comments to the drawings

[Denisov <denisov@ihep.ru>]

Dear Colleagues,
These are comments to the corrected conceptual magnet and vacuum chamber 
drawings including strong-back support.

1.The drawings have been mailed to you and placed at 
http://levin.web.cern.ch/levin/.
2.Drawings of the quadrupole with support are not included: there were 
no questions about these items and the drawings were not changed.
3.The most of drawings are 2D but the final engineering drawings for 
production will be 3D drawings.
4.Materials and weights of the main parts are shown in the drawings.  
Magnetic characteristics of the yoke steel should be measured before 
machinning is started. Material costs are shown in the Cost estimate table.
5.Tolerances of the main magnet parts are shown in the drawings.
6.Lower poleshoes are bolted as requested.
7.Additional clamps along the side walls are used to minimize the magnet 
deformation and to reduce the inner bolts tension when the magnetic 
field is on. These are new elements and their deformations and tensions 
were calculated by finite element method and will be sent separately.
8. The number of vacuum brackets around the poleshoes are doubled.
9.The number and width of the coil support brackets are decreased 
considerably.
10. The O-rings of square cross section are used (see below).  But their 
shape is not important for the cost estimate.
11.The window between vacuum chamber and photon vacuum pipe is removed 
to minimize the background. The drawing which shows the connection 
between the chamber and the pipe is included.
12.Position of the photon vacuum pipe is not corrected because we don't 
know the exact beam direction. But this is not important for the cost 
estimate and can be done later.
13.It was checked that tensions of all bolts are at the acceptable level.
14.The gap between the poleshoes and the vacuum chamber without magnetic 
field is 200 microns. This gap garantee the stability of the chamber 
when the field is on.
15.Each picture in the assembly procedure has necessary comments as it 
was requested.
16.Magnetic field uniformity is shown in the fig. which will be sent 
separately of the drawings.
17. Proposed design of the vacuum sealing is standard for our designers 
and Workshop and seems more reliable. Use of the square O-ring is also 
standard for us although we have no objections to use any other type of 
O-ring.
18. There are no holes in the magnets for alignment tools and in the 
vacuum chamber for the probs to measure megnetic field: we have no 
necessary information. But we think that this is not very important at 
the moment: at least for the cost and schedule estimate.
19. Results of the magnet FEA and magnetic field uniformity calculations 
and corrected Table of cost estimate will be sent within few days.
20. Any comments, suggestions, questions, etc. are very welcome. But 
please take into account that this is not a final set of engineering 
drawings for production but just conceptual design necessary for the 
cost and schedule estimate.

Best regards.
Sergey.