STAP Update Dec 2018 ESS Loki NBOA On

STAP Update Dec 2018 ESS - Loki

NBOA On order Design development greatly delayed: • Planned completion Sep 2018 • Now expected February 2019 Reason: • Delays in the NBPI design and finalization • ESS changing the requirements of the alignment devices

Guide • • Tender documents completed CTV review with ESS passed STFC commercial stakeholders currently reviewing Tender to go live in Dec 2018 and close in Feb 2019 • Guide tender includes guide and vacuum flight tubes • Some questions have arisen regarding air activation, but we believe we can see a solution for Lo. KI, so this is not a show stopper

Choppers • New design engineer recruited • Loki chopper design has now started

Heavy Shutter

Heavy Shutter Neutronics initial assessment completed • Highlighted importance of stopping neutrons from scattering back into the guide from the sides, above and below • Current Shutter thickness has been proven to be sufficiently thick • Weight optimizations look possible, however the mechanical design will be engineered with a high level of prudence such that material changes can be made (more weight added) if necessary 20μSv/hr

Frame Overlap Mirror Planning to have a frame overlap mirror in the heavy shutter guide piece with a nominal 32 Å cutoff (m=1, 3. 117 deg, 459 mm) • • Issues? Experience of the STAP?

Collimation Selector • Collimation Selector in Detailed Design • To be filled with neutron blocking material – not yet defined • Initial neutronics work shows that we may be able to reduce shielding.

Collimation Selector Material considerations: • Steel: • High mass results in engineering complications • Cross section gaps (between 20 kev-1 Me. V) • HDPE & Borated Poly: • Out gassing of short chain hydrocarbons and processing agents could coat the guide • Out gassing hindering vacuum quality • High Performance Plastics PEEK or Noryl: • Low hydrogen content resulting in low neutronic performance • B 4 C composites: • Will not stop neutrons above 1 Me. V • Some outgassing potential

Collimation Selector Material considerations: • Steel: • High mass results in engineering complications • Cross section gaps (between 20 kev-1 Me. V) • HDPE & Borated Poly: • Out gassing of short chain hydrocarbons and processing agents could coat the guide • Out gassing hindering vacuum quality + Vac&Bake? • High Performance Plastics PEEK or Noryl: • Low hydrogen content resulting in low neutronic performance • B 4 C composites: • Will not stop neutrons above 1 Me. V • Some outgassing potential

Sample Area • New roof access concept developed • Better ergonomics for cryo sticks etc. • Snout design developed: • Prototypes to be tested in Jan 2019

Sample Area Multiple fixedlength tubes Extendable position (200 mm travel) 2000 mm L 3 L 2 1300 mm level “ 0” - platform 790 mm Z- & X-translation table (under the platform? ) Space for water baths/ancillary equipment Top view

Sample Area • Sample Stack Current Concept • • Z – 350 mm X – 200 mm Y – Bolt on large translation stages for dedicated SE only Rotation – Bolt on for dedicated SE only • Y may be needed to centre samples • Pool SE will have capability for off-line alignment to standardized centre • User SE may not have capability for off-line alignment • ± 0. 1 mm precision required for SANS sample centring of small samples • GISANS requires higher precision, so would need own stack

Sample Area • Rotation … • STAP advice previously was to have this permanently installed • Current plan has option for different rotation stages depending on mass of SEE and precision needed. • Thoughts? • Beam height • 1. 3 m – agreed with SKADI • Could be lower – investigating workspace standards

Detectors • • Design of pre-amp box developed - prototype on order Module configuration developed - prototype on order Frame design underway Beamstop design underway

Detectors • Test detector tubes delivered

Detectors Layout optimizations on-going • Currently gaps in the coverage are being accepted as a compromise to allow the efficiency variation with angle to be reduced • Coverage is now < 45° • Discussions with DMSC are underway on how to handle the array in Mantid • Once we have a test module, we will work with DMSC to test it with their full hardware/software stack 45°

Detectors

Detectors