1. D. Cheng Sept 23, 2013 Instrumentation Trace Material Selection

2. Outline 9/23/13D. Cheng2 Current LARP trace production Issues experienced Other materials available

3. LARP Coil Instrumentation 9/23/13D. Cheng3 StainlessLaminate Adhesive* Polyimide (Apical AV) Additional Kapton** TQ/LQ304 / 25 µm15 µm25 µm- HQ Coils 1-10304 / 25 µm15 µm25 µm- HQ Coils 11-14304 / 25 µm15 µm25 µm HQ Coils 15-21304 / 25 µm15 µm25 µm50 µm HQ Coils 22-26304 / 25 µm15 µm25 µm LHQ304 / 25 µm15 µm25 µm50 µm *Modified cross-linked epoxy system, AS 1084 ** Joined by single strip of 3M VHB F-9460PC

4. Instrumentation Trace Fabrication Process 9/23/13D. Cheng4 Design and print artwork (negative mask) Cut trace laminated material to length Cover conductive laminate with resist Expose resist under negative mask with UV light Wash the uncured resist from laminate Etch laminated material with cured resist pattern – Conductive layer covered by resist remains Remaining resist washed off by stripping agent

5. Instrumentation Trace Impreg. Preparations 9/23/13D. Cheng5 Electrical QA Bond additional layer of Kapton – 25 µm (earlier iterations) – 50 µm (current) Perforate polyimide layers Install during coil impregnation

6. Experiences with Traces During Coil Fabrication 9/23/13D. Cheng6 Pinholes have caused electrical failures – A few were caused by materials – Some were caused by the handling Additional layers (25 µm or 50 µm) of Kapton were added for protection – Some laminated traces did not fully impregnate

7. Pinholes 9/23/13D. Cheng7 Material flaw (inclusion) that caused a hipot failure during electrical QA

8. Impregnation Between Polyimide Layers 9/23/13D. Cheng8 Coil 14 OL, end of ramp area, post-impregnation, sectioned Coil 14 OL, end of ramp area, trace peeled off Lack of fill between layersCoil itself shows good impregnation

9. Potential Heater/Instrumentation Materials 9/23/13D. Cheng9 Current trace designs specify 50 µm thick polyimide backing, therefore the following options exist: ConductorLaminate Adhesive* PolyimidePolyimide Thickness GTS, Apical AV316 SS / 25 µm15 µmApical AV**25 µm GTS, Kapton MT316 SS / 25 µm15 µmKapton MT25 µm Dupont Pyralux AP (25) Cu / 25 µm-Pyralux AP (Polyimide) 25 µm GTS, Apical AV316 SS / 25 µm15 µmApical AV**50 µm GTS, Kapton MT316 SS / 25 µm15 µmKapton MT50 µm DuPont Pyralux AP (50) Cu / 25 µm-Pyralux AP (Polyimide) 50 µm *Modified cross-linked epoxy system, AS 1084 **Apical AV is similar in thermal conductivity as Kapton HN (0.19 W/mK)

10. Materials Options Summary 9/23/1310D. Cheng ProsConsNotes 25 µm thick polyimide trace materials Additional layer of polyimide protects against material flaws Entire laminate may not impregnate well; Unknown epoxy layer thickness after impregnation Requires additional 25 µm layer of polyimide 50 µm thick polyimide trace materials Improved impregnation due to single layer of material Does not inherently provide protection from material flaws Does not require additional layer of polyimide Copper trace materials (Pyralux AP) One less layer between heater and conductor; polyimide is 0.26 W/mK @ ~RT Unknown performance (SS only has been used in LARP) No adhesive layer between copper and polyimide (directly bonded) Kapton MT0.37 W/mK (3x Kapton HN equiv. at ~RT) Unknown performance (has not been tested) Same laminate bonding process as SS materials

11. Additional Slides 9/23/1311D. Cheng