provisional
R. Ghosh, June 1995
The common data file format for presenting the resultant S(Q,E) data for both TOF and Back-scattering instruments was introduced in October 1987.
It is possible to add specific extensions to the data file which can be skipped by standard programs not capable of dealing with these additional fields.
1. Use of fixed length records allows data sets to be concatenated easily, and offers easy access to any individual spectrum, especially if a local directory is made up by scanning the data file initially.
2. At the start of each 'spectrum' the total number of 'lines' or records is stored aiding this search.
3. The spectrum is divided into sections. The number of lines in each section, and the total number of sections is also written in the first line of the spectrum (Zone0)
4. For the first few zones the data have well defined contents independent of the instrument
zone 0 NTOT,NZONE1,NZONE2,NZONE3,NZONE4,NZONE5,NZONE6,NDATA FORMAT(8I5) NTOT Total number of lines in spectrum including Zone0 NZONE1 number of line in Zone1 NZONE2 etc NDATA number of lines of S(Q,E) data zone 1 TITLE (minimum 1 line) FORMAT(40A1) Zone 2.1 ANGLE,E0,Q0,TEMPK,AMASS,ISYM FORMAT(1X,F6.2,F8.3,F8.4,F9.3,F6.1,I2) Zone 2.2 DELTAEN,DELTATAU,DELTAK ANGLE degrees - scattering angle E0 meV - incident energy Q0 A-1 - constantQ TEMPK K - sample temperature AMASS amu - mass of scatterer ISYM - 0 if not symmetrised -1 symmetrised S(Q,E) DELTAEN meV ) original step size in DELTATAU mmsec/m/channel) measurement DELTAK K ) Zone 3 not defined Zone 4 not defined ... Zone 7(data) EN,S,SER FORMAT(6X,*F9.5,E13.5,E12.4) EN Energy transfer (meV) S S(Q,E) mev-1 SER error in S(Q,E) * F9.6 etc for mocrovolt values The first six characters can contain instrument specific values on a point by point basis.