Frequently Asked Questions
Before Your Venue
Proposal
How do I submit a proposal?
- To learn more about submitting a proposal for beam time, go to neutrons.ornl.gov/users.
- To submit your proposal, go to the proposal system.
When will I know my proposal has been accepted?
Answer will go here.
My proposal has been rejected, what to do next?
Answer will go here.
Samples
Can I bring my samples?
answer here
Can I leave with my samples?
answer here
During your Experiment
Where can I stay?
A few options are available off-site and on-site. Check the neutron.ornl.gov users page for more infos.
Data Analysis
How can I browse my data?
Using ONCat, you will be able to
- view your data
- view the metadata and get infos about such or such data set
- find an experiment using keyword
- More features coming soon
How can I get help analyzing my data?
Just contact Jean Bilheux to discuss your needs.
By going over your experiment together, Jean will show you how to run the current tools and will develop customed python notebooks if needed.
What are those 'jupyter notebooks'?
Where are my data and how can I access them?
The following tutorial will show you where are you data and how you can access them. Just go to How To > Access your data
I get a firefox error message when trying to start the jupyter notebooks on the analysis machine.
After double clicking the start jupyter icon, I get an Firefox error message telling me that I have another Firefox window opened.
The short way to fix that is by starting the Help me application.
Then go to the Desperate Actions
and click the Fix Firefox!
This should fix your issue and you should be able to start the jupyter notebooks now.
Where do I find ImageJ (or Fiji) on the analysis computer?
Just follow the following path to find and start ImageJ.
If you need to learn how to use ImageJ, check their tutorial
web site
How to cite our work?
- Use of CG1D beam line
- iMars3D
- iBeatles
Metadata of the images and their meaning
You can retrieve the metadata of your TIFF images using:
- ONCat
- the jupyter notebook list_tiff_metadata.ipynb. Check How To > Start the python notebooks
| Tag Name | Description |
| ImageWidth | The number of columns in the image |
| ImageHeight | The number of rows in the image |
| BitsPerSample | The number of bits per component (ie. 16-bits or 32-bits for each greyscale pixel in our case) |
| SampleFormat | Specifies how to interpret each data sample in a pixel (1 = unsigned integer) |
| SamplesPerPixel | The number of components per pixel (1 in our case, which is grey scale) |
| Compression | 1 = None |
| PhotometricInterpretation | 1 = Min is black |
| MakeStr | The detector manufacture (eg. 'Andor' or 'SBIG') |
| ModelStr | The detector model number |
| SoftwareStr | EPICS areaDetector |
Tags 65000 to 650009 have no name and are used for timestamps and a unique ID
| Tag Name | Description |
| 65000 | EPICS timestamp. The timestamp is made when the image is read out from the camera. Format is seconds.nanoseconds since Jan 1st 00:00 1990. |
| 65001 | Unique ID for the image. Always 1 for single image acquisition, and incrementing up for camera and CT scans. Should always match the ImageCounter value. |
| 65002 | EPICS timestamp (seconds part only) |
| 65003 | EPICS timestamp (nanoseconds part only) |
Scan Information
| Tag Name | Description |
| FileNameStr | The original file name part of the constructed file name (see below) |
| InstrumentStr | 'CG1D' or 'VENUS' |
| IPTS | IPTS Number |
| ITEMS | ITEMS Number |
| SampleDescStr | Sample description (user entered) |
| NotesStr | User notes |
| DataSetStr | '2D' or '3D' |
| DataAcqModeStr | 'White Beam', 'TOF-cold/thermal', 'Epithermal' or 'Monochromatic' |
| DataTypeStr | 'OB', 'Raw' or 'DF' |
Camera/Image Information
| Tag Name | Description |
| ExposureTime | Exposure time for the image (in seconds) |
