Neutron Sciences Directorate

Announcements

POWGEN has a partnership with beam line 11BM at the Advanced Photon Source where users can get x-ray data if they have an approved proposal at POWGEN.  This option is not available for mail in proposals.

Useful Links for POWGEN Users 

• POWGEN Experiment Guide: A–Z
• POWGEN Hutch Poster
• POWGEN Mail In Program Guide
• POWGEN Monitor Webpage
• POWGEN Rebuild paper Journal of Applied Crystallography, 52, 1189-1201 (2019)
• POWGEN Original paper Zeitschrift fur Kristallographie, 1, 127-135 (2011)
• POWGEN User Manual for Data Acquisition
• POWGEN User Manual for Data Reduction

Shipping Addresses for Samples 

Please visit the ORNL User Facilities Sample Handling and Shipping page.

Quick Start Guides for Sample Changes and Shutter Operation

• Gas-flow furnace sample change
• Vacuum furnace sample change
• Janis cryofurnace with high temperature stick (30-750 K) sample change
• Janis cryofurnace with low temperature stick (5-500 K) sample change
• Orange cryostat sample change
• PAC sample changer loading
• Removing Samples from Beamline 11a
• Shutter operation

Data Reduction and Analysis by Run Cycle

Parameter files for GSAS, GSAS-II, FullProf, Jana and TOPAS can be downloaded from the table below. Be sure to pick the correct cycle. These files are also stored in the /SNS/PG3/run_cycle_11A_CAL folder in the analysis computer where cycle is year_1 or year_2 based on cycle A or B.  

Data will be automatically reduced into the following formats:

• Extension .gsa for GSAS and GSAS-II: Files are numbered with banks which correspond to the wavelength used. Please use the corresponding bank # from the parameter files for refinements.
• Extension .dat for FullProf and Jana: The data file names themselves tell you which bank they are and the same bank IRF file should be used for FullProf.
• Extension .xye for TOPAS:  Please refer to the TOPAS example below.

Data Analysis Tutorials

• Mantid Tutorial - Finding Structural Change from Event Data
• FullProf refinement example
• GSAS/EXPGUI refinement example
• GSAS-II joint X-ray/neutron refinement using 11BM and POWGEN data
• TOPAS refinement example

How to access POWGEN data

Step by step instructions are also provided in the document POWGEN_Data_Access_User_Manual.

1. Create an ORNL Resource account (if you don’t already have one) at the ORNL Guest Portal. 
2. Once you have an account, you can login to our analysis cluster by clicking on Launch Session at https://analysis.sns.gov. Alternatively, you may install the ThinLinc client on your local machine.
3. Once you login, under your home directory you will see the following folder structure /data/SNS/PG3/IPTS-#/. All the run numbers will appear for your data. (Alternatively, you can find your data in /SNS/PG3/IPTS-#/shared/autoreduce.)  Your automatically reduced data can be found in the /shared/autoreduce folder, along with a summary file called PG3_IPTS-xxxxx_runsummary.csv.
4. Secure ftp or secure shell (SSH) will allow you to copy the data to your local drive. Select one of the programs below to download and install: FileZilla or Cyberduck.
        Enter the following information to connect to the analysis computers:
             Host: analysis.sns.gov
             Your username and password
             Port: 22