Measuring ferromagnetic with Vibrating Sample Magnetometer D Richter

Measuring ferromagnetic with Vibrating Sample Magnetometer D. Richter With thanks to Luca, Amalia, and to Vincent Maire D. Richter, TE-MSC Technical Meeting, 3. 10. 2013

Synopsis • The VSM used by the MSC/SCD section • Measurement of the LHC ferromagnetic steel • What is the data good for? • And now ? ? D. Richter, TE-MSC Technical Meeting, 3. 10. 2013

Vibrating Sample Magnetometer • D. Richter, TE-MSC Technical Meeting, 3. 10. 2013

Theoretically OK • Sample: ‘Ø 4. 13± 0. 014 mm’ sphere of the LHC steel sample #944157 @ 4. 3 K (right picture). Stephan Russenschuck, TE-MSC Technical Meeting, 19. 9. 2013. D. Richter, TE-MSC Technical Meeting, 3. 10. 2013

Check linear • Sample: ‘Ø 4. 16 mm’ sphere of the LHC steel sample #944157 @ 4. 3 K (right picture). Kawabata S. , 1993 as cited in Stephan Russenschuck, TE-MSC Technical Meeting, 19. 9. 2013. D. Richter, TE-MSC Technical Meeting, 3. 10. 2013

Comparing two approaches • D. Richter, TE-MSC Technical Meeting, 3. 10. 2013

Case study • Kawabata S. , 1993 as cited in Stephan Russenschuck, TE-MSC Technical Meeting, 19. 9. 2013. D. Richter, TE-MSC Technical Meeting, 3. 10. 2013

Being picky – and perhaps wrong (? !) • Sample: sphere of the LHC steel sample #944157 @ 4. 3 K +0. 97 % cheated Ø 4. 13 mm D. Richter, TE-MSC Technical Meeting, 3. 10. 2013 as measured Ø 4. 09± 0. 014 mm.

Remanence & Coercivity • Sample: Ø 4. 0± 0. 1 mm sphere of the LHC steel sample #944157 @ 4. 3 K (right picture). Stephan Russenschuck, TE-MSC Technical Meeting, 19. 9. 2013. D. Richter, TE-MSC Technical Meeting, 3. 10. 2013

Minimum exploitable saple • demagnetizing factor, N (1) 1 0, 01 0, 0001 1 E-05 1 E-06 1 10 100 long-to-short dimension ratio, c/a (1) D. Richter, TE-MSC Technical Meeting, 3. 10. 2013 1000

Viable solution ? Zijstra H. : Experimental Methods in Magnetism, North-Holland, Amsterdam, 1967. • D. Richter, TE-MSC Technical Meeting, 3. 10. 2013

Conclusion • D. Richter, TE-MSC Technical Meeting, 3. 10. 2013