+---------+---------+---+-----+----------------+-----------------------+
| In      |         |   |     |                |                       |
| terface |         |   |     |                |                       |
| Specif  |         |   |     |                |                       |
| ication |         |   |     |                |                       |
+---------+---------+---+-----+----------------+-----------------------+
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| c       |         |   |     |                |                       |
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| -- D3   |         |   |     |                |                       |
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|         |         |   |     |                |                       |
| REVISED |         |   |     |                |                       |
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+---------+---------+---+-----+----------------+-----------------------+
| A       |         |   |     |                |                       |
| bstract |         |   |     |                |                       |
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| \[Text  |         |   |     |                |                       |
| of the  |         |   |     |                |                       |
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+---------+---------+---+-----+----------------+-----------------------+
| P       |         |   | Re  |                | Approved by :         |
| repared |         |   | vie |                |                       |
| by :    |         |   | wed |                | \[Name\]              |
|         |         |   | by  |                |                       |
| S.      |         |   | :   |                | \                     |
| Plate   |         |   |     |                | [division/institute\] |
|         |         |   | E.  |                |                       |
| BNL     |         |   | Wil |                | \[electronic.mail\]   |
|         |         |   | len |                |                       |
| <       |         |   |     |                |                       |
| Plate@b |         |   | BNL |                |                       |
| nl.gov> |         |   |     |                |                       |
|         |         |   | Wi  |                |                       |
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|         |         |   | gov |                |                       |
+---------+---------+---+-----+----------------+-----------------------+
|         |         |   |     |                |                       |
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| History |         |   |     |                |                       |
| of      |         |   |     |                |                       |
| Changes |         |   |     |                |                       |
+---------+---------+---+-----+----------------+-----------------------+
| Rev.    | Date    | P |     | Description of |                       |
| No.     |         | a |     | Changes        |                       |
|         |         | g |     |                |                       |
|         |         | e |     |                |                       |
|         |         | s |     |                |                       |
+---------+---------+---+-----+----------------+-----------------------+
| 0.1     |         |   |     | First Draft    |                       |
+---------+---------+---+-----+----------------+-----------------------+

Table of Contents (not compulsory, can be removed)

1\. General [Error! Bookmark not defined.](#__RefHeading___Toc462636186)

2\. D3 Interfaces [7](#lbrs-interfaces---lead-end)

3\. D3b Interfaces [Error! Bookmark not
defined.](#__RefHeading___Toc462636188)

# introduction

Each superconducting D3 dipole cryo-assembly (LBRS) will be a dual
aperture assembly comprised of two single aperture cold masses in a
common vacuum tank. Each cold mass (MBRS) contains a RHIC-type coil
assembly \[1,2,3\]. The D3 magnets, along with D4 magnets, are used at
IR4 to increase the separation of the beams of the LHC from the nominal
spacing of 194 mm to 420 mm so that individual RF cavities can be
installed for each beam. The beams are then returned to the nominal 194
mm spacing \[1\].

![](media/image1.wmf)One D3 magnet is located on each side of IP 4, plus
one spare is to be built. One side of the region is shown in Figure 1.
D3 magnets operate at 4.5K in two-phase helium.

***Figure 1 Layout of D3 and D4 in the left side of Intersection Region
4. D3 and D4 change the beam separation from 194 mm to 420 mm.***

> The configurations of the two D3 cryo-assemblies are identical. The
> same magnet assembly is turned 180° for use on the opposite side of
> the IP. One spare D3 is built to replace either of the two installed
> units.

# general specifications

The LBRS cryo-assemblies use 8 cm aperture RHIC cold masses (but without
sagitta), which employ the stressed yoke design as a collar rather than
separate collared coils. There are two such cold masses in an LBRS
cryo-assembly. The cryostat for D3 is 914mm (36 in) in diameter, the
same as the LHC arc dipole. Table 1 contains a summary of the LBRS
parameters.

