Feed horn array subsystem for QUBIC For Technological
Feed horn array sub-system for QUBIC For Technological Demonstrator (T. D. ) And For Final Instrument (F. I. ) QUBIC Collaboration Meeting, January 18/19, Milano 1
People involved (Uni. Mi) • Francesco Cavaliere (head of machine shop, mechanical supervision) • Federico Pezzotta (mechanical assembly, top and bottom flange production, metrological measurements, interface with manufacturer) • Daniele Viganò (mechanical support) • Paola Battaglia (metrological measurements, support to electromagnetic tests, electromagnetic simulations) • Elenia Manzan (MSc student, metrological measurements and analysis, electromagnetic simulations) • Aniello Mennella (scientific supervision, responsible for Uni. Mi) QUBIC Collaboration Meeting, January 18/19, Milano 2
8 x 8 module for T. D. QUBIC Collaboration Meeting, January 18/19, Milano 3
8 x 8 Horn Arrays: Status • Design: Completed • Manufacturing: Completed • Assembly: Almost completed – Modules A and B already assembled, but using different strategies. Final decision to be taken based on EM test results. • Test: In progress – UNIMI Metrology report on platelets available (16/02/2016, P. Battaglia et al. ) – Metrological tests also performed on assembled modules (flatness). Should be repeated upon final assembly. – EM tests: on-going in Milano-Bicocca QUBIC Collaboration Meeting, January 18/19, Milano 4
Horn mechanical development QUBIC Collaboration Meeting, January 18/19, Milano 5
Horn mechanical development QUBIC Collaboration Meeting, January 18/19, Milano 6
Horn mechanical development QUBIC Collaboration Meeting, January 18/19, Milano 7
Horn mechanical development QUBIC Collaboration Meeting, January 18/19, Milano 8
Horn mechanical development QUBIC Collaboration Meeting, January 18/19, Milano 9
Horn mechanical development QUBIC Collaboration Meeting, January 18/19, Milano 10
Horn mechanical development QUBIC Collaboration Meeting, January 18/19, Milano 11
Metrological inspections: Platelets Mechanical measurements performed at Uni. Mi with WERTH Scopecheck metrological machine Verify that platelets are produced within required tolerance Problem identified with 8 x 8 module due to etching time – will be corrected for final module QUBIC Collaboration Meeting, January 18/19, Milano 12
Metrological inspections: Platelets Module n. 1 QUBIC Collaboration Meeting, January 18/19, Milano 13
Metrological inspections: Platelets Module n. 2 QUBIC Collaboration Meeting, January 18/19, Milano 14
Effect on return loss - simulations Return loss at 150 GHz for three selected horns compared to nominal and requirement (module 1) QUBIC Collaboration Meeting, January 18/19, Milano 15
Effect on return loss - simulations Return loss at 150 GHz for three selected horns compared to nominal and requirement (module 2) QUBIC Collaboration Meeting, January 18/19, Milano 16
Effect on return loss – simulations and meas. Return loss at 150 GHz – comparison between simulations and measurements QUBIC Collaboration Meeting, January 18/19, Milano 17
Effect on beam pattern - simulations QUBIC Collaboration Meeting, January 18/19, Milano 18
Effect on beam pattern - simulations H plane 150 GHz QUBIC Collaboration Meeting, January 18/19, Milano 19
Effect on beam pattern - simulations QUBIC Collaboration Meeting, January 18/19, Milano 20
Effect on beam pattern - simulations QUBIC Collaboration Meeting, January 18/19, Milano 21
Tolerance problem on 8 x 8 • 8 x 8 prototype shows an out-of-spec problem on platelet diameters • This was not present on previous 2 x 2 prototypes • Discussions with manufacturer point to a possible problem in the chemical etching process (QUBIC platelets were etched typically at the end of the day, when the acid was somewhat exausted) • Problem not expected in final instrument horns: manufacturer will deliver platelets only after internal assessment of tolerance • Main effect on return loss, minor effect on beam pattern • Should not be an issue for technological demonstrator, will not be an issue for final instrument QUBIC Collaboration Meeting, January 18/19, Milano 22
Metrological inspections: Flatness Horn modules A and B have been assembled using different strategies: Module A: Torque on screws recursively adjusted to improve flatness of top surface. Module B: All screws fixed once at nominal torque value (0. 8 Nm) Flatness achieved: 0. 140 mm Flatness achieved: 0. 175 mm QUBIC Collaboration Meeting, January 18/19, Milano 23
400+400 module for F. I. QUBIC Collaboration Meeting, January 18/19, Milano 24
400+400 Horn Arrays: Status • Design: Almost completed – Platelets: design is already fixed – Top and bottom flanges: discussion on-going with Switches team to finalize the design (Horns-Switches interfaces, alignment options). Few candidates left, could be fixed by the end of this meeting. • Manufacturing: In progress – Platelets are currently being manufactured by chemical etching. Delivery expected by the end of February 2017 – CAD-CAM conversion and manufacturing of top and bottom flanges could start upon final design choice – M 3 Ergal screws have already been delivered. QUBIC Collaboration Meeting, January 18/19, Milano 25
400+400 Horn Arrays: Status • Assembly: To follow – Critical steps of the assembling procedure were assessed with 8 x 8 horn array – 20 x 20 will be larger, heavier, with many more screws: the task will be more difficult and will require more time Ø An optimized assembling strategy should be planned in advance based on current experience. Custom equipment may be required. • Test: To follow – Metrological inspection on 8 x 8 included all horns and all platelets – Preparing and performing all the measurements required more than one month Ø A more efficient strategy could be considered for the 20 x 20 (e. g. a subset of complete horns in relevant positions of the array). QUBIC Collaboration Meeting, January 18/19, Milano 26
400+400 Design: Platelets Each sheet can hold 4 platelets. Total amount of metal sheets: 352 QUBIC Collaboration Meeting, January 18/19, Milano 27
400+400 Manufacturing: Platelets First samples available (4 sheets): spot checks on horn holes dimensions revealed compliance with expected tolerances. QUBIC Collaboration Meeting, January 18/19, Milano 28
400+400 Design: Flanges Top flange (right): design is already fixed Bottom flange (left): design in almost completed. Interfaces and alignment choices with the switches block will drive the final solution (discussion is on-going on theese topics among Milano, Milano-Bicocca and APC). QUBIC Collaboration Meeting, January 18/19, Milano 29
Delivery dates: for Technological Demonstrator Project Number Resp. Item Task Start after task # 112 Milano-B Horns Tests at 150 + 220 Ghz of 8 x 8 Started 20/01/17 119 Milano / Milano-B B 2 B H+S assembly 03/04/17 07/04/17 112 / 118 QUBIC Collaboration Meeting, January 18/19, Milano Can start at Completion of fab / test and delivery at 30
Delivery dates: for Full Instrument Project Number Resp. Item Task 162 Milano 400+400 horns Fabrication and assembly 163 Milano-B 400+400 horns Test 167 Milano / Milano-B 400+400 H+S B 2 B Assembly Start after Can start at Completion task # of fab / test and delivery at Started 08/03/17 162 09/03/17 04/10/17 163 / 166 02/11/17 15/11/17 QUBIC Collaboration Meeting, January 18/19, Milano 31
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