SUPL The Stawell Underground Physics Laboratory Andrew Stuchbery
SUPL - The Stawell Underground Physics Laboratory Andrew Stuchbery, Department of Nuclear Physics, ANU, for the SABRE Collaboration 1
Motivation: Dark Matter WIMPs in the Galactic Halo Annual modulation expected 2
Motivation: DAMA/LIBRA Na. I PMT Na. I Based in Gran Sasso lab (Italy) 250 kg of Na. I scintillator crystals 3
Motivation: DAMA/LIBRA • 9 sigma signal over many years • Correct phase • But not independently confirmed 4
Motivation: DAMA/LIBRA • But not independently confirmed 5
Dark Matter Signal? • DAMA/LIBRA finds a robust modulation signal that may be due to dark matter. • First dark matter detection or a seasonal variation? • Requires testing: Ø Complementary measurements in Southern Hemisphere Ø Ultrapure detectors (Na. I crystals) Ø Similar conditions in Italy (Gran Sasso) & Australia
SABRE 7
Both Hemispheres
SUPL – what and where text 9
Stawell Region Wine Industry Grampians National Park 10
Stawell Gold Mines owned by Canada-based Newmarket Gold. Delivered 8504 ounces, average grade 1. 48 grams per tonne, 2 nd quarter of 2016. Decline mine, 1. 6 km deep. Caverns with electricity, optical fibre, reachable by car/truck. 11
SUPL cf. other labs Stawell Gold Mine Jin Pin g 12
Background measurements • Safety pod becomes a counting lab • Background levels similar to Gran Sasso 13
Australian Collaboration Elisabetta Barberio (University of Melbourne) “Prof. Elisabetta Barberio (Melbourne) is the national contact physicist for the Australian institutions. Prof. Andrew Stuchbery (ANU) is the deputy. Prof. Geoffrey Taylor (Melbourne) will be the project manager. ” Australian Research Council Grants for the SABRE experiment LE 16 Detector system for the First Australian Experiment on Dark Matter Barberio, Mould, Stuchbery, Taylor, Thomas, Williams et al. Funded LE 17 Full Scale Detector System for the First Australian Dark Matter Experiment Barberio, Stuchbery, Mould, Williams, Taylor, Urquijo, Lane, Duffy, Simenel, Wallner, Duffy, Thomas, Hill, Jackson, Calaprice, Vignoli. Requested LE 17 Digital data acquisition for dark matter detection and nuclear science Stuchbery, Urquijo, Lane, Barberio, Kubota, Kibedi, Simenel, Williams. Requested DP 17 Stawell Underground Physics Laboratory: Dark Matter Detector Development, Lane, Stuchbery, Barberio, Calaprice. Requested 14
Australian Collaboration University of Melbourne (Particle Physics) Elisabetta Barberio, John Koo, Chunha Li, Katherine Mack, Philip Urquijo, Geoffrey Taylor, Francesco Nuti Tasks: (1) Shielding– with ANU (2) Simulations (3) Purification and drainage. (4) Milestone/project management. Australian National University (Nuclear Physics) Gregory Lane, Cedric Simenel, Andrew Stuchbery, Anton Wallner Tasks: (1) Vessel design and construction (with advice and support from Roma and LNGS) (2) Na. I(Tl) crystals– AMS for lead and Iodine and quenching factor measurements - with Melbourne. (3) DAQ, trigger and pulse shape analysis – with Melbourne (4) Liquid Scintillator. University of Adelaide (Theoretical+Experimental Particle-Astroparticle Physics) Bruce Dawson, Gary Hill, Paul Jackson, Gavin Rowell, Anthony Thomas, Martin White, Anthony Williams. Tasks: (1) Slow control and (2) Data storage & computing systems – lead by Adelaide with the assistance from Melbourne and Swinburne. Also assisting ANSTO with background measurements and monitoring. Swinburne University of Technology (Astro & Astroparticle Physics) Alan Duffy, Jeremy Mould Tasks: (1) Outreach in cooperation with ARC Centre of Excellence for Particle Physics at the Terascale (Co. EPP), (2) Assisting Adelaide with slow control and data management. Australian Nuclear Science and Technology Organisation (ANSTO) (Nuclear Physics) Dale Prokopovich Tasks: Background measurement and monitoring in SUPL – lead by ANSTO with assistance from Adelaide, Melbourne, and ANU. 15
Planning Process USER REQUIREMENTS ENGINEERING REPORTS & DESIGN 16
The Final Lab Design 17
Laboratory Operations • The Australian Nuclear Science and Technology Organisation (ANSTO) will operate a low background facility with 6 to 8 Germanium counters. • The operators of the Stawell gold mine (Newmarket Gold Inc. ) will provide electricity, internet through optical fibre, ventilation, training and security for a total in-kind value of about $100, 000 per month. • Northern Grampians Shire will own SUPL. ANSTO and the University of Melbourne will jointly operate SUPL. 18
Laboratory Characteristics • Clean lab similar to SNOLab • • Radon specific activity: < 100 Bq/m 3 in the “clean area” Temperature: 19± 2˚C Relative humidity 40% - 50% Monitoring and remote control of lab climate and air flow • Use of low radiation concrete and finishing; we are sampling the sand cement • Surface coating to inhibit Rn 19
SUPL Detail 20
Timeline 21
What makes SABRE unique? Spokesperson: Frank Calaprice (Princeton) 22
SABRE Crystal Purity Slide from Francis Froborg 23
Na. I Purity: AMS @ ANU 14 UD tandem • Versatile instrument • Radionuclide isotope ratios through atom counting • High particle energies • Sensitivity 10 -12 – 10 -16 • No isobaric background (molecules destroyed by stripping in tandem) • Isotopic background clearly identified 24
Na. I Purity: AMS @ ANU 55 Fe 2. 7 years 3 H 12. 3 44 Ti 60 63 Ni 100 32 Si 140 39 Ar 269 14 C 5 730 59 Ni 75 000 41 Ca 104 000 81 Kr 230 000 79 Se 280 000 36 Cl 301 000 26 Al 720 000 10 Be 1 388 000 60 Fe 2 600 000 53 Mn 3 600 000 182 Hf 8 900 000 129 I 17 000 236 U 23 000 239 -244 Pu, 247 Cm - 81 000 25
Na. I Purity: AMS @ ANU • 129 I • 210 Pb • straightforward; sensitivity better than 129 I/I=10 -14 a challenge: o Pb does not easily form negative ions; tested various chemical forms (fluorides, oxides etc. ) to find the best way to produce Pb beams o how to best dissolve Na. I, separate 210 Pb and spike with stable Pb? o what is our background limit for 210 Pb detection? 210 Pb Status: o Lead-fluoride did not work well (low beam current) o Lead-oxide better - more than a factor of hundred higher current o Background seems negligible. o Overall detection efficiency under evaluation. o Extracting Pb from Na. I solved. Toni Wallner 26
Active Veto Slide from Francis Froborg 27
LNGS Proof of Principle Slide from Francis Froborg 28
Proof of Principle LNGS 29
Expectations Slide from Francis Froborg 30
Conclusions & Outlook Slide from Francis Froborg 31
SABRE Collaboration Thanks to Elisabetta Barberio, Francis Froborg, & Toni Wallner for providing material & slides. 32
SUPL – location & floor plan 33
- Slides: 33