1 / 19

Background Reduction Techniques in Neutrinoless Double Beta Decay Experiments

This study delves into the challenges of background reduction in Neutrinoless Double Beta Decay (NDBD) experiments, emphasizing the critical role of careful detector design. Key methods include employing cosmic veto shielding, utilizing underground locations, and constructing detectors with low-background materials like electroformed copper. The research examines the sources of background radiation, such as environmental gamma radioactivity, neutrons, and radon. It further explores the enrichment of DBD elements and the necessity of minimizing cosmogenic activation effects to enhance sensitivity and achieve experimental goals.

aderes
Download Presentation

Background Reduction Techniques in Neutrinoless Double Beta Decay Experiments

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. Background Study in NDBD Ming Shao

  2. sources • environmental gamma radioactivity • cosmic rays • Neutrons • Radon • contamination of materials which detectors and their shielding are made of • …

  3. methods • 􀂾 Cosmic veto shielding • 􀂾 Underground locations • 􀂾 Detector construction using screened low-background materials • 􀂾 Detector construction using electroformed copper • 􀂾 Ultra-pure shielding materials • 􀂾 Low-cosmic-ray exposure DBD material, and copper … • 􀂾 DBD element enrichment • 􀂾 Signal processing • 􀂾 Detector segmentation • …

  4. Example: Majorana • Germanium crystals • Electroformed copper module • Close-in part • Thick shield of lead • Neutron-absorbing blanket • Active cosmic-ray veto shield

  5. Background model • Critical to the design and execution of the NDBD experiment • Guide the pre-commissioning efforts in detector • Acquisition system design • Sensitivity calculation -> physical goal • Depend on experiment method • Combine empirical and theoretic data

  6. Background reduction in Majorana • Ge background • Cosmogenic backgrounds in Ge • Neutrons at Altitude • Enrichment • Primordial (Potassium, Uranium and Thorium) • Backgrounds in Cu • Cosmogenic Activities in the Copper • Backgrounds in Pb • Other Materials

  7. Cosmogenic backgrounds in Ge

  8. Neutrons at Altitude - rate calculation

  9. Cosmogenic activation stages

  10. Primordial radioactivity • Uranium-238 • Thorium-232 • (Polonium-210) • Characteristic Alpha peak can be used for background estimation

  11. Cu • superior material for ultra-low background • Cu electroplating • Cosmogenic activation • Natural activities (208Tl and 214Bi)

  12. Pb • Gamma reduction • Ultra-low background Pb in inner detector • Normal lead outside

  13. Other materials • Outer: low dust situation to prevent contamination of the inner shield during maintenance • Inner: thermal insulators and structural parts (plastic), wires, electrical contacts (metalized plastic), and vacuum seals (indium) • Commercially purchased • screened and stored

  14. |<m>| ~35 meV

More Related