Computing at SSRL: Experimental User Support Timothy M. McPhillips Stanford Synchrotron Radiation Laboratory

What Happens at SSRL? Scientific Research in a Wide Range of Disciplines 26 experimental stations running on 10 insertion devices. Basic research in X-ray Physics, material science, structural biology, molecular environmental science, and other fields. Development of new techniques using synchrotron radiation. Over 200 publications in scientific journals from research at SSRL yearly. 136 Ph.D. theses in last five years, 54 from Stanford. Nearly 1600 Researchers Use the Facility 169 institutions in 36 states and 20 foreign countries represented. Typical visiting group involves 4-8 scientists. Typical beam time allocations range from a few hours to a few weeks. Majority of users are not collaborating with SSRL staff scientists. SSRL Staff Support the Experimental Users Design, construct, and maintain experimental stations. Train and assist users in use of the stations. Provide a powerful and convenient computing environment. Respond quickly to problems and changing user needs.

“Typical” Computing Environment at a Beam Line CAMAC Systems for Beamline Control and Data Acquisition Stepper motors for moving beam line optical elements, experimental apparatus, etc. controlled by CAMAC based motion controllers. CAMAC modules used for data acquisition. Grand Interconnect from Kinetic Systems used to control daisy-chained CAMAC crates from a single workstation at each beam line. A Single Computer is Required at each Beam Line Hosts Grand Interconnect PCI card. Runs motion control and data acquisition software. Processes and analyzes data. DEC Alpha Running OpenVMS is the Standard Platform Robust, secure operating system with performance characteristics appropriate for hardware control. Motion control and data acquisition software written at SSRL designed specifically for VMS.

A Protein Crystallography Beam Line Distributed Control System Standard VMS/CAMAC solution used for most stepper motors in beam line. DC and stepper motors controlled by PC cards (ISA/CompactPCI) used in experimental station. Distributed Control System (DCS) consolidates beam line control over network. Unix Platforms Required Commercial detectors and data collection software require Unix. Crystallographic data processing and analysis software run only under Unix. Dual Platform of Digital Unix and Silicon Graphics Workstations Favorite environment of protein crystallographers. Alphas provide maximum CPU performance while SGIs provide high-end graphics capability with real time video capture, distribution, and storage. Shifting towards unified user interface under IRIX with hidden multiprocessor DEC Unix machines for intense data processing.

Computing Resources at Beam Line 9-2

Staff Computing and OS Integration Large Number of Computers in Staff Offices Windows NT and Macintosh computers ubiquitous. Workstations running OpenVMS or Unix are common in staff scientists’ and software developers’ offices. Common Computing Resources Managed by SSRL Computer Group OpenVMS server “SSRL” provides mail services for everyone and user environment for VMS users. Windows NT servers define the SSRL domain. 100 BT switched network links all computers. Plans for Gigabit network upgrade in near future. Protein Crystallography Group Integrating Disparate Platforms Cluster of 15 Unix computers including beamline machines. User accounts and home directories unified with NIS and NFS. Advanced Server for Digital Unix (ASDU) used to export Unix home directories to Windows NT desktop machines. Wincenter provides NT environment on any X-Window capable display, unification of NT and NIS user accounts, as well as common home directories between Unix and NT.

Network and Collaborative Computing Two Web Servers Important for User Support Communication with users. Online forms for beam-time proposals, end-of-run summaries, etc. Documentation of beam line hardware and experimental techniques. Software manuals and tutorials. Network Connections with Home Labs Critical to Users at Beam Line Users at beam lines are subset of scientists participating in the research. Personnel at home labs often process and analyze newly collected data. Data is transferred by FTP home directly from data collection computers. Protein Crystallography Group Developing Collaboratory A collaboration with SDSC and Cornell MacCHESS with four years of funding for additional hardware and three new SSRL staff members. Development of collaborative, multi-user versions of crystallographic data collection, processing, and analysis software. Continuous video communication between beam lines and home labs. Long term storage of crystallographic data. Users will be continuously consulted throughout the development to ensure collaboratory’s success.