Position-sensitive Parallel Plate Avalanche Counters (PPACs)
Position-sensitive Parallel Plate Avalanche Counters (PPACs) are gaseous detectors that have been developed since the lates 90s and play a very important role detecting heavy ions for tuning of the beam production in fragment separators (where the ions are produced and selected) but also for rare isotope beam delivery lines to the scientists. One of the most important features of the PPAC detector is that the amount of substance seen by particles passing through it is quite small. Consequently, there is a significantly less perturbation in the production and delivery of rare isotope beams and they are durable with relatively easy maintenance because of their simple structure.
The PING students were tasked to build two 10 cm x 10 cm PPAC detectors over the course of one week from scratch. The work involved: handling and stretching a 1.5 um aluminized Mylar foil used for the cathode and anode as well as the gas windows, placing thin layers of cement and vacuum compatible glue to hold the foils onto FR4 boards and aluminum frames, solder ground and signal cables along with some resistors and capacitors.