The primary method of obtaining beamtime is through the CHRNS proposal system. Calls for Proposals are issued approximately twice a year. (Other methods of obtaining beamtime are also available)
Statistics from previous proposal rounds
The system functions through written reviews of proposals by expert referees. Normally, several reviews are sought for each proposal, using referees chosen by NIST staff. In addition, CHRNS scientists carry out reviews for safety and technical feasibility.
After satisfactory reviews have been obtained, the CHRNS Beam Time Allocation Committee (BTAC) rank-orders the proposals and assigns the amount of beam time to be allocated to each successful proposal for each experimental station. The BTAC meets twice a year to do this. The actual scheduling of experiments is carried out by CHRNS staff. The BTAC has primary responsibility for proposal review, and provides advice to NIST and CHRNS management on all aspects of facility operation.
The current BTAC membership is:
The instruments available to guest researchers through the CHRNS proposal system are as follows:
|CHRNS Ultra-Small Angle Neutron Scattering Instrument (uSANS)|
|CHRNS High-Flux Backscattering Spectrometer (HFBS)|
|CHRNS Neutron Spin-Echo Spectrometer (NSE)|
|CHRNS Multi-Axis Crystal Spectrometer (MACS)|
|CHRNS Very Small-Angle Neutron Scattering (vSANS)**|
|Other Instruments offered by NIST|
|Thermal Neutron Triple-Axis with Polarized Beam option (BT7)|
|Disk-Chopper Spectrometer (DCS)|
|Polarized Beam Reflectometer (PBR)|
|MAGIK Off-Specular Reflectometer (MAGIK)|
|Neutron Imaging Facility (NIF)|
Small Angle Neutron Scattering with Polarized Beam option (SANS) - 30 m (NG7)
|Small Angle Neutron Scattering (SANS) - 30 m (NGB)|
|Powder Diffractometer (BT1)|
*These instruments are partially supported by the National Science Foundation through its Center for High Resolution Neutron Scattering (CHRNS) at NIST. Publications that result from work on these instruments should include an acknowledgment of CHRNS support (details here).
**The CHRNS vSANS instrument is currently being commissioned. This means that it is not fully functional and we are still testing features. In this proposal round, we are offering 60 days instead of the eventual 90 days so that sufficient time is available to complete commissioning and solve problems as they are found. By applying for this time, you are agreeing to help with commissioning by providing feedback so that we can ensure reliable service in the future. All the instrument’s eventual capabilities may not be available. For example, we are working to resolve background issues with the high-resolution detector which is used to reach the lowest minimum Q. However, CHRNS vSANS has 2 position-sensitive 3He detectors each with about 2.5 times the area of our current detectors allowing a wider Q-range in a single measurement. There are also 3 options for wavelength spread: 1% (λ = 0.475 nm), 13% (variable λ using a velocity selector), and 35% (λ ≈ 0.5 nm). Most SANS sample environments are available. Within these constraints, we intend for you to get publishable data and we won’t schedule approved beamtime until we believe that this is likely.