The 0.3K 3He sorption cooler with evaporator, sorption pump, connecting tube, and heat switches. All functional components are suspended from the (4 K) structural frame by Kevlar strings.

Photometer focal plane unit (QM) with the two bolometer assemblies (short-wave/long-wave)and the 0.3 K sorption cooler.

Micrograph of one pixel of the filled bolometer array development model next to a photo of the 16 × 16 pixels subarray. The physical size of a PACS pixel is 0.75 mm. The absorber and back-reflector grids as well as the integrated thermistor are monolithic silicon structures. 4 × 2 subarrays form the focal plane of the short-wave bolometer assembly. The 0.3K multiplexers are bonded to the back of the subarrays. Ribbon cables lead to the 2 K buffer electronics.