A method, system, and apparatus for interrogating a radio frequency identification tag population are described. The burst disk is a composite design constructed of a solid carbon graphite center surrounded by an integrally formed stainless steel ring. According to the first invention, cavitation is generated in a pulp suspension preferably by a liquid jet and the resulting fine bubbles are introduced into the pulp suspension to adjust the pulp suspension to a desired freeness by means of the impact force induced by collapse of the fine bubbles in a process for producing pulp.