***Table Specifications of the LBRB Cryo-assemblies***

+--------------------------------------------------+-------------------+
| Item                                             | Value             |
+--------------------------------------------------+-------------------+
| Quantity + (Spares)                              | 2 + (1)           |
+--------------------------------------------------+-------------------+
| Operating Temperature                            | 4.5 K             |
+--------------------------------------------------+-------------------+
| Beam Tube OD / ID                                | 73 / 69 mm        |
+--------------------------------------------------+-------------------+
| Beam Dynamic Heat Load                           | Screen            |
+--------------------------------------------------+-------------------+
| Coil Prestressed                                 | Yoke              |
+--------------------------------------------------+-------------------+
| Cold Mass Design                                 | 1 in 1            |
+--------------------------------------------------+-------------------+
| Bore Spacing (cold)                              | 414 mm            |
+--------------------------------------------------+-------------------+
| Yoke Diameter                                    | 267 mm (10.5 in)  |
+--------------------------------------------------+-------------------+
| Shell Thickness                                  | 4.8 mm (0.190)    |
|                                                  | in)               |
+--------------------------------------------------+-------------------+
| End Plate Thickness                              | 32 mm (1.25 in)   |
+--------------------------------------------------+-------------------+
| Length (end plate -- endplate)                   | 9.72 m (382.7)    |
|                                                  | in)               |
+--------------------------------------------------+-------------------+
| Length (end volume -- end volume)                | 10.13 m (398.82)  |
|                                                  |                   |
| (not centered WRT cryostat;100mm shorter at NLE) |                   |
+--------------------------------------------------+-------------------+
| Cold Masses per Cryostat                         | 2                 |
+--------------------------------------------------+-------------------+
| Cryostat Length                                  | 9.646 m (379.75)  |
|                                                  | in)               |
+--------------------------------------------------+-------------------+
| Cryostat Diameter                                | 914 mm (36 in)    |
+--------------------------------------------------+-------------------+

# general layout

## Cryo-assembly cross section

![](media/image2.wmf){width="5.895138888888889in" height="7.0in"}The
LBRS (D3) cryo-assembly cross section at a support post location, as
viewed from the lead end, is shown in Figure 2.

Figure 2 [Cross Section]{.mark} of the D3 (LBRS) Cryo-assembly at a
support post location, viewed from the lead end of the magnet.

## local coordinate system

Figure 3 shows the LBRS local coordinate system which is similar to the
LHC standard for local coordinate systems \[5\] except that the origin
is always located at the lead end of D3. The XZ plane is coincident with
the flat face of the MBRS lead end volume (Y=0) and is centered between
the two cold bore tubes. Positive X always points toward the LHC ring
center.

The coordinate system is defined in the same way for both warm and cold
conditions, i.e. it is fixed at the lead end between the cold masses.
This results in a displacement of the coordinate system due to thermal
contraction of the cold masses. The cold origin is displaced 1.1mm in
the negative Z-direction (down) with respect to the warm position. It is
displaced 16 mm in the positive Y-direction for a magnet on the left
side of the IP, and 16 mm in the negative Y-direction for a magnet on
the right side.

![](media/image3.wmf){width="5.875in" height="4.038194444444445in"}

***Figure 3 [Local coordinate system for LBRS]{.mark} for the left side
of the IP. The flat surface shown at the lead end volume is coincident
with the cold mass virtual plane referenced in specification
LHC-LI-ES-0001. \[6\]***

## piping

![](media/image4.wmf){width="4.25in" height="1.8159722222222223in"}
Figure 4 shows transverse and longitudinal views of the lead end of the
magnets and cryostat. The letters used to label the pipes and tubes that
BNL has designed into the system correspond (where applicable) to the
header pipes, labelled in upper case letters on the CERN cryogenic flow
diagrams, to which the magnet piping eventually connects. These views
also show the tubing stubs protruding from the end volumes of the cold
masses. Tubing stubs are needed to admit liquid helium, vent gaseous
helium, and convey buses through liquid helium to the source of
electrical power. The details of the cooling system are described in
\[7\].

***Figure 4 Cryogenic connections at the lead end volume***

Coming out of the end volumes of each cold mass there are four tubing
stubs, three at the lead end (m/c, CL/LD, and i), and one at the
non-lead end (LD/CL). All stubs emanate from the flat faces of the end
volumes.

Stubs labelled CL are used to admit liquid helium into the cold mass
either in cooldown mode or steady state mode. Stubs labelled LD are used
as vents to return helium gas, collected in the top of the end volume,
to the cryogenic system, via the QQS. The LD lines from each cold mass
are connected together via a flex hose and suitable tube fittings,
consistent with the cryogenic schematic. This allows for a common LD
line in the QQS, reducing plumbing congestion. The m/c stubs at the lead
end provide tubes to bring electrical power from the DFBM to each of the
D3 cold masses and to the undulator, as well as for the liquid helium to
provide bus cooling up to the plug.

