1. The Bifrost spectrometer
Very short update
Rasmus Toft-Petersen
Technical University of Denmark

2. The Bifrost spectrometer
Very short update
Rasmus Toft-Petersen
Technical University of Denmark

3. Outline: Changes since last STAP meeting
Fixed the analyzer design
Fixed the guide coating
Semi-fixed the chopper system design
Working hard on cave design, difficult
Monitors are the final scientific obstacle for guide tender

4. Outline

5. Analyzer geometry
We are going slightly out of Rowland geometry, but the geometry can be calculated anyway, to achieve roughly the same performance. The analyzer design couples to the tank design.

6. Analyzer geometry
5 mm margin to the cross talk shielding, which also serves to make us able to fix the design

7. Analyzer geometry
Simulated optimum exactly the same as calculated. We are in a good shape to fix the analyzers. Mounting method the only problem: Optimizing background. However, PSI are the experts in this.

8. Monitors problem 1
PSC chopper monitor might not make sense. The fast pulse almost overlaps with the slow one at 6 m. It takes 3 ms for the 2 km/s neutrons to travel to that monitor from the source. This monitor will be bathed in gammas, fast neutrons and slow neutrons at the same time.
Does it make sense to put another monitor in the bunker anyway? Should the first monitor just be outside the bunker?

9. Monitors problem 2
Overall intensity on Bifrost is 10^11 n/s/cm^2 distributed pseudo-continuously
Outside the bunker, the peak intensity will be larger by a factor of 5

10. Thank you for your attention