Ji, Y. Spentzouris, L.K. Zwaska, R.M. JACoW Geneva, Switzerland 978-3-95450-180-9 10.18429/JACoW-NAPAC2016-THPOA45 English 1190-1193 THPOA45 ion electron vacuum proton operation Contribution to a conference proceedings 2017 2017-01 http://dx.doi.org/10.18429/JACoW-NAPAC2016-THPOA45 https://jacow.org/napac2016/papers/thpoa45.pdf Studies of in-situ Secondary electron yield (SEY) mea- surements of material samples at the Main Injector (MI) beam pipe wall location started in 2013. [2, 3] These studies aimed at understanding how the beam conditioning of differ- ent materials evolve if they function as MI vacuum chamber walls. The engineering run of the SEY measurement test stand was finished in 2014. From 2014 to 2016 the Fermilab accelerator intensity has increased from 24 × 10¹² protons to 42 × 1012 protons. The beam conditioning effect on SS316L and TiN coated SS316L has been observed throughout this period. [1] Improvement of the data acquisition procedure and hardware has been performed. A deconditioning pro- cess was observed during the accelerator annual shut down in 2016.