The POLARBEAR-2 and the Simons Array Experiment
  We present an overview of the design and status of the \Pb-2 and the Simons
Array experiments. \Pb-2 is a Cosmic Microwave Background polarimetry
experiment which aims to characterize the arc-minute angular scale B-mode
signal from weak gravitational lensing and search for the degree angular scale
B-mode signal from inflationary gravitational waves. The receiver has a 365~mm
diameter focal plane cooled to 270~milli-Kelvin. The focal plane is filled with
7,588 dichroic lenslet-antenna coupled polarization sensitive Transition Edge
Sensor (TES) bolometric pixels that are sensitive to 95~GHz and 150~GHz bands
simultaneously. The TES bolometers are read-out by SQUIDs with 40 channel
frequency domain multiplexing. Refractive optical elements are made with high
purity alumina to achieve high optical throughput. The receiver is designed to
achieve noise equivalent temperature of 5.8~$\mu$K$_{CMB}\sqrt{s}$ in each
frequency band. \Pb-2 will deploy in 2016 in the Atacama desert in Chile. The
Simons Array is a project to further increase sensitivity by deploying three
\Pb-2 type receivers. The Simons Array will cover 95~GHz, 150~GHz and 220~GHz
frequency bands for foreground control. The Simons Array will be able to
constrain tensor-to-scalar ratio and sum of neutrino masses to $\sigma(r) =
6\times 10^{-3}$ at $r = 0.1$ and $\sum m_\nu (\sigma =1)$ to 40 meV.
