This thesis will explore the theory and design of a novel variant of the superconducting nanowire single photon detector (SNSPD). This new detector is dubbed the Superconducting Delay Line Detector (SCDLD) and is designed to enable the scaling of SNSPDs to unprecedented sizes while also adding the ability to discern the position of detected particles. The detection mechanism of the SCDLD is essentially identical to that of the SNSPD; a superconducting wire is biased near its critical current. When an incident particle's energy is absorbed, the local critical current density is surpressed, causing the wire to revert to its normal state, generating a measureable voltage pulse. In the SCDLD, this wire is designed to operate as a microstrip rather than an inductor. Now, an ion event generates a pair of voltage pulses of opposite polarity which travel to opposite sides of the microstrip. By measuring the relative delay between their arrivals, it is possible to calculate where in the detector the event occured.

Because this detector architecture is substantially different from previous those studied in much of the SNSPD literature, careful attention will be paid to the dynamics of this detector system. In particular, the subject of latching is revisited, taking into account the new electrical system our detector comprises. Elements of the device physics which have not been thoroughly studied in the SNSPD literature will also be treated, such as the interaction of multiple interleaved detectors operating within close proximity to one another on a single die. In addition, the new capability of position discernment allows for unique methods of data collection and analysis compared to existing SNSPD work which will be studied extensively.

This new detector technology is developed with an eye towards applications in the field of materials' analysis. In particular, time of flight spectrometry of large biomolecules and atom probe tomography of myriad sample types are both interesting potential applications for these detectors. With these applications in mind, the work in this thesis is therefore geared towards the detection of ions which have energies of order 5 to 10 kiloelectronvolts.