Meeting at Chooz PMTs Mechanical support on the Buffer. Updates. Enrique Calvo Alamillo

Meeting at Chooz Index PMTs support structure on the buffer. Update. Cables routing on the buffer wall. Assembly process of the PMTs support. Tooling of the gamma-catcher and target at Ciemat workshop. Next steps:

Meeting at Chooz PMTs support estructure on the buffer. Update. Following last Madrid meeting request, we modified the PMT support to fit to the proposed modification. We have: -Reduce 5 cm the height of the magnetic shielding. -Put only One magnetic shielding layer. -Fix the PMT on the equator with 2 ring. -Reduce the material for the support.

Meeting at Chooz This fig. shows the result with the main parameters.

Meeting at Chooz 3D model of the PMTs support with the concentrator. This new design have 1.5 kg of acrylic material instead of 2.2 kg.

Meeting at Chooz PMTs Positioning: Main parameters

This show 1/6 sector of the PMTs distribution in the buffer. PMTs parameters on the Lid. -First ring: R=585 mm. Angle=30º -Second ring: R=980 mm. Angle= 17º/43º -Thirst ring: R=1425 mm. Angle= 13º/30º/47º Fourth ring: R= 1900 mm. Angle= 10.5º/23.5º/36.5º/49.5º

Meeting at Chooz Cables routing on the buffer wall. This point correspond to the PMT-phone meeting of the

Meeting at Chooz Labeling of the different cables routing, used to obtain the different cable length inside of the buffer. Circular Sector1 Position 1Circular Sector2 Position 1 Circular Sector3 Position 1 Circular Sector4 Position 1 Circular Sector4 Position 2 Circular Sector4 Position 3 Circular Sector2 Position 2 Circular Sector3 Position 2 Circular Sector3 Position 3 Circular Sector4 Position 4

Meeting at Chooz On each routing profile exit 11 cables. *9 for each column of the circumferential PMTs. *2 of the base PMTs

Meeting at Chooz Detail of the 9 different routing on the cylindrical side of the buffer

Meeting at Chooz Detail of the cables routing on the base side of the buffer (1).

Meeting at Chooz Detail of the cables routing on the base side of the buffer (2).

Meeting at Chooz Detail of the cables routing on the base side of the buffer (3).

Meeting at Chooz The different cables will be attached to the metallic structure by CLIPS. You can see on the photograph one of these clips. The material of this clip is Nylon 6.6. The table show the different length obtained between the PMT to the end of the profile on the cylindrical side of the buffer.

Meeting at Chooz Assembly process of the PMTs support. This was described on the TDR. We will follow four different assembly scenarios. Each scenario describes the different steps to complete the assembly. But it is necessary update this to the last design. How example I will show the first, the rest are in the TDR.

Meeting at Chooz A.- Sub-Assembly of the magnetic shield plus concentrator -On a table we put a “mounting piece” (red piece) to permit the positioning of the different elements and to optimize the operation time. On this piece we put the four column in the holes machined to permit the positioning. -Put on the top the bottom ring of the sub-structure. Fix the screws definitively. And rotate 180º the assembly.

Meeting at Chooz - Insert the magnetic shield in the slot of the bottom ring. -Install the top ring and put the screws definitively.

Meeting at Chooz -And finally mount the concentrator on the top ring and fix the screws definitively.

Meeting at Chooz Tooling of the gamma-catcher and target at Ciemat workshop. At Madrid are under fabrication 3 different tools kind following the drawing supplied by Patrick Perrin and J.François Millot: Three tools units for the target. Two rotation tools units. One tool unit for the gamma catcher. Will be ready for the next June-July. Ready for August- September. Ready for July.

Meeting at Chooz Next Step: Detailed step by step the Cleaning Procedure for the PMTs mechanical support pieces, following the TDR. Installation process of the PMTs on the buffer. Define the tooling necessary for those Jobs. Define the Space Requirements to do the previous task. Pressure test at Ciemat during June-July. Still pending: Study the feasibility of implementing the fixation points together with the buffer construction people, to fix the structural support on the buffer. Optimize the fabrication process of the different mechanic pieces. Design of the mechanical devices to permit machine/weld the different fixation points on the buffer with the acceptable tolerance.

This is the first PMT with base received at Madrid. It is mounted in the acrylic support showed last march.