1. Insert - dipole common issues
M. Devaux
22/03/2011
EUCARD WP 7 HFM Collaboration meeting - Insert- dipole common issues- M. Devaux

2. Outline Mechanical structure Mechanical interface Thermal interface
Quench protection
Magnetic interface
Tests of insert inside Fresca II
22/03/2011
EUCARD WP 7 HFM Collaboration meeting - Insert- dipole common issues- M. Devaux

3. Mechanical structure Two independent structures:
- The insert will be maintained by the top:
Insert electric connections
Guiding plate of the insert: guiding and blocking the insert =
Need to open the cryostat to fix the insert
Screw M16
FRESCA II
FRESCA II
INSERT
Centering ring: guiding and centering all the systems to be tested in Fresca II (also the insert)
22/03/2011
EUCARD WP 7 HFM Collaboration meeting - Insert- dipole common issues- M. Devaux

4. Mechanical interface (1/2)
The insert is self-supporting
under 19 T:
Fx per quadrant = 3.4 MN/m
Fy per quadrant = MN/m
Influence on the forces of Fresca II:
Significant augmentation on Fy, however:
These values are inferior to the case of Fresca II is alone at 1,9K (15 T)
Forces on Fresca II
per quadrant
Alone
(under 13T)
With the insert (under 19T)
Fx(Fresca II) (MN/m)
7.7
7.3
Fy(Fresca II) (MN/m)
-3.81
-4.3
22/03/2011
EUCARD WP 7 HFM Collaboration meeting - Insert- dipole common issues- M. Devaux

5. Mechanical interface (2/2)
Force resultants on the conductors if the insert is not centered:
Forces resultants on the whole system {dipole + insert} is not null because the forces on the other magnetic circuits (yoke, poles and pads) have not been calculated
Force resultants created by the misalignment of the insert are negligent comparing to global forces
Center of the insert
X= 1 mm, Y= 0 mm
X= 0 mm, Y= 1 mm
ΣFx(insert) (N/m)
1400
ΣFy(insert) (N/m)
-2660
ΣFx(Fresca II) (N/m)
-4000
ΣFy(Fresca II) (N/m)
7160
22/03/2011
EUCARD WP 7 HFM Collaboration meeting - Insert- dipole common issues- M. Devaux

6. Thermal interface
The two magnets are operated at the same temperature.
They will cool down at the same time (using the inertia of FRESCA 2 for the insert) with the same way
The temperature of the insert cannot be under Tλ (otherwise the quench detection on the HTS is almost impossible)
HTS cooled by conduction
            
22/03/2011
EUCARD WP 7 HFM Collaboration meeting - Insert- dipole common issues- M. Devaux

7. Quench protection FRESCA 2 should not be damaged in any case
Different scenario risks (quench of the dipole, of the insert) will be considered and modeled – Calculations are going on
Calculations will be done to evaluate:
The energy transfer in different cases between the two magnets
The forces in the two magnets in case of quench on one of them    
22/03/2011
EUCARD WP 7 HFM Collaboration meeting - Insert- dipole common issues- M. Devaux

8. Magnetic interface
Magnetic calculations in 2D and 3D have been done with the two magnets.
Field vector maps with current or not in Fresca II :
In Fresca II, the magnetic flux due to the insert is opposite to the one due to Fresca II: This contributes to reduce the peak field of Fresca II
22/03/2011
EUCARD WP 7 HFM Collaboration meeting - Insert- dipole common issues- M. Devaux

9. Tests of the insert inside FRESCA II
The sequence of power setting of FRESCA II with the insert will be studied:
→ The load line of the dipole in function of the field B will be calculated with or without the insert
→ The value of the residual pre-stress on the Nb3Sn dipole will be plotted in function of the load line
Preliminary tests of the insert will be done outside Fresca II and are limited at je< 250 A/mm2
First tests of the insert inside FRESCA II will be done with a low field to study the resistive component of the insert.
22/03/2011
EUCARD WP 7 HFM Collaboration meeting - Insert- dipole common issues- M. Devaux

10. Conclusion
The insert will be designed in order to minimize the interaction with the dipole
Additional mechanical calculations are going on
Careful evaluation of the critical quench situation is underway
22/03/2011
EUCARD WP 7 HFM Collaboration meeting - Insert- dipole common issues- M. Devaux