| ExposurePeriod | Exposure period for the image (Exposure Time + Readout Time in seconds). Not relevant for single image exposures. |
| NumImages | 1= single image exposure (our normal mode of operation) |
| ImageCounter | Always 1 for single image acquisition, and incrementing up for camera and CT scans. |
| MinX | Min X pixel (0 for full frame images) |
| MinY | Min Y pixel (0 for full frame images) |
| SizeX | Size of image in X dimension (should be equal to the ImageWidth value) |
| SizeY | Size of image in Y dimension (should be equal to the ImageLength value) |
| Temperature | The setpoint temperature (in C) |
| TemperatureActual | The actual temperature read from the detector (in C) |
Motor Position & Scan Device
| Tag Name | Description |
| MotScanDeviceStr | 'Small Rot' or 'Large Rot' used for this CT scan (if we are doing a camera scan or single image acquisition, this is not relevant) |
| RotationActual | Actual position of the rotation stage used in the CT scan (or the previous scan if we are doing a camera scan or single image acquisition) |
| MotRotTable.RBV | Large rotation table actual position |
| MotRotTable | Large rotation table setpoint |
| MotSmallRotTable.RBV | Small rotation table actual position |
| MotSmallRotTable | Small rotation table setpoint |
| MotLiftTable.RBV | Lift Table actual position |
| MotLiftTable | Lift table setpoint |
| MotShortAxis.RBV | Short axis actual posiiton |
| ... |
TIFF File Header Example
TIFF Directory at offset 0x800008 (8388616) Image Width: 2048 Image Length: 2048 Bits/Sample: 16 Sample Format: unsigned integer Compression Scheme: None Photometric Interpretation: min-is-black Samples/Pixel: 1 Rows/Strip: 2048 Planar Configuration: single image plane Make: Unknown Model: Unknown Software: EPICS areaDetector Tag 65000: 837380408.136687 Tag 65001: 1 Tag 65002: 837380408 Tag 65003: 148080423 Tag 65010: FileNameStr:TiffHeaderTests Tag 65011: InstrumentStr:CG1D Tag 65012: IPTS:17255 Tag 65013: ITEMS:-1 Tag 65014: SampleDescStr:polarization test Tag 65015: NotesStr:polarization test Tag 65016: DataSetStr:2D Tag 65017: DataAcqModeStr:White Beam Tag 65018: DataTypeStr:Raw Tag 65019: ModelStr:DW936_BV Tag 65020: ManufacturerStr:Andor Tag 65021: ExposureTime:1.000000 Tag 65022: ExposurePeriod:5.451660 Tag 65023: NumExposures:1 Tag 65024: NumImages:1 Tag 65025: ImageCounter:1 Tag 65026: MinX:0 Tag 65027: MinY:0 Tag 65028: SizeX:2048 Tag 65029: SizeY:2048 Tag 65030: Temperature:-60.000000 Tag 65031: TemperatureActual:-57.830002 Tag 65032: MotScanDeviceStr:Small Rot Tag 65033: RotationActual:183.000132 Tag 65034: MotLiftTable.RBV:247.500452 Tag 65035: MotLiftTable:247.500452 Tag 65036: MotShortAxis.RBV:76.000000 Tag 65037: MotShortAxis:76.000000 Tag 65038: MotLongAxis.RBV:193.016000 Tag 65039: MotLongAxis:193.016000 Tag 65040: MotRotTable.RBV:182.996500 Tag 65041: MotRotTable:183.000000 Tag 65042: MotSmallRotTable.RBV:183.000132 Tag 65043: MotSmallRotTable:183.000000 Tag 65044: MotDetTable.RBV:200.000000 Tag 65045: MotDetTable:200.000000 Tag 65046: MotCameraVert.RBV:-51.699796 Tag 65047: MotCameraVert:-51.699796 Tag 65048: MotHoriTrans.RBV:28.000000 Tag 65049: MotHoriTrans:28.000000 Tag 65050: MotVertTrans.RBV:60.000000 Tag 65051: MotVertTrans:60.000000 Tag 65052: MotDiffuser.RBV:86.300000 Tag 65053: MotDiffuser:86.300000 Tag 65054: MotAperture.RBV:138.700000 Tag 65055: MotAperture:138.700000 Tag 65056: MotSlitVB.RBV:39.969938 Tag 65057: MotSlitVB:39.969938 Tag 65058: MotSlitVT.RBV:39.860484 Tag 65059: MotSlitVT:39.860484 Tag 65060: MotSlitHR.RBV:40.000000 Tag 65061: MotSlitHR:40.000000 Tag 65062: MotSlitHL.RBV:39.977781 Tag 65063: MotSlitHL:39.977781 Tag 65064: AndorCCDCooler:1 Tag 65065: AndorCCDTempStatusStr:Not stabilized at set point Tag 65066: AndorCCDPreAmpGain:0 Tag 65067: AndorCCDADCSpeed:2
Work With Us
Visiting Researcher Program
Minority Serving Institutions Partnership Program