Ron Ghosh, reghosh (at) gmail.com, November 2018
During the long shutdown 91-95 the changeover to Unix was initiated and all archived data were converted to ASCII and compressed. A standardised extensible layout was adopted for all instrument data. The VMS Datatrieve archival system was supeseded by a simple file-directory based system with data identified by year/cycle_number, instrument, and run number. As new data were acquired extracts were added to a simple catalogue in each directory. The ILL web tool IDA can search these catalogues using wildcards or more specific date or short-title (NOMEXP - 10 character) information. The variety of earlier data makes it more difficult to complete these catalogues. By searching the datafiles it is however possible to construct simple lists of contents. Prioritising instruments where such data remains exploitable, useful, and interesting, the links below lead to these lists. The data remain safely archived at the ILL to whom applications must be made for further access. Re-use of these data also requires inspection of the instrument log-books of the time to complement the limited metadata in the measurements now included in the current ASCII and HDF/NeXus data files.
List of number of cycles with data still available for ILL instruments 1973-91
Links lead to summary indexes for interesting data with historical or future value 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 d1a 3 4 6 5 6 6 5 5 5 4 3 3 5 5 3 6 5 1 TG powders d1b 6 6 6 6 5 4 5 3 5 3 5 4 5 6 5 1 TG powders d2 3 1 1 6 6 6 6 4 T powders d2b 2 2 3 4 5 6 5 1 T powders d3 1 5 6 5 1 H magnetic single crystal. d4b 3 3 6 3 1 H liquids d7 4 1 6 6 6 6 6 2 4 3 5 3 5 3 5 6 5 1 CG diffuse/magnetic d9 6 6 6 6 6 5 5 4 5 3 5 4 5 5 5 1 T single crystal d10 3 1 1 6 5 3 2 4 3 5 4 5 2 5 4 5 5 5 1 TG single crystal d11 3 3 6 6 6 6 5 6 4 5 4 5 3 5 5 5 6 5 1 CG SANS d15 3 4 2 5 3 5 4 5 6 5 1 T single crystal d16 3 3 3 4 3 4 4 5 6 5 1 CG membranes/fibres d17 1 6 5 6 6 5 5 4 5 3 5 4 5 6 5 1 CG SANS in1 3 1 4 5 4 4 4 4 5 4 5 3 5 2 5 5 5 1 H 3-axis inelastic in3 2 5 5 5 1 TG 3-axis inelastic in4 4 1 6 6 6 6 6 4 4 3 4 3 5 5 4 6 5 1 T thermal ToF inelastic in5 3 1 6 6 6 6 6 6 4 5 4 5 3 4 1 5 5 5 1 CG quasi-elastic ToF in6 5 4 5 3 5 1 5 5 5 1 CG quasi-elastic Tof in8 3 6 3 2 3 5 5 5 1 T 3-axis inelastic in10 5 5 6 5 1 CG micro-eV quasi-elastic in11 1 5 6 5 1 CG spin-echo in12 CG 3-axis inelastic in13 3 3 3 4 3 5 4 5 5 1 TG quasi-elastic in14 2 5 5 1 CG 3-axis inelastic in20 2 5 5 5 1 T 3-axis inelastic T thermal beam-tube TG thermal guide H hot source CG cold guide
At the Neutron scattering meeting in Gatlinberg in 1976, for the first time novel results from the ILL were presented by over 30 participants from the ILL. After a few years of operation the conventional instruments could match others around the world, primarly due to the high fluxes available at the ILL. Of major concern to the Americans especially was the range of experiments which had been performed mainly by university rather than Neutron institute members using the newly constructed instruments on the extremely high performance cold source.at the ILL. Prototype instruments had been constructed earlier on medium flux reactors but these bore invaluable fruit when developed and updated for use with the neutron guide-tubes at the ILL. Thus small angle scattering, a low resolution technique with huge dynamic range, and high resolution quasi-elastic scattering featured as experiments impossible to match in the USA. Novel data from this period prompted a complete change across the world in the range of problems covered by neutron scattering.
Early measurements concentrated on high resolution, hence long measuring times and small data volumes. Only with the 2eme Souffle (1978- ) were bigger detector arrays introduced and better control systems allowing faster experiments scanning temperature and external constraints, probing more configuration space. A description of data from the CARINE system for each instrument is given in the report ILL07BA01T (Barthelemy et al., 1973). For the NICOLE multichannel instruments there were few metadata in addition to counts. With the replacement project, NICOLE II, much was added and is described (with updates) in note ILL89GH3 (Ghosh,1982,1989). Annotated examples of these data reformatted as ascii files are given in each section.
SANS Small Angle Scattering D11 and D17
Here are annotated examples of these data files.
The D11 instrument (Schmatz, Ibel), a pinhole instrument with a 64x64 1cm pixel multidetector was a world beating instrument from its first operation. With up to 40m collimation distance and 40m distance from sample to detector, and neutron wavelengths from 4.5A to over 30A there was enormous demand from a wide range of experimenters. Each experiment usually included calibration information, hence these data, together with information from the logbooks, can still be examined with analysis software on current computers.
Single crystal diffraction D3, D8, D9, D10, D15
Here are annotated examples of these data files.
Most raw counts data were immediately treated to extract structure factors, hence there is very limited demand for raw data.
Here are annotated examples of these data files.
The count-angle information remains easy to exploit, hence there remains real value in these data covering a wide number of experimental fields.
Diffraction from liquids and glasses D4
Here are annotated examples of these data files.
Isotope substitution to resolve partial structure factors required an instrument with extremely high long-term stability (Chieux) to allow the comparison of the different isotopic compositions.
3-axis inelastic scattering measurements IN1 IN2 IN3 IN8 IN12 IN14 IN20
Here are annotated examples of these data files.
The highly selective scans in (Q,omega) were chosen to test specific models for the large single crystals investigated. There was little post-processing of these data.
High Resolution Quasi-elastic scattering IN5, IN10, IN6, IN11, IN13
Here are annotated examples of these data files.
These instruments made possible the measurement of slow relaxation processes in polymers in bulk and solution. Fundamental liquid properties of the linewidth of the 4He roton were performed, and liquid 3He dynamics were measured for the first time. Molecular reorientations in plastic and liquid crystals too were measured extensively.
Other Time of Flight instruments, D7, IN4, IN7
These were used in magnetic diffuse scattering, molecular spectroscopy, including adsorbed species, and crystal field energies. The latter two were challenged by instruments developed later on pulsed sources.
The fission fragment spectrometer, Lohengrin, the three gamma-ray spectrometers, and BILL, the conversion electron spectrometer were used to study nuclear structure and nuclear energy level schemes.
Re-reading the early data archive
A few notes are included here on re-reading the PDP-10 tape images which were copied to CDROM on the VMS systems. The ILL utility SPECTRA (Blanchard, 1986) used DEC-datatrieve based software archive data for treatment (and was the source of the most of the ascii archive, Only the CDROM disks remain, mostly readable. Data from the PDP11 and VMS epochs are in 512 byte records, and can be read fairly easily even on linux. The early data was from a 36 bit computer, writing in 5 byte words, so there are a few more hurdles to recover certain data which were missed by SPECTRA. .