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BT9 triple-axis neutron spectrometer

labeled photo of

The instrument on beam tube 9 (BT-9) in the thermal neutron confinement building at the NCNR is a conventional triple-axis spectrometer featuring PG(002) or Ge(311) monochromators. It receives flux from a 6 inch diameter tangential beam tube, which helps to reduce fast neutron background, and exits at the southwest corner of the reactor face. The main shutter control for BT9 is mounted on the south outside wall and can only be operated by contacting reactor operations (x6292). The user controlled local shutter control is mounted on the monochromator drum shielding to the left side of the beam exit from the monochromator drum.

CRITICAL SAFETY NOTE: The main beam is a HIGH-RADIATION AREA with exposures exceding 1 R, so that when the beam is ON (beam indicator at the top of the drum says ON) it is extremely important that all persons must remain out of the main beam path area. Infrared sensor alarms will activate in the case that anyone approaches the beam area with the beam ON. Any malfunction of these alarms requires that the beam must be immediately closed and the malfunction fixed. It is a requirement for the instrument to operate that the HIGH-RADIATION AREA extend to no more than 30 cm from the main beam line in any direction. This means that radiation levels may not excede 100 mRem beyond that distance. It is the user's responsibility to ensure that these radiation levels are not exceded.

SAFETY NOTE: Be aware of the Emergency Control Procedures posted at the instrument. ECP

Contacts

name office extension e-mail@nist.gov home phone
Ross Erwin A120 x6245 ross.erwin (301) 208-1674
Jeff Lynn A126 x6246 jeff.lynn (301) 424-3353
William Ratcliff A122 x4316 william.ratcliff (301) 869-4851

Recent Thermal Triple Axis Publications

Recent upgrades

Computer control

Data collection is handled by the ICP program, ICP

How does a triple-axis spectrometer work?

If you have a vrml plug-in for your browser vrml browsers , you can manipulate a model of a triple-axis spectrometer at VRML 3-axis spectrometer. Directions for this model are at VRML 3-axis spectrometer description

Sample environment

BT9 is equipped with a standard Huber double arc (+-23 degrees on each arc) goniometer which can handle a large selection of sample environment equipment. If you need to disconnect the cables to the motors that drive the goniometer arcs or translations, make sure that the motors are powered down first (e.g. ICP command to disable motor 7: md 7 ;and to enable motor 7: me 7) See ancilliary equipment

BT9 schematic top view

top view of the bt9 instrument

Instrument component specifications

    Collimations

Filters

Slits

Motor controlled horizontal and vertical slits can be placed on the X-rail before the sample position.

Last modified 14-August-2012 by website owner: NCNR (attn: )