Documentation/Control Process for the LH2 Target Drawings
This is a summary of the procedures followed at IUCF regarding the control and signing of drawings for components of the NPDGamma LH2 target. The drawings themselves are posted in pdf form at The people involved in this process were Bill Lozowski, IUCF target/cryogenic designer and overall coordinator of the IUCF LH2 target project, Walt Fox, IUCF mechanical designer, Hermann Nann, professor of physics, and Mike Snow, professor of physics. Bill Lozowski was responsible for the official approval at all steps of the process at IUCF and was responsible for official communications with vendors.
(1)The first version of the Al and Ti target vessels and the main vacuum system drawings generated by Walt Fox were produced as bid packages for vendors to guide price quotations handled by the Indiana University purchasing department. These drawings were reviewed by Bill Lozowski, Hermann Nann, and Mike Snow and approved for inclusion in the bid packages by Bill Lozowski. The designs were chosen to meet the goals of the experiment and to satisfy the requirements of LH2 safety as outlined in broad terms in earlier recommendation of the NPDGamma LH2 safety committee.
(2)The vendors either quoted the job as specified or suggested what they considered to be equivalent changes. Lozowski, Fox, Nann, and Snow evaluated the bids and considered whether or not the suggested changes were still consistent with the experiment and safety goals. A vendor was selected.
(3) After selection of a vendor, more detailed feedback from vendor on alternate
suggestions/procedures/fabrication processes for the component were discussed. We then interact with vendor and the NPDG LH2 change control committee if necessary and either approve or disapprove the suggested changes before fabrication. The criterion used to request a change control to this committee were significant deviations from the conceptual design of the system as presented at the last review of the NPDG LH2 target safety. A next version of the drawings is generated at this stage before fabrication by the vendor.
(4)Vendor starts job and informs IUCF of any further suggested changes outside the scope of that might make fabrication easier before they are performed (an explicit requirement in the bid packages). Once again we either approve the modification or not and/or make a change control request if warranted. Modifications to the drawings are made again as required based on the accepted changes.
(5)When the finished component from the vendor arrives at IUCF, we verify by direct inspection that the objects conform to the latest version of the drawings and make any additional changes. At this point the drawings are the final, as-made drawings. Bill Lozowski approves the drawings by signing a hard copy kept at IUCF and also by initialing the pdf versions of the drawings available on the website.