1 / 14

Superconducting quadrupole magnets system in the interaction region of BEPCII

Superconducting quadrupole magnets system in the interaction region of BEPCII. CHEN, Fusan Feb. 6, 2007. Outline. The interaction region (IR) and the Superconducting (SC) Magnets. Introduction of the IR and the SC magnets. Winding of the SC magnets. The quench protection system (QPS).

nerys
Download Presentation

Superconducting quadrupole magnets system in the interaction region of BEPCII

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Superconducting quadrupole magnets system in the interaction region of BEPCII CHEN, Fusan Feb. 6, 2007

  2. Outline • The interaction region (IR) and the Superconducting (SC) Magnets. • Introduction of the IR and the SC magnets. • Winding of the SC magnets. • The quench protection system (QPS). • Quench detection system (QD). • Quench protection assembly (QPA) and the power supplies (PS) for the SC magnets. • The commissioning of the SC magnets. • Problems revealed in the commissioning.

  3. Interaction region of BEPCII

  4. The SC magnets for BEPCII • Coil structure • 3 anti-solenoid. • Main quadrupole. • Main dipole. • Vertical dipole corrector. • Skew quadrupole. • Powering configuration • Anti-solenoids are powered in series with one main PS. • Two trimming PS are used for current tuning.

  5. Winding of the magnets • Made by BNL/SMD • Direct wind technology. • Wind the cable directly ontothe support tube. • Serpentine style winding. • Double layers make completepoles.

  6. Quench detection system • Quench detection system (BNL) • DSP based digital quench detection system. • Easy to configure, diagnostic and query.

  7. Quench protection assembly • Quench protection actions fulfilled by three sub-systems. • Quench protection assembly interface chassis. • QPAIC sends out commands to other systems according to the quench protection logic resided in the PLC of QPAIC. • QPAIC can switch the operating mode for synchrotron radiation mode and collider mode. • Quench protection assembly and the power supply. • QPA is integrated into power supply. • QPA cuts off the powering circuit and switches the energy extraction resistor into the dump circuit. • Power supply control system. • Control system ramps down the power supplies without triggering the magnets quench at the case of common faults.

  8. Pictures of QPA Quench protection assembly interface chassis Back view of power supplies for SCB(HDC) Front panel of power supplies for SCB(HDC)

  9. Test of QPA • Act as predetermined logic • Fast response • Quench • 0.7ms • Fault • 5ms • Coherence • 7us

  10. Commissioning of SC • Maximum test current. • Anti-solenoid: 300A / 1300A • Main quadrupole: 205A / 580A • Corrector coils: ±40A / ±65A • Quench protection system is proved to be reliable. (React fast and correctly) • Problems are revealed with the valve box. • Coils are grounded with resistance 2~8000 ohms. • Gas cooled lead cannot be cooled down. • Main coils quench when currents go beyond 20% operating current. • Temperature imbalance between inlet and outlet leads

  11. Commissioning of SC • Voltage monitoring during commissioning. • The voltage drops across the gas cooled lead (Vc) and across the superconducting bus inside the transfer line (Vs) are monitored independently.

  12. Commissioning of SC/SCQ 162A 146A With the flow controller max, start the first ramping cycle Keeping the bypass valve open, start the second ramping cycle The SC bus quenches, but the normal region does not expand The SC bus does not quench at 162A 58A The SC bus cannot recover after opening the bypass valve Outlet Vt Inlet Vt Vt almost equals to Vc and Vs equals to zero for both inlet and outlet Outlet Vs Inlet Vs The SC bus recoveres after decreasing the current with the bypass valve opened

  13. Commissioning of SC/AS 297A 245A 197A The normal region does not expand at 297A The inlet SC bus quench causes the jump of voltage signals while current increases to ~260A 148A It is important to analyze why the outlet does not quench even the Vt higher The Vt difference between the inlet and outlet shows the imbalance of the helium flow 98A 49A Outlet Vt Inlet Vt 9A Inlet Vs Outlet Vs

  14. Conclusion • Most of the system work well. • The performance of the superconducting magnets is good during the vertical test completed in BNL. • The quench protection system can protect the magnets from any quench or faults. • The power supplies and the control system are workable although some small bugs still exist. • We do meet problems. • Most of the problems occur on the valve box. • Improvement is underway. • The valve box is redesigned and under machining.

More Related