An apparatus is provided for reducing particle contamination in an ion implantation system. The apparatus has an enclosure having an entrance, an exit, and at least one louvered side having a plurality of louvers defined therein. A beamline of the ion implantation system passes through the entrance and exit, wherein the plurality of louvers of the at least one louvered side are configured to mechanically filter an edge of an ion beam traveling along the beamline. The enclosure can have two louvered sides and a louvered top, wherein respective widths of the entrance and exit of the enclosure, when measured perpendicular to the beamline, are generally defined by a position of the two louvered sides with respect to one another. One or more of the louvered sides can be adjustably mounted, wherein the width of one or more of the entrance and exit of the enclosure is controllable.