A study of readout electronics based on TDC for the international linear collider TPC detector

As a main tracking detector for the International Linear Collider, the Time Projection Chamber (TPC) is required to have good momentum resolution. High granularity readout would need a large number of complicated and expensive flash-ADCs. To achieve the desired packing density of the TPC readout electronics one needs to have at least an order of magnitude more compact solution than any existing one. We study an alternative method of the TPC data readout, which is based on a charge-to-time conversion technique and a multihit Time-to-Digital Converter (TDC). In our Proof-of-Principle experiment, we use the ASDQ circuit and a commercial multihit TDC. The possible use of TDC based readout electronics was demonstrated with an ultraviolet laser test setup. TDC based readout electronics might be an alternative solution for the new precise TPC. Inherently low data transfer would reduce cabling, thus simplifying the TPC end plate construction, weight and decrease the radiation length(X₀) of the TPC end plate.