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

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

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

Mechanical interface (1/2) The insert is self-supporting under 19 T: Fx per quadrant = 3.4 MN/m Fy per quadrant = -0.25 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

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

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

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

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

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

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