Ms
Mouli Chaudhuri
(School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050, India and Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India)
Radioactivity-induced backgrounds are one of the major sources of backgrounds for rare event search experiments like direct detection of Dark Matter, Coherent Elastic Neutrino Nucleus Scattering (CE$\nu$NS), and Neutrinoless Double Beta decay (NDBD). Measurement of these backgrounds and their reduction is crucial for these experiments. We will discuss the fabrication and performance of a newly developed annular cryogenic phonon-mediated active veto detector which allows a substantial reduction of radiogenic backgrounds. In SuperCDMS SNOLAB, three of the major backgrounds that may limit the sensitivity, are Compton scatters, surface $\beta$ decays from detector housing, and background from $^{210}$Pb recoil already existing on the detector surfaces from Radon exposure. The active veto detector hosting an inner target would eliminate almost all the backgrounds from surface $\beta$s and the $^{210}$Pb recoils and reduce the Compton background by one order of magnitude.
The active veto detector is designed in such a way that it can host an inner target detector. A germanium based $\sim$500 g active veto detector is fabricated with an outer diameter of 76 mm, inner diameter of 28 mm, and 25 mm thickness. The $\sim$10 g inner detector made of germanium is 25 mm in diameter and 4 mm in thickness. A GEANT4 based simulation is performed with the active veto and inner target detector which shows that the background rate can be reduced by 50 - 80\%. Further background reduction ($>$ 90\%) is achieved with 4$\pi$ veto coverage done by placing two germanium detectors with 76 mm diameter and 25 mm thickness at the top and bottom of the veto detector. The active veto detector assembly with 4$\pi$ coverage was placed at the MINER (Mitchell Institute Neutrino Experiment at Reactor) site. The comparison of experimental data with simulation shows excellent agreement.
Ms
Mouli Chaudhuri
(School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050, India and Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India)
Dr
Andrew Jastram
(Department of Physics & Astronomy, Texas A&M University, College Station, TX 77843, USA)
Prof.
Glenn Agnolet
(Department of Physics & Astronomy, Texas A&M University, College Station, TX 77843, USA)
Dr
Samir Banik
(School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050, India and Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India)
Dr
Hao Chen
(Department of Physics & Astronomy, Texas A&M University, College Station, TX 77843, USA)
Dr
Vijay Iyer
(School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050, India and Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India)
Dr
Varchaswi K. S. Kashyap
(School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050, India and Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India)
Dr
Andy Kubik
(SNOLAB, Creighton Mine #9, 1039 Regional Road 24, Sudbury, ON P3Y 1N2, Canada)
Mr
Mathew Lee
(Department of Physics & Astronomy, Texas A&M University, College Station, TX 77843, USA)
Prof.
Rupak Mahapatra
(Department of Physics & Astronomy, Texas A&M University, College Station, TX 77843, USA)
Mr
Sandro Maludze
(Department of Physics & Astronomy, Texas A&M University, College Station, TX 77843, USA)
Prof.
Nader Mirabolfathi
(Department of Physics & Astronomy, Texas A&M University, College Station, TX 77843, USA)
Ms
Nityasa Mishra
(Department of Physics & Astronomy, Texas A&M University, College Station, TX 77843, USA)
Prof.
Bedangadas Mohanty
(School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050, India and Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India)
Dr
Himangshu Neog
(Department of Physics & Astronomy, Texas A&M University, College Station, TX 77843, USA)
Mr
Mark Platt
(Department of Physics & Astronomy, Texas A&M University, College Station, TX 77843, USA)
