This website is being migrated. In case you don't find the information you are looking for, the old website can be found here. Thank you for reporting any anomalies to communication@ill.eu.
Switch instrument:
Tour virtuel
D11 Lowest momentum transfer & lowest background small-angle neutron scattering instrument

Upgrades and examples

Collimation renewal project (2001-2004)

Picture_diaphragm_changers.jpg

With 3 new collimation distances (1.5m, 28m and 34m), 6 new diaphragm changers, new mechanics including a complete re-alignment and the modifications at the selector area, the instrument has considerably gained in:

  • performance 
  • resolution
  • flexibility
  • reliability

For instance, a flux gain of ≈ 10 is obtained for certain experimental conditions.

D11 old detector small.png

New detector and tank project (2005-2008)

The future scientific requirements are calling for an innovative evolution of the instrument with a “best possible” specification, in order to strengthen ILL’s leading position in small angle scattering and maintain D11 as one of the world-wide most powerful and versatile SANS instruments. Consequently, the project of developing a faster and larger SANS detector has started in 2005, in the framework of the ILL’s Millennium Programme. 

The present 3He detector will be replaced by the 3He - MWPC 128x128-7.5 (the former CERCA 3He detector of D22). This detector has a considerably larger counting area thus a much better dynamic range, a better efficiency and a better spatial resolution. After some modifications of the detector electronics, the maximum possible countrate can be increased to about 300 kHz, i.e. a factor of 6 higher than the present D11 detector. The detector shall be installed in a new tank with an extended length and larger diameter. In conjunction with the enhanced counting area, the tank elongation will considerably increase the totally available Q-range of the instrument and allow for measurements at significantly lower Q-values than possible at present. Furthermore, it is planned to implement in the future a multi-hole imaging USANS option, thus challenging new frontiers in space and time resolution.

neutron_delivery_guides_visual_inspection.jpg

Guide replacement (2006-2008)

Following the review and analysis of the D11 guide system by McStas simulations in late 2005/ early 2006, an innovative guide design change had been decided in spring 2006. Significant flux gains can be predicted for a large range of collimation distances with a new widened glass guide with an opening 6.5m trumpet (30mm->45mm width) at the collimation entrance and a focusing trumpet at the collimation exit, near to the sample position
(see Lieutenant K., Lindner P., Gähler R. (2007) J. Appl. Cryst. 40, 1056 - 1063). 
In June 2006 the guide replacement project has been approved and coupled with the "new detector & tank" projcet to result in the extended Millennium project “D11 Revised”.