CEDAR Support Structure and existing PM Head Modifications.

Peter SutcliffeUniversity of Liverpool

1st September – University of Birmingham

Proposed CEDAR Concept Design

Existing PMT Head

Insulation (all yellow parts)

New Detector Support

Detector Frame

Cooling and Electronics

Light Guide

Mirror

N2 Environmental Casing

Existing 1251mm (to be shortened)

New Support Cylinder and Modified PMT Head Arrangement

• Support Cylinder Manufactured from Carbon Steel (Drawing NP53-01-13)– Flanges BS1560 GR 43 C or Similar.– Centre tube manufactured from standard

16” Diameter Schedule 20 seem welded pipe and skimmed to final dimensions.

• Existing PMT Support Head (drawing EA8086.596.0) to be Modified with the addition of 12 M12 ‘blind’ holes. (new drawing NP51-01-13)

• 1mm Neoprene gasket used as an N2 seal. (Drawing NP51-01-14)

• New support cylinder to be Located using 2 dowel screws at 90° and 270 °

Neoprene Gasket

New M12 Holes added to Existing PMT Head

New Support Cylinder

12-M12 Cap Head Screws

M12 Dowel Screws at this position

Modified PMT Head• 12 - M12 Holes to be

added at CERN.• 1st hole to be at TDC• No further processing is

required.

New Detector Support• Flanges Manufactured from

Carbon Steel BS1560 GR 43C (or similar)

• Cylinder 16” NB Schedule 20 carbon steel pipe, inner and outer diameters machined to clean up.

• All manufacture including welding to be done at Liverpool.

• No coded welders here, so we will have to go to a sub contractor for X Ray NDT or possibly use dye penetrant testing methods.

• Surface to be chemi blacked for corrosion resistance.

FE Analysis

• FE Mesh and physical constraints– Finite Element Software used: ANSYS– Material: Carbon Steel– E = 196 GN/m2

– Density = 7854 Kg/m3

– Loads Applied:200Kg in the form of a solid cylinder representing the supported detector.

Flanges

Cylinder

Load applied

Flange constraints

FE Results

This figure shows the maximum deflection in Y of 0.055mm, due to gravity with a 100Kg Load representing the detector.

This figure shows the maximum stress of 1.2MPa which is very low. Maximum Yield stress for carbon steel is around 220MPa

Details of Concept

Installation• Head assembly will be in

place at time of beam line installation.

• Frame and Environmental casing is split. Each half will be pre-assembled and tested.

• Cooling will be fixed in place and electronics, pmt’s and light guide can be replaced by sliding a complete assembly out and repairing and replacing faulty components.

• Tapes and cooling tubes to be fed out at the bottom, through the environmental casing.

Current Concept...comments?