Vacuum and cryogenic product supplier Helix Technology Corp. of Mansfield, Mass., has agreed to acquire IGC Polycold Systems Inc. of Petaluma, Calif., for $49.2 million in cash and up to $3.3 million in transaction-related tax payments. IGC, a subsidiary of Intermagnetics General Corp., produces high-speed water vapor cryopumping and cryogenic cooling products. The arrangement will extend the offerings and marketing reach of Helix's CTI-Cryogenics, which, together with its Granville-Phillips operations, provides components and subsystems that are used in the production of semiconductors, flat panel displays and data storage devices. Subject to customary closing conditions, the acquisition is scheduled for completion this quarter.