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ISIS Direct Inelastic Data Reduction

Inelastic data reduction is the process of transforming data obtained in inelastic scattering experiment into the data, describing inelastic cross-sections of the processes under investigation.

To process the data recorded by Direct Inelastic Instruments and obtain the desired cross-sections ISIS scientists use the Mantid-based reduction program with a range of additional data and set-up parameters, tuning up this program to the particular inelastic instrument and experimental conditions. Users are also provided with access to the computing cluster, dedicated to help them in processing raw experimental data into the form, which has physical meaning.

From a user's point of view, the processing of their results should be simple and straightforward, namely:

1. User logs into his or her isiscompute account with logon name and password, obtained from user office and should see a folder with the RB-name of the proposal, approved for the experiment.
2. In this RB folder user can find a python script, necessary to process the raw results of the experiment. He or she opens this script im Mantid, change the run numbers to the numbers obtained in the experiment, may change some reduction parameters familiar to him, and processes the results of the experiment. User should not need to set up Mantid or modify the advanced reduction parameters.
3. In their account user should also find links to sample Horace and Mantid scripts to provide further analysis of their data.

The details of services, resources and Mantid settings necessary to allow users to process their data, are provided on the pages below:

Setting up Mantid, Matlab and auxiliary programs to process results of inelastic experiments. User should familiarise himself with this information if he is going to set up and process data on his personal machine.

When autoreduction service is enabled and set up propertly, users data are also processed automatically, namely:

1. Within RB folder a user finds folder named autoreduction. The folder should contain the reduced data processed automatically by autoreduction service, which runs on a separate powerful machine and picks up the results of the experiments as they are completed and rapidly reduces them using a script similar to the one the users have in their RB folder.
2. If necessary and convenient, the users should be able to change some parameters and reprocess some or all their runs using the web-interface and autoreduction service.
3. The common part of raw data processing (e.g. generation of the sqw files) can also be delegated to the autoreduction service.

The autoreduction service is currently working in test mode, so its availibility and reliability are not guaranteed.

Short description of the scripts, used to process results of the inelastic experiments in ISIS can be found here:

ISIS direct reduction script description.

Reference material containing information about choppers, used by ISIS inelastic instruments, necessary for chopper flux&resolution calculations is provided below:

Chopper Parameters

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