1. Voltage tap layout and quench antenna options for the long QXF magnet
M. Marchevsky, LBNL
Apr 7, 2015

2. MQXF-L Vtap scheme proposal
6 voltage taps per layer
Monitoring splices, multi-turns, pole turns and the ramp
Only 2 taps (A4-A5) and (B4-B5) per each pole turn
Quench antenna is a primary signal source for the axial quench localization
Amount and locations of the QA sensors are to be determined

3. Quench antenna: earlier decisions
Meeting on Oct 30, 2014 notes:
• Different quench antenna options were discussed for SXQF and LQXF magnets. New quench antenna will be developed for LQXF magnets. The same quench antenna could be used in future for testing production magnets. SQXF will be used for testing the new quench antennas.
• Quench Antenna with 3 coil segments available at Fermilab will be used for testing short SQXF magnets.
• New Quench Antennas will be developed with two different options for installation: one in the warm finger (so called warm QA) and another one on the coil or in the cold area around the warm finger.
• As an option #1 HD-style “warm” quench antenna design will be optimized for LQXF coils and for a possible use in production magnets as well.
Action item on the QA:
Optimize HD-style QA design for LQXF coils.  Compare performance of “warm” and “cold”  QA (Maxim)

4. QA option for the cold space
Original HQ-style cold space antenna
Proposed MQXF-L cold space antenna
Extension of the HQ design to a longer length
Single layer coils are possible, as quench signals were shown to be quite large
Number od sensor stations and their separation is to be defined
turns of 0.2 mm diameter copper wire in a 9.5 mm wide groove (2-layer coils); dipole-bucked
Sensors are 120 mm apart
Tube wall thickness ~ 5 mm

5. QA option for the warm finger
Original HD-style warm bore antenna
Proposed MQXF-L warm bore antenna .
Axial sections (A)
End sections (B) x
Sectorial 2-layer PCB coils, dipole-bucked
Both coil types (axial and end-section) can be realized in this geometry by properly interconnecting the top and bottom layers of the PCB
Antenna sections can be monitored using built-in multiplexers to minimize number of signal wires
Modular design for easy transport and re-assembly
turns of 0.2 mm diameter copper wire
Sensors are 143 mm apart
Tube OD is 23.8 mm.