- Chambers, C;
- Walton, T;
- Fairbank, D;
- Craycraft, A;
- Yahne, DR;
- Todd, J;
- Iverson, A;
- Fairbank, W;
- Alamare, A;
- Albert, JB;
- Anton, G;
- Arnquist, IJ;
- Badhrees, I;
- Barbeau, PS;
- Beck, D;
- Belov, V;
- Bhatta, T;
- Bourque, F;
- Brodsky, JP;
- Brown, E;
- Brunner, T;
- Burenkov, A;
- Cao, GF;
- Cao, L;
- Cen, WR;
- Charlebois, SA;
- Chiu, M;
- Cleveland, B;
- Coon, M;
- Cree, W;
- Côté, M;
- Dalmasson, J;
- Daniels, T;
- Darroch, L;
- Daugherty, SJ;
- Daughhetee, J;
- Delaquis, S;
- Mesrobian-Kabakian, A Der;
- DeVoe, R;
- Dilling, J;
- Ding, YY;
- Dolinski, MJ;
- Dragone, A;
- Echevers, J;
- Fabris, L;
- Farine, J;
- Feyzbakhsh, S;
- Fontaine, R;
- Fudenberg, D;
- Giacomini, G;
- Gornea, R;
- Gratta, G;
- Hansen, EV;
- Heffner, M;
- Hoppe, EW;
- Hößl, J;
- House, A;
- Hufschmidt, P;
- Hughes, M;
- Ito, Y;
- Jamil, A;
- Jessiman, C;
- Jewell, MJ;
- Jiang, XS;
- Karelin, A;
- Kaufman, LJ;
- Kodroff, D;
- Koffas, T;
- Kravitz, S;
- Krücken, R;
- Kuchenkov, A;
- Kumar, KS;
- Lan, Y;
- Larson, A;
- Leonard, DS;
- Li, G;
- Li, S;
- Li, Z;
- Licciardi, C;
- Lin, YH;
- Lv, P;
- MacLellan, R;
- Michel, T;
- Mong, B;
- Moore, DC;
- Murray, K;
- Newby, RJ;
- Ning, Z;
- Njoya, O;
- Nolet, F;
- Nusair, O;
- Odgers, K;
- Odian, A;
- Oriunno, M;
- Orrell, JL;
- Ortega, GS;
- Ostrovskiy, I;
- Overman, CT;
- Parent, S;
- Piepke, A;
- Pocar, A;
- Pratte, J-F;
- Qiu, D;
- Radeka, V;
- Raguzin, E;
- Rao, T;
- Rescia, S;
- Retière, F;
- Robinson, A;
- Rossignol, T;
- Rowson, PC;
- Roy, N;
- Saldanha, R;
- Sangiorgio, S;
- Schmidt, S;
- Schneider, J;
- Schubert, A;
- Sinclair, D;
- VIII, K Skarpaas;
- Soma, AK;
- St-Hilaire, G;
- Stekhanov, V;
- Stiegler, T;
- Sun, XL;
- Tarka, M;
- Tolba, T;
- Tsang, TI Totev R;
- Tsang, T;
- Vachon, F;
- Veenstra, B;
- Veeraraghavan, V;
- Visser, G;
- Vuilleumier, J-L;
- Wagenpfeil, M;
- Wang, Q;
- Watkins, J;
- Weber, M;
- Wei, W;
- Wen, LJ;
- Wichoski, U;
- Wrede, G;
- Wu, SX;
- Wu, WH;
- Xia, Q;
- Yang, L;
- Yen, Y-R;
- Zeldovich, O;
- Zhang, X;
- Zhao, J;
- Zhou, Y;
- Ziegler, T
The search for neutrinoless double beta decay probes the fundamental
properties of neutrinos, including whether or not the neutrino and antineutrino
are distinct. Double beta detectors are large and expensive, so background
reduction is essential for extracting the highest sensitivity. The
identification, or 'tagging', of the $^{136}$Ba daughter atom from double beta
decay of $^{136}$Xe provides a technique for eliminating backgrounds in the
nEXO neutrinoless double beta decay experiment. The tagging scheme studied in
this work utilizes a cryogenic probe to trap the barium atom in solid xenon,
where the barium atom is tagged via fluorescence imaging in the solid xenon
matrix. Here we demonstrate imaging and counting of individual atoms of barium
in solid xenon by scanning a focused laser across a solid xenon matrix
deposited on a sapphire window. When the laser sits on an individual atom, the
fluorescence persists for $\sim$30~s before dropping abruptly to the background
level, a clear confirmation of one-atom imaging. No barium fluorescence
persists following evaporation of a barium deposit to a limit of $\leq$0.16\%.
This is the first time that single atoms have been imaged in solid noble
element. It establishes the basic principle of a barium tagging technique for
nEXO.