The i stub is provided for the instrumentation leads to exit the end
volume. An instrumentation feedthrough system (IFS) is attached by BNL
to the i stub; CERN does not interface to the i stub, but does interface
directly with the end of the IFS. The IFS is described in more detail in
section 4.2.

Shown within the cryostat are the shield supply and return pipes
labelled e~1~ and e~2~. Pipe e~1~ is the shield pipe which is an
integral part of the CERN-supplied heat shield extrusion and is
therefore thermally connected to the shield. Pipe e~2~ is a stainless
steel line inserted within the shield and intentionally thermally
isolated somewhat from it to prevent cooling instability. Cooling gas
can enter either e~1~ or e~2~ first, and return through the other,
without affecting shield function.

# LBRS Interfaces - LEAD END 

Two D3 magnet assemblies plus one spare will be built. The two D3
magnets are located in IP4L and IP4R. As installed in the LHC ring, the
configurations of the two assemblies are the same. BNL will produce
three identical units which operate at 4.5K.

The lead end of each cold mass (two per D3 assembly) always faces away
from the IP and connects to the DFBM and the QQS. Magnet D3 is fed
cryogens via the QQS and bus power via the DFBM (both are built and
attached by CERN). In addition, a CERN-built and supplied undulator
magnet is attached after shipment to the non-lead end of D3. A separate
through-bus, integral to one of the D3 cold masses, is fed from the QQS
and in turn feeds the undulator.

## tube coordinates

The sizes of the various tubing stubs for the D3 magnet and their warm
coordinate positions on the left and right sides of the IP are shown in
Tables 2 & 3. Welding and cutting clearances have been taken into
account in positioning these tubes so that there exist clearance
envelopes of 50 mm radially around each pipe.

![](media/image5.wmf){width="0.875in"
height="0.5569444444444445in"}***Table Warm coordinate positions for the
D3 lead end on the left side of the IP. Positions shown are for both
cold masses. Most pipes are in standard US sizes.***

+-----+-------------------+----------+-----+---+-----+---+-----+---+
|     |                   | ***OD x  | *   |   |     |   |     |   |
|     |                   | Wall***  | **W |   |     |   |     |   |
|     |                   |          | arm |   |     |   |     |   |
|     |                   |          | Co  |   |     |   |     |   |
|     |                   |          | ord |   |     |   |     |   |
|     |                   |          | ina |   |     |   |     |   |
|     |                   |          | tes |   |     |   |     |   |
|     |                   |          | *** |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| *   | ***Description*** | **       | *   |   | *   |   | *   |   |
| **N |                   | *Tube*** | **X |   | **Z |   | **Y |   |
| ame |                   |          | (   |   | (   |   | (   |   |
| *** |                   | **       | mm) |   | mm) |   | mm) |   |
|     |                   | *(mm)*** | *** |   | *** |   | *** |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| V1  | Cold bore tube,   | 73 x 1.9 | -20 | ± | 0.0 | ± | -15 | ± |
|     | left aperture     |          | 7.6 | 1 |     | 1 | 0.0 | 2 |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| V2  | Cold bore tube,   | 73 x 1.9 | 20  | ± | 0.0 | ± | -15 | ± |
|     | right aperture    |          | 7.6 | 1 |     | 1 | 0.0 | 2 |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| CL  | Helium sup/ret on | 38.1 x   | ±20 | ± | 13  | ± | -7  | ± |
| /LD | end vol (two)     | 1.65     | 7.6 | 2 | 1.1 | 2 | 5.0 | 2 |
| s   |                   |          |     |   |     |   |     |   |
| tub |                   |          |     |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| CL  | Helium sup/ret    | 38.1 x   | ±3  | ± | 21  | ± | -7  | ± |
| /LD | transfer lines    | 1.65     | 2.4 | 2 | 6.6 | 2 | 5.0 | 2 |
| x   | (two)             |          |     |   | ^c^ |   |     |   |
| fer |                   |          |     |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| m/c | Bus/helium tubes  | 63.5 x   | ±20 | ± | -13 | ± | -7  | ± |
|     | (two)             | 1.65     | 7.6 | 1 | 4.2 | 1 | 5.0 | 2 |
|     |                   |          |     |   |     |   |     |   |
|     |                   | 89.4 x   |     |   |     |   |     |   |
|     |                   | 1.65^a^  |     |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| e   | Heat shield       | 17.2 x   | -27 | ± | -29 | ± | 5   | ± |
| ~1~ | sup/ret           | 1.0      | 0.0 | 2 | 0.0 | 2 | 6.0 | 2 |
|     | (connected)       |          |     |   |     |   |     |   |
|     |                   | 87.0 x   |     |   |     |   |     |   |
|     |                   | 3.5^b^   |     |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| e   | Heat shield       | 17.2 x   | 27  | ± | -32 | ± | 5   | ± |
| ~2~ | ret/sup           | 1.0      | 0.0 | 2 | 0.5 | 2 | 6.0 | 2 |
|     | (isolated)        |          |     |   |     |   |     |   |
|     |                   | 19.0 x   |     |   |     |   |     |   |
|     |                   | 1.65^b^  |     |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| W   | Cryostat          | 1055 x   | 0.0 | ± | -8  | ± | 32  | ± |
|     | (rotatable        | 61.5     |     | 3 | 0.0 | 3 | 2.0 | 3 |
|     | flange)           |          |     |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| W'  | Cryostat (flange  | 1008 x   | 0.0 | ± | -8  | ± | 29  | ± |
|     | mount)            | 59.0     |     | 3 | 0.0 | 3 | 2.0 | 3 |
+-----+-------------------+----------+-----+---+-----+---+-----+---+

