Cleanliness and Materials
All components for user-supplied hardware that will be exposed to the NIF target-chamber vacuum will have to meet NIF cleanliness and vacuum compatibility. The materials and cleanliness of equipment or experimental assemblies, including target assemblies, that will be attached to or inserted into NIF are rigorously controlled to minimize possible damage to the laser optics from debris and to maximize the energy delivered to the Target Chamber by preventing contamination of the sensitive anti-reflective coatings used on lenses and other transmission optics. All materials and assemblies that are proposed for use on or in NIF must be reviewed and approved before they may be used. Prior to installation they must also be cleaned by NIF- approved cleaning vendors using special processes that ensure compliance with NIF cleanliness requirements.
Materials review and approval and relevant cleaning processes are communicated in a formal written NIF Materials Assessment issued on behalf of the NIF Cleanliness Steering Committee by its chairman, the Group Leader of NIF Operational Cleanliness. NIF Operational Cleanliness personnel conduct evaluations of materials and cleaning that are required as a part of the materials review and approval process and also provide oversight of clean rooms, cleaning vendors, and facilities in which clean assembly of equipment is performed to assure compliance with NIF cleanliness protocols. The Group Leader of NIF Operational Cleanliness is responsible for materials reviews and generally writes and issues the NIF Materials Assessments. In this capacity, the Group Leader for NIF Operational Cleanliness works directly with the responsible individuals (RIs) for systems and assemblies proposed for use on NIF to assure the completeness of the Materials Assessments and to arrange for any testing that may be required. The evaluation of complex assemblies can often require many weeks or months, so RIs are urged to begin the materials review early in the design process. The chairman is also a member of the Target and Laser Interaction Sphere (TaLIS, Section 3.3) Committee and in this capacity approves all target assemblies for materials and cleanliness. These approvals will not be granted unless a relevant NIF Materials Assessment has been completed and issued. For further information and to initiate a NIF Materials Assessment contact the current Group Leader for NIF Operational Cleanliness, William H. Gourdin, or the NIF User Office.