| | 17 | |
| | 18 | == Notes: == |
| | 19 | |
| | 20 | **Present:** HTL, LC, KL, AK, JB |
| | 21 | |
| | 22 | 1. Notes and actions from [wiki:Research/Instrumentation/Meetings/2019/06-11 last meeting]: |
| | 23 | * **AK:** Establish minimum bending radius. |
| | 24 | * **Done.** Saint Gobain say "30--40 times the fibre diameter", so for us this would lead to the minimum bending radius being 7.5mm -- 10mm. This seems 'tight' to me. We should decide specification that we shall adopt. **Decision:** we adopt minimum bend radius 20mm. |
| | 25 | * **AK:** Place an order for clear fibre. |
| | 26 | * **Ongoing.** Have informal quote from Saint Gobain. AK has now asked for formal a quote so that a purchase order can be raised. Expect delivery in 6 weeks from placement of order. |
| | 27 | * **LC:** Produce drawings for quote. |
| | 28 | * **Done.** Posted in the [wiki:Research/Instrumentation/Documentation/Drawings drawing repository]. |
| | 29 | * **HT:** Simulate doublet layers potted in Araldite. |
| | 30 | * **Underway**: Geometry updated so that fibres are embedded in Araldite. Assumptions made re chemical composition of Araldite. |
| | 31 | * [raw-attachment:lightyield.pdf Slides.] Points noted: |
| | 32 | * Fibres enclosed in layer of Araldite. Composition of Araldit supplied by LC. Indication that there is little to no difference in energy deposition. Need to study in a little more detail. |
| | 33 | * **HT:** Try and estimate light yield from simulation. |
| | 34 | * **Underway**: Initial results presented in [raw-attachment:lightyield.pdf Slides.] Points noted: |
| | 35 | * First estimate of light-yield 10 -- 100 photons per proton. This means around 10^10^ -- 10^11^ parricles per spill. Max per fibre will be sent separately to JB by HT. |
| | 36 | * **HT:** Find MedAustron rep rate. |
| | 37 | * **Done.** See [raw-attachment:MedAustron-rates.txt note on time structure of beams at MedAustron]. |
| | 38 | * **HT:** Inject 90Sr electrons to estimate test-rig light yeild. |
| | 39 | * **Stands.** |
| | 40 | |
| | 41 | 2. Design update: LC \\ |
| | 42 | * [raw-attachment:190626-SmartPhantom.pdf Slides]. |
| | 43 | * Good progress: issue raised: how to exclude light from the waveguide. Need to develop a concept for the the light-guide support. |
| | 44 | * Later, when discussing the optical r/o, JB also asked how fibres would be finished. Need to finish the connector ends and the distal ends of the clear. A high polish might not be necessary. |
| | 45 | * **KL:** Agreed to take advice on how to finish the ends of the fibre. Noted that also need to design sock. Perhaps 3D print the cowling for the clear fibres at each end and join with, e.g. heat shrink. |
| | 46 | |
| | 47 | 3. Options for manufacture: LC, KL & discussion \\ |
| | 48 | * Imperial HEP and Departmental w/s can not deliver on timetable required. LC has contacted local industry to see if aluminium parts can be made. Expects this not to be a problem. |
| | 49 | * LC will consult R12 re machining PTFE for the lobes. May not require PTFE for this part as it will not be glued. |
| | 50 | * **LC**: Will re-evaluate based on discussion with R12. |
| | 51 | |
| | 52 | 4. Simulation update: HTL \\ |
| | 53 | * All progress discussed above. |
| | 54 | * Noted in response to question from JB that peak w/l for BCF20 fibre is in the green part of the optical spectrum. |
| | 55 | |
| | 56 | 5. Optical readout considerations: JB \\ |
| | 57 | * JB proposed to build a simple projection system. Adjustable doublet lenses with iris to control light. JB will check to see if a neutral-density filter will also be required. |
| | 58 | |
| | 59 | 6. Next steps |
| | 60 | * We **agreed** to move to production of prototype parts. |
| | 61 | * We **noted** that HT would return around 15Jul19 to get going on it assembly of prototype. |
| | 62 | * AK noted that HT would need a desk. And of course we'll need a place to do the assembly. |
| | 63 | |
| | 64 | 7. DONM |
| | 65 | * We **agreed** to meet fortnightly. KL will send diary invite. |
| | 66 | |
| | 67 | 8. AoB |
| | 68 | * KL noted that we are about to launch manufacture. S.Gruber (MUW) is aware of what we have planned but has not had sight of the design in its present form. We **agreed** to seek a meeting with her so that she can review what we have done. **KL** will broker the meeting. |
| | 69 | |
| | 70 | === Summary of actions: === |
| | 71 | * **AK:** Complete order for clear fibre. |
| | 72 | * **LC:** Re-issue drawings 'for the record' when ready. |
| | 73 | * **HT:** With KL, review simulation of doublet layers potted in Araldite. |
| | 74 | * **HT:** With KL, review estimate of light yield from simulation. |
| | 75 | * **HT:** Inject 90Sr electrons to estimate test-rig light yeild. |
| | 76 | * **KL:** Liaise to develop concept for polishing and light-exclusion from light guides. |
| | 77 | * **LC**: Re-evaluate use of PTFE based on discussion with R12. |
| | 78 | * **KL**: Work within Imperial to find assembly space. |
| | 79 | * **KL**: Seek meeting with S.Gruber to get her input into the design. |
| | 80 | |
| | 81 | ---- |