Note a: Dimensions of flanges welded to tubes. The flange faces, when
they are present, are located at the interface.

Note b: Dimensions of tube behind interface. A transition section is
used to reach the metric interface dimension of 17.2 x 1.0.

Note c: transfer lines are tilted to facilitate gas flow; lead end
always higher.

![](media/image6.wmf)***Table Warm coordinate positions for the D3 lead
end on the right side of the IP. Positions shown are for both cold
masses. Most pipes are in standard US sizes.***

+-----+-------------------+----------+-----+---+-----+---+-----+---+
|     |                   | ***OD x  | *   |   |     |   |     |   |
|     |                   | Wall***  | **W |   |     |   |     |   |
|     |                   |          | arm |   |     |   |     |   |
|     |                   |          | Co  |   |     |   |     |   |
|     |                   |          | ord |   |     |   |     |   |
|     |                   |          | ina |   |     |   |     |   |
|     |                   |          | tes |   |     |   |     |   |
|     |                   |          | *** |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| *   | ***Description*** | **       | *   |   | *   |   | *   |   |
| **N |                   | *Tube*** | **X |   | **Z |   | **Y |   |
| ame |                   |          | (   |   | (   |   | (   |   |
| *** |                   | **       | mm) |   | mm) |   | mm) |   |
|     |                   | *(mm)*** | *** |   | *** |   | *** |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| V1  | Cold bore tube,   | 73 x 1.9 | 20  | ± | 0.0 | ± | 15  | ± |
|     | left aperture     |          | 7.6 | 1 |     | 1 | 0.0 | 2 |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| V2  | Cold bore tube,   | 73 x 1.9 | -20 | ± | 0.0 | ± | 15  | ± |
|     | right aperture    |          | 7.6 | 1 |     | 1 | 0.0 | 2 |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| CL  | Helium sup/ret on | 38.1 x   | ±20 | ± | 13  | ± | 7   | ± |
| /LD | end vols (two)    | 1.65     | 7.6 | 2 | 1.1 | 2 | 5.0 | 2 |
| s   |                   |          |     |   |     |   |     |   |
| tub |                   |          |     |   |     |   | []{ |   |
|     |                   |          |     |   |     |   | .ma |   |
|     |                   |          |     |   |     |   | rk} |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| CL  | Helium sup/ret    | 38.1 x   | ±3  | ± | 21  | ± | 7   | ± |
| /LD | transfer lines    | 1.65     | 2.4 | 2 | 6.6 | 2 | 5.0 | 2 |
| x   | (two)             |          |     |   | ^c^ |   |     |   |
| fer |                   |          |     |   |     |   | []{ |   |
|     |                   |          |     |   |     |   | .ma |   |
|     |                   |          |     |   |     |   | rk} |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| m/c | Bus/helium tubes  | 63.5 x   | ±20 | ± | -13 | ± | 7   | ± |
|     | (two)             | 1.65     | 7.6 | 1 | 4.2 | 1 | 5.0 | 2 |
|     |                   |          |     |   |     |   |     |   |
|     |                   | 89.4 x   |     |   |     |   | []{ |   |
|     |                   | 1.65^a^  |     |   |     |   | .ma |   |
|     |                   |          |     |   |     |   | rk} |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| e   | Heat shield       | 17.2 x   | 27  | ± | -29 | ± | -5  | ± |
| ~1~ | sup/ret           | 1.0      | 0.0 | 2 | 0.0 | 2 | 6.0 | 2 |
|     | (connected)       |          |     |   |     |   |     |   |
|     |                   | 87.0 x   |     |   |     |   |     |   |
|     |                   | 3.5^b^   |     |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| e   | Heat shield       | 17.2 x   | -27 | ± | -32 | ± | -5  | ± |
| ~2~ | ret/sup           | 1.0      | 0.0 | 2 | 0.5 | 2 | 6.0 | 2 |
|     | (isolated)        |          |     |   |     |   |     |   |
|     |                   | 19.0 x   |     |   |     |   |     |   |
|     |                   | 1.65^b^  |     |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| W   | Cryostat          | 1055 x   | 0.0 | ± | -8  | ± | -32 | ± |
|     | (rotatable        | 61.5     |     | 3 | 0.0 | 3 | 2.0 | 3 |
|     | flange)           |          |     |   |     |   |     |   |
+-----+-------------------+----------+-----+---+-----+---+-----+---+
| W'  | Cryostat (flange  | 1008 x   | 0.0 | ± | -8  | ± | -29 | ± |
|     | mount)            | 59.0     |     | 3 | 0.0 | 3 | 2.0 | 3 |
+-----+-------------------+----------+-----+---+-----+---+-----+---+

