# System Components

A typical Single Quantum EOS closed cycle single-photon detection system compromises the following:

- Cryostat with detectors and cold head.
- Air- or water-cooled compressor. The compressor provides high-pressure helium gas to the cold head and includes a cold head drive unit to provide power to the cold head motor. The environmental and electrical requirements can be found in the installation protocol (see appendix).
- Pressurized gas lines. The gas lines connect the compressor and the cold head. Helium gas is supplied from the compressor to the cold head and returned from the cold head to the compressor. A gas line is flexible and includes quick disconnect fittings on both ends.
- Atlas SNSPD driver that controls the detectors, reads the detector countrates and the temperature of the cryostat.
- Accessories: coaxial cables, DC Fischer cable, Ethernet cable, Usb to Ethernet adapter and power supply.

Optional components are:

- Turbo Pumping station.
- Polarization controllers.
- Housing rack.

In addition we advise the users to have an optical fiber cleaning kit and a fiber inspection microscope.