The physics program in Hall A utilizes a number of different target systems of varying complexity. There is a set of cryogenic targets which currently operates with hydrogen and deuterium as target materials and will soon support both helium 3 and helium 4.
A variety of solid targets is also provided; Be0, Carbon or Kapton are typical but other self supporting materials are available if need arises.
The combination of cryogenic targets and a few solid targets is the standard configuration. In addition, there is a large program based on polarized helium 3. This is a special installation and hence is not available at the same time as the cryogenic target system.
Finally, a waterfall target was used during the commissioning of the hall and is still available as a resource. This system also requires a special installation.
Each of these systems is discussed in this chapter or in an appendix.