Note a: Dimensions of flanges welded to tubes. The flange faces, when
they are present, are located at the interface.

Note b: Dimensions of tube behind interface. A transition section is
used to reach the metric interface dimension of 17.2 x 1.0.

Note c: transfer lines are tilted to facilitate gas flow; lead end
always higher.

All of the tubes move due to cooldown from 300 K to 4.3 K. The changes
in position are expressed as a combination of two movements. One
movement is that of the origin of the coordinate system, Figure 3. which
is centered between the two cold masses and moves down due to the
shrinkage of the cold masses and the support posts. The origin is
displaced 1.1 mm in the negative Z-direction (downward) and 16 mm toward
the center of the magnet in the Y-direction upon cooldown. The movements
of pipes and the cold masses reflect the fact that all are fixed to the
cryostat at the longitudinal midpoint, unless otherwise stated.

The other movement of each tube is with respect to the origin. That
movement is described in Table 2 for each tube. Tubes V1, V2, d, and m/c
all move in a similar manner due to the shrinkage of stainless steel and
their movements are expressed as a percentage of their distance from the
origin. Heat shield tubes e~1~ and e~2~ move due to a combination of
material shrinkages and their movements are expressed as explicit
distances toward (or away from) the origin.

***Table Cold changes in position at the D3 lead end on both sides of
the IP. The origin has been displaced 1.1 mm in the negative Z-direction
and 16 mm toward the center of the magnet in the Y-direction upon
cooldown. All pipes and the cold mass are fixed to the cryostat at the
longitudinal midpoint, unless otherwise stated.***

