Transcript Shielding of TOF I Decision to add a cage to the iron donut history Feb07, CERN Only proven solution available at the time Now local.

Shielding of TOF I
Decision to add a cage to the iron donut
history
Feb07, CERN
Only proven solution available at the time
Now local shields are proven OK, at least for TOF II
Confirmed at CM18 at RAL (TB)
Exec drawings available Ghislain+Wing
Jun07, CERN
Summer 07
Request to TB (PRR & construction approval) 5 Sep 07
No reply yet !
Expensive quote at Fermilab Alan
Early Oct 07
Discussed extensivey at CM19
PID, VP slides
Cheaper quote near Fermilab Alan
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
End Nov 07
Written opinions collected for this meeting 1) Bonesini
Dear all
in my understanding the baseline and EB endorsed option for TOF1 is the cage with brackets (the "expensive design"),
any other low-cost option (such as the screw-on plate option) is not endorsed at the same level of a local shielding.
The low cost option will imply probably not only the crane to pull up the second plate, but also the removal of the full
TOF1 detector including uncabling and putting it on a service stall for any operation on PMTs.
It is impossible (with the present frame design) to unscrew the PMTs of the first plane (no access from behind).
In addition I am puzzled by heavy gang operation nearby a delicate detector.
It seems as handling eggs nearby one ton of iron.
My position is yes for the cage as it is now or eventually local shielding, no for the screw up/down low cost option.
Cheers Maurizio
ps regarding the local shielding my cost estimate was around 5K with some moderate increase of work for my mechanics
workshop
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
Written opinions collected for this meeting 2) Gregoire I
Dear all,
here are my comments about the shielding cage for TOF1. I am referring particularly to the simplified cage proposed by Alan
and to the comments made by Maurizio.
The construction of the whole cage could be divided into three categories according to their cost (raw material and machining):
1.
the expensive parts (mainly labor-wise): the supporting brackets
2.
the reasonable cost items : a) the Virostek plate, b) the closing flange, c) the split ring, d) the hinge mechanism
3.
the inexpensive items: guide tubes, stoppers, plastic gliders, spacers, locking pins).
This division into three categories is partly based on my experience and on quotations I recently asked in Belgium (Louvain
workshop and commercial companies). From now on I shall neglect all items 3.
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
Written opinions collected for this meeting 2) Gregoire II
Comments:
A. Items 1 and 2A are absolutely mandatory for the operation of MICE and PID. Their fabrication should have
started since months ... and specific quotations would have been asked much earlier.
B. Items 2B,2C,2D and 3 could be replaced by a dedicated local shielding "à la TOF2" (... assuming an agreed design
of TOF2 ! which is not yet the case up to now!). But this requires new evaluations, a new mechanical design, new QA/Audit
procedure. It is not just a matter of scaling down the TOF2 case. In particular one should not cheat about the thickness of the
required local iron shielding.
C. Alan's proposal to make a simpler cage (no guide rails, cage opened by craning the closing flange ...). In the present
design, it should be remembered that TOF1 is attached to the closing flange and ,as such, would be lifted with the closing
flange. It would imply decabling the whole TOF1 which is not a really wise option. On the other hand and still with the
present design, it is not complicated to attach TOF1 to the Virostek plate (thus avoiding decabling!). But then the split ring
comes in the way, in the sense that it would be difficult to replace the PMTs located in the corners of the TOF1 setup, without
dismounting the whole TOF1.
Therefore, the practical way for implementing Alan's solution would be: - attach TOF1 on the Virostek plate, and - lift (as a
single piece) the closing flange and the split ring. One then gets easy access to all parts of TOFI without decabling. This meets
the wishes of Maurizio. - an advantage is that it completely avoids a specific support on the ground for TOF1 in an already
crowded area.
D. Budget-wise I do not think that Alan's solution makes lots of savings since the Virostek plate and supporting brackets
already represent a very sizable fraction of the total cost. According to the preliminary quotes I got from Louvain, the hinge
mechanism itself is not especially expensive compared to the rest. Vittorio already got a first overview of these quotes with
other details.
The closing flange should cost about 2 kEuros (including machining). I am rather confident that the total cost could be
decreased to about 20 kEuros (30 k$) at most. But it is certainly better to share the construction among different manufacturers:
commercial companies only for the two large items 1A and 2A, and lab/university workshops only for the more delicate and
smaller parts 2A to 2D. Further transportation savings could be done if manufactured in the US. The initial quotes of 60 k$ by
FNAL was ridiculous.
E. Concluding remarks
Considering the large amount of time lost (for various reasons!) since the completion of the whole design, and all the arguments
I wrote above, I think it wiser to go ahead with the present cage design. The local shielding option for TOF1 would imply
large delays (a couple of months) which are most probably not acceptable for MICE. Regards. Ghislain
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
Written opinions collected for this meeting 3) Lau
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
Written opinions collected for this meeting 4) Bross
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
On the basis of these opinions, debated in today’s PID ph meeting
and the new quotes and informations collected
the PID team recommends that
to be agreed tomorrow
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
The end
The old remaining slides are left below as one or two may be rescued to
illustrate better the motivations of the decision that we will take
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
Oggetto:
Data:
Da:
Rispondi-a:
Organizzazione:
A:
request to TB to approve construction of the TOF I Shielding Cage
5 Sep
Wed, 05 Sep 2007 23:23:51 +0200
Vittorio Palladino <[email protected]>
[email protected]
INFN Napoli
Alan Bross <[email protected]>, [email protected]
CC:
Wing Lau <[email protected]>, [email protected], Ghislain Gregoire <[email protected]>,
Maurizio Bonesini <[email protected]>, Steve Virostek <[email protected]>, [email protected], Peter Lau
<[email protected]>, Alain Blondel <[email protected]>, "Michael S. Zisman" <[email protected]>
Referenze:
<[email protected]>
Dear Ken (and Alan),
Ghislain completed his last checks and confirms Wing's opinion that the set of drawings at
http://www.physics.ox.ac.uk/design/MICE/Joe_TOFshielding_pdfdwgs/TOFshieldingdwgs_JT.htm
are indeed ready for production.
