Ionizing radiation is often used within medicine for diagnosis and treatments. Because ionizingradiation can be harmful to the body, it is important to know how it affects the tissue. Dosimetryis the study of how ionizing radiation deposits energy in a material. To measure how much ionizingradiation is deposited in the body, gas-filled detectors are often used. An ionization chamber isa type of gas-filled detector and exists in different shapes and sizes, depending on what kind ofmeasurements it is made for. Because ionization chambers are relatively expensive, it is often notpossible to buy one for each type of measurement that is to be done. This results in ionizationchambers being used for measurements they are not optimized for. This report evaluates thepossibility of 3D printing ionization chambers to make it easier to optimize them for specificmeasurements. The process included creating models of ionization chambers using CAD-software,slicing them and then 3D printing them. The 3D printed models were then brought to the SwedishRadiation Safety Authority for measurements. The ionization chambers were connected to highvoltage, and exposed to ionizing radiation in the form of high-intensity gamma-ray fields. Theoutput current of the ionization chamber was measured, which is proportional to the field intensity.The results were similar to those of a commercial ionization chamber. The conclusion is that it ispossible to 3D print ionization chambers. However, to get more accurate results, the design has tobe further optimized and more measurements need to be done.

Lab measurements and Monte Carlo simulations have been carried out for the evaluation of the Straw-type detectors used in the NA62 experiment at CERN. In addition, analyses of experiment data was used in corrections to improve the reconstruction of particle tracks, ultimately leading to improved resolution of the detector system as a whole. 97.7 percent of the Straws were aligned to within 30 microns, quantified as the deviation from zero of the mean of the inherent residual distribution of each Straw. A drift time dependence on where along the Straw the particle ionized have been corrected for; before the correction the dependence was as big as 6 ns. A radius-drift time relation based on the leading edge timing distribution has been deduced and implemented. Upon implementation artifacts from the piecewise fits used became evident. An alternative approach using residuals has been put forward.