+------+--------------------+------------------------------------------+
| **   | ***Description***  | ***Change in Position With Respect to    |
| *Nam |                    | the Origin***                            |
| e*** |                    |                                          |
+------+--------------------+------------------------------------------+
| V1   | Cold bore tube,    | X: moves 0.3% toward origin.             |
|      | left aperture      |                                          |
|      |                    | Z: moves 0.3% toward origin.             |
|      |                    |                                          |
|      |                    | Y: moves 0.3% toward origin.             |
+------+--------------------+------------------------------------------+
| V2   | Cold bore tube,    |                                          |
|      | right aperture     |                                          |
+------+--------------------+------------------------------------------+
| C    | Helium gas vent    |                                          |
| L/LD |                    |                                          |
| stub |                    |                                          |
+------+--------------------+------------------------------------------+
| CL   | Cold mass supply   |                                          |
| xfer | transfer line      |                                          |
+------+--------------------+------------------------------------------+
| m/c  | Bus/helium         |                                          |
+------+--------------------+------------------------------------------+
| e1   | Heat shield        | X: moves 0.4% (1.1 mm) toward origin.    |
|      | sup/ret            |                                          |
|      | (connected)        | Z: moves 0.2 mm toward origin.           |
|      |                    |                                          |
|      |                    | Y: moves 4 mm away from origin. (Net     |
|      |                    | movement is 21 mm toward cold mass       |
|      |                    | center.)                                 |
+------+--------------------+------------------------------------------+
| e~2~ | Heat shield        | X: moves 1.1 mm toward origin.           |
|      | ret/sup (isolated) |                                          |
|      |                    | Z: moves 0.2 mm toward origin.           |
|      | Anchored at        |                                          |
|      | non-lead end       | Y: moves 6 mm toward origin. (Net        |
|      |                    | movement is 11 mm toward cold mass       |
|      |                    | center.)                                 |
+------+--------------------+------------------------------------------+

##  electrical connections

Figure 5 is a [schematic diagram]{.mark} of the main power to the D3
magnet coils. Labelling of the terminals follows the convention
specified in \[8\]. Figure 6 shows the instrumentation connections from
one cold mass through the IFS tube to the outside of the cryostat.

![](media/image7.wmf){width="6.25in" height="2.792361111111111in"}

TO IFS TO IFS

![](media/image8.wmf){width="5.995138888888889in"
height="5.336805555555555in"}

A bus/flex joint assembly of standard BNL design will be used in each
lead end volume to accommodate expansion and contraction of the powering
bus relative to the cold mass contraction and the bus motion in the DFBM
(see Figure 7). The electro-mechanical design inside the end volume will
connect the coil halves in series to the bus/flex joint assembly (see
Figure 5). Referring to the electrical schematic, note that the coils of
each cold mass are then series-connected by CERN either inside the DFBM
or before that point in the QQS; these designs are not within the BNL
work scope.

![](media/image9.wmf){width="5.802083333333333in"
height="3.8333333333333335in"}***Figure 7 Busbar interface at m/c bus
exit. Flex joint in neutral position. Dimensions are given in mm
\[inches\].***

Instrumentation supplied in D3 is shown in Table 5. All instrumentation
and control wiring is routed along and lashed to the flex joint, with
expansion loops between terminations and the flex joint lash point to
provide for differential thermal contraction internal to the magnet. The
instrumentation listed is for one cold mass; the other is a duplicate.
Each cold mass has its own dedicated IFS, discussed in more detail
below.

Table Instrumentation and control wiring exiting each cold mass through
its i stub and IFS. The external lengths are measured from the IFS
(Figure 8).

+------------------+------------+-------------------------------------+
| Lead             | Length     | Description                         |
+------------------+------------+-------------------------------------+
| Temperature      | 300 mm     | 2 twisted quads (total 8 wires, #30 |
| sensors          |            | AWG.)                               |
+------------------+------------+-------------------------------------+
| Voltage taps     | 300 mm     | 2 cables (3-#28 AWG wires each)     |
|                  |            |                                     |
|                  |            | red = "A" coil lead                 |
|                  |            |                                     |
|                  |            | black = "B" coil lead               |
|                  |            |                                     |
|                  |            | yellow = upper/lower coil crossover |
|                  |            | joint                               |
+------------------+------------+-------------------------------------+
| Quench heaters   | 300 mm     | 4 wires, #22 AWG                    |
+------------------+------------+-------------------------------------+
| Warm-up heater   | 300 mm     | 2 twisted pairs (total 4 wires, #26 |
|                  |            | AWG.)                               |
+------------------+------------+-------------------------------------+
| Liquid Level     | 300 mm     | 2 twisted quads (total 8 wires, #32 |
| Sensors          |            | AWG.)                               |
+------------------+------------+-------------------------------------+

There are two temperature sensors located within the cold mass on the
outside of the yoke near the longitudinal center. One of these sensors
is redundant. Temperature sensors are the short type thermometer
assemblies (36 mm x 12 mm x 4.2 mm) typically used by CERN \[9\]. The
sensors have been calibrated and supplied to BNL by CERN.

