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CERN/EF/ EHS-CC/78-57

9 June 1978

PROGRESS REPORT ON MAGNET M1

H. DESPORTES

Difficulties previously reported . on the conductor fabri-, . . cation and on the plastic rings are getting technically solved

but have resulted in considerable delays affecting the whole -

project. Delay on the conductor deliverr has now reached 5 months

and this time cannot be completely recovered during the magnet

fabrication. The overall schedule has been re-examined for possjblc

gains and a new version is attached to the present report. Delivery

of the first coi 1 is s che dule.d on 30 · March 1979 and of the second coi 1

on 30 June 1979. These dates do not leave any freeway for new

supplier delays or for incidents during the fabrication and tests.

CONDUCTOR

At the time of the previous CC meeting, the technical

problems with the conductor soldering appeared to be solved and the

long length production was just starting. Inspection of the first

long length showed again the poor quality experienced previously

and this length was rejected. Development work was resumed with the attendance of two engineers from SACLAY and finally enc.led up

with a fully satisfactpry process. Improvements were obtained by

proper cleaning and degreasing of the copper and of the composite,

by ru~ning the two components into a solder bath, by a better

control of the heating temperatures and by other small changes on -

the line.

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The first acceptable long length was run on May 26.

This length is just been delivered to SACLAY, so that the windin~ is now ready to start.

Two other lengths have been finished since then and are

being shipped. The other lengths should follow at ari adequate puce

provided all the remaining conductor components are ready in time .

SUPPORT RINGS

The design and development work of the plastic rings at

SNIAS have progressed somewhat. Stress analysis has been carriL

out to enable the mechanical structure to be completely defined.

The overall design of the rings, clamp plates and bolting is

completed. The glass fiber weaving pattern of the ring itself·

remains to be decided. This needed some preliminary tests on

unifilamentary composites which could not . be prepared until the

required S-glass was received. All the materials are now on hand

and first tests have been carried out : thermal contraction has

beeri measured both at RUTHERFORD and at GRENOBLE. Inter layer

shear stress measurements are under way at SNIAS. From the results,

the fiber glass structure will be decided and sample plates of tl1e

actual thickness will be made in order to carry out the con1plctc

test program decided upon.

Taking into account the time necessary £or this program

and for the fabrication of the rings, a revised delivery date has

been given by SNIAS : •first !ing at the 'end of November and second

two months later.

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DOME

After several discussions with CERN, the dome de s i pn

has been completed. This is now on tendering. It is the last

major part of the cryostat to be · ordered.

INSTRUMENTATION

Discussions have taken place with CERN in order to \

specify all the measuring probes which have to be installed within

the magnet and cryostat : temperatures, strain gauges, voltage

taps, etc~ A document will be issued shortly with th~ final speci-

fications as well as interfaces and wiring codes in accordance with EHS standards.

Equipments for the separate tests of the coils at SACLAY

have also been discussed. CERN proposes to bring to SACLAY the

power .supply and protection ~ircuit as a whole, the system hnving

been already tested together at CERN. For the reading and recor-

ding of the numerous measurements, CERN also has available a d11tn

handling system including a 200-channel scanner, a digital voltn1c-

ter, small computcir with read-outs, etc. SACLAY will have to

provide a terminal board t6 interconnect this system with tl1e

magnet instrumentation.

An engineer of CERN has been appointed for the instal-

lation of CERN parts of these equipments and to make the liaison

with SACLAY.

MISCEALLANEOUS WORKS

Practical work has been devoted to perfect the winJing

line and toolings.

Experimental work and tests of internancakc connections

ar still going on, as well as performance tests of the con-

ductor. A small model -coil has just been woun~ in order to test

the stability behaviour of the conductor in similar cooling nnd

field environment as in EHS. This test will be carried out soon.

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