A mass spectrometer comprises an ion source which produces an ion beam from a substance to be analysed and a detector to detect a quantity of ions incident thereon. One or more source register address values are compared with one or more current values generated from a first iteration of a loop, and upon determining that one ore or more values in the source registers are the same as one or more current generated values, floating point register file reads of the equal values from the one or more source registers are inhibited. In some embodiments, lenses are positioned between the heat source and the substrate to focus or diffuse radiation from the heat source and thereby selectively alter the radiation intensity incident on certain portions of the substrate. These alerts may be characterized as including multimedia information and they may be prefer to play conveyed to membership with whom the underlying data is associated. In response to the access control policy prohibiting disclosure of the requested customer data, the method includes denying the customer data query. The present invention provides, according to the transmission characteristic of the existing HSDPA multi-carrier, a method for allocating downlink traffic channel resources, which method is applicable for packet data transmission of the multi-carrier HSDPA.