The HL-LHC upgrade necessitates radiation hardness improvements of inner tracker pixel
sensors and provides opportunities to leverage improvements in silicon manufacturing technologies.
A primary indicator of radiation hardness is sensor efficiency after irradiation. To measure sensor
efficiencies for the HL-LHC upgrade, a pixel telescope was constructed to use betas from Ru-106 and
Sr-90 sources for DUT analysis in place of a test beam. Stringent cooling requirements of irradiated
sensors necessitate the use of a heat sink, so the DUT is placed at the bottom of the telescope.
This demands a robust statistical analysis to produce useful results. Thus, a MC model of the
telescope was developed and used to generate PDFs of multiple Coulomb scattering angles. These
PDFs are used to calibrate a separate analysis package which gives expected numbers of hits within
certain probability intervals. By comparing the expected and measured hits in a given threshold,
an efficiency is obtained. This method is still in the development phase, but shows significant
promise when applied to simulated data generated via the MC model and can accurately measure
efficiencies of simulated DUTs with uncertainties of 5% or less.</p
