The Belle II detector

is a general purpose spectrometer for the next-generation B-factory experiment at KEK. The Belle II efficiently collects data of e+-e collisions made by the SuperKEKB accelerator. The Belle II consists of several sub-detector components:

  1. two layers of pixelated silicon sensors (PXD) and four layers of double-sided silicon strip sensors (SVD) that measure decay vertex positions of B mesons and other particles,
  2. a central drift chamber (CDC) that measures trajectories, momenta and dE/dx information of charged particles,
  3. a barrel-shaped array of Time-Of-Propagation (TOP) counters that reconstruct, in spacial and time coordinates, the ring-image of Cherenkov light cones emitted from charged particles passing through quartz radiator bars, another ring-imaging Cherenkov counters with aerogel radiator in the forward end-cap (A-RICH),
  4. an electromagnetic calorimeter (ECL) comprised of scintillator crystals located inside a superconducting solenoid coil that provides a 1.5 Tesla magnetic field, and
  5. an iron flux-return located outside of the coil which is instrumented to detect K0L mesons and to identify muons (KLM).

There are other tasks essential for the detector:

  1. a fast and reliable trigger (TRG) and data acquisition system (DAQ) records collision events of interest,
  2. stable operation of superconducting solenoid magnet,
  3. a globally-distributed computing and data-storage system and organized effort on various levels of software that work on the computer (Soft/Comp),
  4. an arrangement of components around the Interaction Region (IR), such as beam pipes and final focusing magnets, which directly impacts the amoung of beam backgrounds, and
  5. an integrated effort on the mechanical structure design (STR).

You may find more details in the internal page for detectors.