Comments on Transmission Line, Remote Clamp, & TL Block Review

**February 26, 2002**

# Overview and Status

[Presenter: N. Grossman]{.underline}

1.  ([Reviewer: J. Kilmer]{.underline}) I\'m concerned about the level
    of drafting supplied to this task. It\'s not clear to me that the
    team can keep it\'s schedule without more drafting help. I would
    encourage the Numi management to try and get some more help from the
    PPD/MD for this.

This has been a constant problem with the entire NuMI Project -
insufficient drafting help -- resulting in much longer than anticipated
time to complete drafting. This, unfortunately, continues to be a
problem. The Project continues to work on improving this situation, or
at least stopping it from getting worse.

2.  ([Reviewer: F. Nezrick]{.underline}) I again state that I seriously
    question the need of the flex joint for Horn 1. Since the transverse
    position of Horn 1 most likely will not be scanned to verify beam
    centring, I do not see a justification for the flex joint. It adds
    extra cost, effort (time) and complexity.

The present joint allows some flexibility, albeit at a much smaller
level, due to this concern. It is no long a complicated design and
allows flexibility simply by having narrower strips of aluminum and
appropriate spacing of joints. (see
<http://www-numi.fnal.gov/numwork/tdh/tdh_index.html>, Section 4.3.5).

3.  ([Reviewer: F. Nezrick]{.underline}) In the note of Zhijing Tang of
    October, 2001 concerning the Finite Element Analysis of the flex
    joint, he notes the importance of keeping the slots at each bend to
    an equal length (also noted in Nancy\'s talk). Also if I understand
    the calculation correctly the slots lengths are always symmetric wrt
    the center of curvature for each bend of the transmission line, e.g.
    Figs 4, 10-14. This implies drawings on page 1, 4, 5 and 9 of the
    Drawing Package handout by Boettinger are incorrect.

The horn joint designs have been changed and no longer include slits.
(see <http://www-numi.fnal.gov/numwork/tdh/tdh_index.html>, Section
4.3.5)

4.  ([Reviewer: F. Nezrick]{.underline}) It is planned that the
    prototype flex joint and remote clamp will be pulse tested at MI8.
    It is essential that the prototype survive the testing. However we
    should require more. The testing plan lacks quantitative
    measurements (deflection at specific points, resonant frequencies,
    etc.) which might demonstrate agreement with expectations (ANSYS
    calculations, etc.) thus supporting an anticipated longevity.

Testing at MI8 has included some measurements of vibration & deflection.
This information has not yet been summarized and compared to ANSYS.

5.  ([Reviewer: F. Nezrick]{.underline}) The transmission lines in the
    target hall when pulsed will act like xylophone bars; they will
    undergo transverse and longitudinal vibrations. There is probably
    time and space to develop appropriate dampening methods after the TL
    system is installed. However, vibrations from the transmission lines
    and flex joints in and under the horn module should be better
    understood soon so space, e.g. for dampers, might be allowed in the
    module design. Hints might be obtained during the flex joint testing
    program at MI8.

The joints tested at MI8 are the ones that will go in the Target Hall.
The spacing of the clamps at MI8 is quite similar to the Target Hall
spacing. Measurements of deflection and vibration have been made at MI8
and as a result we are not concerned. These results need to be written
up.

6.  ([Reviewer: F. Nezrick]{.underline}) Nancy listed on Pg. 21 of her
    handout a Concern ::: \"Schedule is a bit tight.\" In the part of
    the installation schedule not shown on Pg. 20, but discussed at the
    review, it appeared that the amount of time allowed for testing
    (pulsing) the horn system in its running position was about one
    month. If no failures or major modifications are encountered, a
    month may be sufficient. My concern is that for various reasons this
    testing time might be reduced even more. It should be remembered
    this will be the first time the horn system will be operated in this
    configuration (supported from actual module with all appropriate
    motion controls and monitors installed, target installed, target
    hall transmission line attached, etc., etc.). Proper testing time
    must be rigidly scheduled, even if only 3rd shift.

We will do the best we can in this area.

7.  ([Reviewer: D. Pushka]{.underline}) Resources are just barely enough
    to pull off this work. Key areas where more help could be
    efficiently used is for drafting and will eventually include
    technicians for stripline assembly. Project management for NuMI
    needs to bring to the attention of the Beams Division management and
    relevent department heads the presently forseen technican shortage
    during the Miniboone installation and the NuMI work so that they can
    react in sufficient time to borrow additional help from other areas
    of the laboratory.

We have done and will continue to do the best we can in this area.

8.  ([Reviewer: D. Pushka]{.underline}) While the following comment is
    outside the presently budgeted scope of work and will require a
    large effort to pull off, the full production stripline and
    powersupply and horns one and two should be assembled in MI 8 after
    Miniboone clears out as a full scale assembly test. The full system
    will need to be assembled eventually. Current plan is to assemble it
    underground and this work is likely to be on the critical path (or
    near enought to it the any problems in the stripline assembly will
    put CD-4 in jeopardy). By starting the assembly earlier and in a
    service building, problems can be solved without affecting the
    critical path. This is more work because some effort will need to be
    duplicated, but if we are serious about reducing the length of the
    technical component installation, this is a wise and prudent
    addition.

We will do some level of assembly at MI-8 -- whatever seems to make
sense given the time and resources.