1 / 17

Double Beta Decay With 20-ton Metal Loaded Scintillators A Detector for DUSEL?

Double Beta Decay With 20-ton Metal Loaded Scintillators A Detector for DUSEL?. Frank Calaprice Princeton University Aldo Ianni LNGS. The Borexino Detector. 14 C ~ 3 x 10 -18 U/Th <10 -17 85 Kr ~ 0.35 cpd/ton Cleanliness level 25 MIL-STD 1246C. General Idea (Similar to SNO+).

milica
Download Presentation

Double Beta Decay With 20-ton Metal Loaded Scintillators A Detector for DUSEL?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Double Beta Decay With 20-ton Metal Loaded ScintillatorsA Detector for DUSEL? Frank Calaprice Princeton University Aldo Ianni LNGS

  2. The Borexino Detector • 14C ~ 3 x 10-18 • U/Th <10-17 • 85Kr ~ 0.35 cpd/ton • Cleanliness level 25 MIL-STD 1246C

  3. General Idea (Similar to SNO+) • Use radiopurity MEASURED in the Borexino detector • Use preliminary data on Nd-loaded LS based on PC Goal: • Search for double beta decay with a 20ton-scale high purity LS detector • SNO+ proposal is for 1000 ton LS.

  4. Basic working assumptions: • T21/2 = 7 x 1018 yr • 50 meV neutrino mass (inverted hierarchy) • T1/2 = 1.2 x 1025 yr • Photon yield = 12000 / MeV (PC liquid scintillator) • QE = 0.35 (new high QE PMTs) • Coverage = 0.85 • Low radioactivity PMTs: ~ 30 mBq/PMT

  5. The Detector: basic idea FM

  6. Backgrounds: • PMTs + Steel Sphere ~ 40 Bq • 208Tl from nylon (<1ppt in Th) : • 0.861 MeV + 2.614 MeV ’s 12% BR • need to define FM • Radiopurity of nylon can be measured in CTF at ppt level or below. • Intrinsic Th in Scintillator: • Borexino 10-17 g/g gives ~ 1 c/yr around peak • Th coming with Nd ??? • Required ~ 10-15 gTh/gNd

  7. 1-kton SNO+ vs 20-ton scale detector: * Light absorption by Nd limits concentration **For comparison both detectors are assumed to have 50% PMT coverage.

  8. Natural abundance, 50 meV neutrino, 20-ton FM: 1 c/yr from nylon, ii) 1 c/yr from internal Th, iii) << 1 c/yr external Muon-induced activities above 3 MeV are short-lived and vetoed

  9. 50% 150Nd enrichment, 10 meV neutrino, 20-ton: • In 5 years the uncertainty in the measurement is 35%

  10. Breakdown of costs: • Add $3M for new purification system if LNGS • system is not used.

  11. Roadmap: • Measure radiopurity of nylon with present CTF • Preliminary tests of light propagation and energy resolution in small test chamber (~5 m3). • Rebuild CTF with Stainless Steel Sphere • Study Nd-loaded LS • Light propagation • Radiopurity • Energy resolution • Search for double beta decay at 50 meV sensitivity with CTF system. • Build larger (~50 ton LS?) system with optimum resolution/background for 10 meV at DUSEL?

More Related