The PID group would like therefore to ask
1) the TB to give the green light for its construction.
2) Alan to inform us and the TB about the questions raised:
a) is the tentative plan to have the TOFI cage built in or around
Fermilab still viable?
b) would it be ready (for mounting and field mapping, including fringes
for TOFI) when the first solenoid arrives there from the Far West?
c) if so, are the drawings of appropriate quality for the workshop he
has in mind?
We hope to hear soon from both of you. Best regards
Vittorio
Reminder: were we to decide (soon) that a TOF II cage is also needed,
the same drawings can be used with the sole modification of the inner radii.
-------- Messaggio Originale -------Oggetto: decision process on TOF shielding cages
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
Oggetto:
[Mice-tb] Note on the TOF I shielding cage for the next TB: 14Sep07; 14:30 GMT ...
Data:
Da:
Rispondi-a:
Organizzazione:
A:
Thu, 13 Sep 2007 12:40:00 +0200
Vittorio Palladino <[email protected]>
13 Sep
[email protected]
INFN Napoli
[email protected]
CC:
[email protected], [email protected], Richard Apsimon <[email protected]>, Ghislain Gregoire <[email protected]>, Maurizio Bonesini
<[email protected]>, Lucien Cremaldi <[email protected]>
Referenze:
<001501c7f44b$d0fdd890$fbe18d80@cublt>
Dear Tech Boarders,
please find attached the note on the TOF I shielding cage that Ghislain
wrote in record time. Concerning point 3 of the agenda.
Concerning point 2 of the agenda, the TOF0-CKOV support stand, our
hope is to hear that a Production Readiness Review indeed is (or about to)
taking place.
I take the liberty to invite Maurizio, Lucien and Ghislain are invited
to the
meeting for these items, if there are no objections
Vittorio
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
due Jan 20 at RAL
general picture
TOF0,CKOV
TOFI, KL
at RAL
before Xmas
•
CKOV+TOF0 stand is Production Ready …. green light for Wing to build it
•
TOFI stand & shield undergoing Production Readiness Review
shielding plate + global PMT niche (cage)
PRR started ……
first Fermilab quote sobering (60K$)
… more quotes coming
…. the fewer changes the better
due Jan 15 at Fermilab
•
TOFII & beyond …….
final shield & layout being decided
cage, expensive, less practical
local PTM niches, attractive
as more practical and cheaper
•
SW = back end of eμC AL finish its design & find the money
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
TOFII at RAL
Jun 08
SW at RAL
uncertain
MICE PID PMT shielding needs
Large B fields
at PMTs
4 Tesla
An iron donut, the “Gregoire plate”
then to become known as Virostek plate,
drastically reduces the fields
will be built in each solenoid
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
Further PMT shielding needed
however
1) “Gregoire cage”
global shield
2) local heavy shields
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
With Cage II
Jan 08
B-mapped at FNAL Jan 15-Feb 15
including fringe fields
Apr 08
B-mapped at FNAL Apr 15-May 15
including fringe fields
Jul
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
Jul 08
No Cage II
Jan 08
B-mapped at FNAL Jan 15-Feb 15
including fringe fields
Apr 08
B-mapped at FNAL Apr 15-May 15
including fringe fields
Jul
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
Jul 08
Second 90’ of PID session on Sunday
GENERAL DOWNSTREAM LAYOUT
G. Gregoire
Shielding of TOF II & beyond: 3D calculation (15')
M. Bonesini
Decision process for shielding of TOF II & beyond (15')
Discussion on downstream layout (10')
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
Note to TB on Sep 14
Other file put on the web today
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding
We have two options
1)
Conclusion
stick to the baseline and “pay for it” ….or for a cheaper version of it …..
Vittorio,
At the PID meeting tomorrow can you bring up the following? The current design of the TOF1 mag cage is expensive partly because of the mechanism
that allows the TOF1 assembly to be slid out.
A much cheaper approach would be to have the TOF1 cage simply be a ring with a cover plate and the proper supports to hold the TOF1 assembly. But
there would be no mechanism to move it out sideways. To access the TOF1, the cover plate would have to come off. Ask Maurizio if he can do any
foreseeable maintenance in this configuration. Having to take off the cover plate is cumbersome and access may be an issue, but we should look into this
approach.
Still Trying.
Thanks,
Alan
cheaper may not imply downsizing ….. Mississipi would be great
Wing, Ghislain, Maurizio ready to focus on it
2)
evaluate if the alternative of local shields can seriously be set up in time
Ghislain can let us know if local shields are good enough within few (2-6) weeks
if he gives some priority to this on KL
Maurizio tells us that he can do in time (mid April) with 5 to 10 thousands extra Euros
to have the design adapted and the shields built & mounted on TOFI in magnetic contact with the
upstream Virostek plate
Our recommendation is not to do anything that delays 1)
MICEEB, 14 Dec 2007
V. Palladino TOF I shielding