Envelope and multi-slit emittance measurements at Fermilab A0 photoinjector and comparison with simulations

Recently we have measured the envelope and the transverse emittance of an 0.85 nC electron beam at the Fermilab A0-Photoinjector facility. The transverse emittance measurement was performed using the multi-slit method. The data have been taken with an unstacked 2.8 ps laser pulse. In this paper we report on these beam measurements and compare the results with the predictions from beam dynamics codes ASTRA and GPT using 3D space charge routines