Systems, reagent support trays, particle suppression devices, and methods are disclosed. In one aspect, a system includes a vaporizer vessel having one or more interior walls enclosing an interior volume and a plurality of reagent support trays configured to be vertically stackable within the interior volume. Each of the plurality of reagent support trays is configured to be vertically stackable within the interior volume to form a stack of reagent support trays. One or more of the plurality of reagent support trays is configured to redirect a flow of a gas passing between adjacent reagent support trays in the stack of reagent support trays to cause the flow of gas to interact with the source reagent material in a particular reagent support tray before passing into a next of the plurality of reagent support trays in the stack of reagent support trays.