices in neutron scattering instrument – Little added institutional learning – Source file used was common to all instruments and overestimated high energies Decision taken for this effort to move to an SNS computational group – Group is shared with target – some delays while important issues were addressed – Recently many beamlines are getting a second look with a more realistic source – particularly advantageous for ARCS in near backscattering from target

24. SNS Instrument SystemsOak Ridge Personnel issues Additional effort will need to be “procured” for ARCS to meet its schedule goals Argonne effort will end with FY04 – Core instrument team at ORNL (scientist & engineer) now – Ramp up of intensive designer work makes long distance coordination more difficult – More detailed interaction with SNS shared activities and target related installations – Ralph Niemann will retire A statement-of-work for a designer is drafted Discussions for engineer time to replace R. Niemann’s efforts coordinating chopper activities for ARCS underway