Injector Solenoids Upgrade

Injector Solenoids - Review

Introduction

A variety of solenoid magnets have been in use at the CEBAF injector for over 20 years. A total of 11 individual solenoids are installed, spanning 7 different types (FH,FB,FG,FQ,FA,FD,FL). In order to preserve the beam polarization four of the type two internal counter-wound coils (FQ,FA,FD,FL) while others have a single internal coil (FH,FB,FG). A summary of the 11 coils is listed below and can found on the injector songsheet media:190605_injectorsongsheet.pdf.

• MFH2I01 - beam line solenoid, single wound
• MFB1I02 - beam line solenoid, single wound
• MFG1I04A - beam line solenoid, single wound
• MFG1I04B - beam line solenoid, single wound
• MFQ0I01 - beam line solenoid, counter wound
• MFA0I03 - beam line solenoid, counter wound
• MFD0I04 - two chopper solenoids in series, each counter wound
• MFA0I05 - beam line solenoid, counter wound
• MFA0I06 - beam line solenoid, counter wound
• MFL0I07 - beam line solenoid, counter wound

While the magnets work reliably, there is an initiative to replace these solenoids with new magnets so the following is achieved:

1. fewest types possible, to improve standardization and spares inventory
2. greater radial field uniformity, to minimize variation of beam optics with beam position
3. minimum field roll-off in the beam direction
4. design accommodating operation at higher beam energy, i.e. function at higher power supply current
5. larger inner diameter to accommodate 2-3/4" flanges
6. bakable to >200C for extended periods for vacuum condition
7. capability to be interchangeably wired for single wound or counter wound configuration

With these considerations in mind Jay Benesh has modeled an upgrade solenoid magnet and worked with Danny Machie to develop a mechanical design, in three variations, that have been reviewed by the injector and source groups. The purpose of your review is to inspect the proposed specifications and drawings tand provide feedback or questions that should be incorporated prior to starting the vendor RFQ process.

Materials to be supplied for RFQ

• Specification to vendor - media:magnet_spec.pdf or media:magnet_spec.odt
• Coil drawing - media:coil8may19.pdf
• Low Momentum Solenoid (replaces FH, FB, FA, FL beam line magnets) - media:lowmomentumbeamlinesketch5.pdf
• Low Momentum Solenoid (replaces FD chopper magnets) - media:lowmomentumchoppersketch2.pdf
• Low Momentum Solenoid (proposed new solenoid for MeV beam energies) - media:highmomentumbeamlinesketch4.pdf

Vendor List

Everson-Tesla Inc., Doug Hartman (dhartman@eversontesla.com)

Supplemental Material

• Optics assessment of keV solenoids of different ID media:design_comp.pdf