UCN optics, polarization foils and spinflipper for the munich nEDM approach
Thorsten Lauer
2
Demands in UCN components
T.Lauer – EDM workshop Oak Ridge Oct.2012
UCN guides
UCN polarizer
UCN detectors
UCN storage cell
UCN spin guiding
SR6 exit
S-bend in UCN guide
UCN source
Biological shield
Neutron life-time experiment
Qbounce Reactor wall
Halle Ost
EDM
Phase space transformer
SC spin filter
3
28 m
UCN beam positions at FRM-2
T.Lauer – EDM workshop Oak Ridge Oct.2012
UCN optics infront of the EDM
SC magnet + spin flipper
4T.Lauer – EDM workshop Oak Ridge Oct.2012
EDM spectrometer is at the same floor level as the source
Manipulating the UCN spectrum
for nEDM: B0 ≈ 1.5 T RF frequency ≈ 40 MHz
to do: - building a spinflipper (birdcage resonator,…..?) - Ordering superconducting magnet
(length min. 600 mm, warm bore of 300 mm)
TneVBBV /3,600
5T.Lauer – EDM workshop Oak Ridge Oct.2012
Inside the EDM
UCN guides
UCN switch
Polarisation foil in front of the detector
UCN bend sections
6T.Lauer – EDM workshop Oak Ridge Oct.2012
UCN guides
New sputtering facility for UCN guides:
Coatings of NiMo,Cu, Ti, supermirrors… inside tubes- max. guide length 1.8 m- inner diameters from 50 to 150 mm
3.6m long vacuum chamber will arrive in October
Transport system is ready
7T.Lauer – EDM workshop Oak Ridge Oct.2012
UCN guides
Transmission was measured to be 97.6% per meter (similar to replica!)
8T.Lauer – EDM workshop Oak Ridge Oct.2012
UCN bend sections
(1-3) NiMo coated glass bends (300,450)(4) Stainless steel 450
selfmade bend sections:
92% transmission
9T.Lauer – EDM workshop Oak Ridge Oct.2012
UCN guides
Supermirror with m = 1.5 (360 neV): 15 double layers of NiMo and Ti
Bild
VF = 360 neV measured
10T.Lauer – EDM workshop Oak Ridge Oct.2012
What storage times can be expected?
We will hopefully investigate this next year at ILL
UCN Switch
Design for new switch will be similar (known technique)
11T.Lauer – EDM workshop Oak Ridge Oct.2012
Development of UCN polarizers
Bild große anlage
- supermirrors- polarizers- further neutron optics- ….
Sputtering facility for Planar substrates :
Substrat size : 700 x 300 mm²
12T.Lauer – EDM workshop Oak Ridge Oct.2012
3 magnetrons working in DC, RF or pulsed DC mode
Coating homogeneity
< 0.5%
Development of UCN polarizers
Polarisation with single iron layers on Al - foils96.0+/- 2.5% (magnetisation field 10mT!)
13T.Lauer – EDM workshop Oak Ridge Oct.2012
Development of UCN polarizers
14T.Lauer – EDM workshop Oak Ridge Oct.2012
Properties of the iron layer strongly depend on the production parameters
Magnetisation field 10mT
150nm thick iron layer
-> high transmission
A UCN superpolarizer
15T.Lauer – EDM workshop Oak Ridge Oct.2012
99.5 +/- 1.0%
10 double layers Fe/Si on Si-wafer or Al-foil
Spin Gymnastics
16T.Lauer – EDM workshop Oak Ridge Oct.2012
SC & SF solenoid
Cosine coil
Mu-metal shield
Cascade-U detector
Spin transport system is under preperation
Should be tested at beginning of 2013
Outlook
• Coating techniques and know-how exists
• UCN guides can be produced quite soon in new facility
• UCN polarizer foils can be producedDevelopment of a UCN detector for simultaneous spin detection in
collaboration with Heidelberg • Design of a working UCN switch exists and will be adapted
• UCN-shutter and -spin transport design is on the way
• We have to take care about the storage cells
17T.Lauer – EDM workshop Oak Ridge Oct.2012
Thank you for your attention
I. Altarev, V. Andreev, D. Beck, S. Chesnevskaya, T. Chupp, M. Daimer, P. Fierlinger, A. Frei, E. Gutsmiedl, A. Himpsl, F. Kuchler, T. Lauer, P. Link, T. Lins, M. Marino, J. McAndrew, S. Paul, G. Petzoldt, A. Pichlmaier, J. Rothe, S. Sharma, C. Schneider, R. Schönberger, S. Seidel, M. Steinmaßl, R. Stoepler, T. Stolz, S. Stuiber, M. Sturm, B. Taubenheim, R. Thiele, J. Weber, D. Wurm, T. Zechlau
18T.Lauer – EDM workshop Oak Ridge Oct.2012