The 3-wire voltage tap cables consist of three Tefzel-over-Kapton
insulated wires within an outer helical wrap of 0.04 mm thick Kapton.
The voltage tap leads are soldered to the "A" and "B" leads and to the
crossover splice between upper and lower coils for each aperture, as
close as possible to the lead end of the coils. Tefzel is used only as a
convenience for color coding and Kapton retention; no credit is taken
for insulating properties.

The quench protection heater leads power the Q.P. heaters in two
independent circuits to create a level of redundancy in case of failure
in one circuit.

Two yoke warm-up heaters are located within the lead end volume.

All D3 magnets have helium level sensors provided in the lead end volume
which are used to control the cryogenic operation of D3. Two sensors are
provided for redundancy. The lead end of D3 is always the higher end.

The instrumentation wiring exits the end volume through the i stub into
the IFS (instrument feedthrough system), separating from the main power
buswork on the flex joint within the end volume. The IFS is a copy of
the CERN design to the extent possible. It exits the cryostat in the
standard way (see Figure 8), but there are notable exceptions: the
stainless tube from the cold mass to the thermalisation point is larger
in diameter consistent with the wire sizes used by BNL, there are two
feedthroughs per cryostat (one per cold mass), and the 40-pin
feedthrough plate is attached by CERN after magnet shipment. A short
section of tube, 206 mm OD x 2 mm wall thickness, is added to the top of
each standard flange. The tube terminates 51 mm above the joint between
the tube and flange in the vacuum vessel wall. The centerline of the
flange is located ±20° off the top center line of the vacuum vessel and
832mm back from the lead end flange. This is shown on the vacuum vessel
drawing; §8, ref\[c\]. At least 300 mm of instrumentation wire length
![](media/image10.wmf){width="5.875in"
height="3.1756944444444444in"}will be available for connection to the
40-pin feedthrough plate.

***Figure 5. [IFS flange on the vacuum vessel]{.mark}. Dimensions are in
mm \[inches\]. A tube of 206 mm OD and 2 mm wall thickness extends 51 mm
above the tube-flange joint.***

# LBRS interfaceS -- NON-LEAD END 

The installation connections needed at the non-lead end are the beam
screens, the electrical connections to the Undulator, the piping
connections from the transfer lines to the Undulator and the remaining
D3 cold mass, and the heat shield, MLI blankets, and cryostat closure
joining to the Undulator.

## [Cold bore tube, beam screen and warm-to-cold transition]{.mark}

CERN will design and provide beam screens and warm-to-cold transitions
(WCT), one of each per cold mass in the D3 magnet. They will be
installed after the magnet arrives at CERN. The spaces indicated in
Figure 10 are reserved for the cold bore -- beam screen interface (#1 in
Figure 10), WCT -- heat shield interface (#2), and WCT -- vacuum closure
interface (#3) are shown.

![](media/image11.wmf){width="6.5in" height="6.5in"}

***Figure 6 Reserved space for the beam screen interface and
warm-to-cold transition.***

## tube positions 

The warm coordinate positions and tubing diameters of the beam tubes,
helium tube stubs, and cryostat vacuum flange are given for the left and
right sides of the IP in Table [8]{.mark}. The cold Y-coordinate
positions are also shown. The cold X- and Z-cold coordinate positions
are the same as for the lead end (Tables 2 and 3). The local coordinate
system, which is referenced to the lead end volume moves with cooldown
as described in Section 3.2.

Table 1 Coordinate Positions for the D3 non-lead end on the left side of
the IP.

<table style="width:100%;">
<colgroup>
<col style="width: 8%" />
<col style="width: 22%" />
<col style="width: 14%" />
<col style="width: 8%" />
<col style="width: 4%" />
<col style="width: 7%" />
<col style="width: 5%" />
<col style="width: 8%" />
<col style="width: 5%" />
<col style="width: 8%" />
<col style="width: 5%" />
</colgroup>
<tbody>
<tr class="odd">
<td></td>
<td></td>
<td><em><strong>OD x Wall</strong></em></td>
<td colspan="8"><em><strong>Coordinate Positions</strong></em></td>
</tr>
<tr class="even">
<td><em><strong>Name</strong></em></td>
<td><em><strong>Description</strong></em></td>
<td><p><em><strong>Tube</strong></em></p>
<p><em><strong>(mm)</strong></em></p></td>
<td colspan="2"><em><strong>X (mm)</strong></em></td>
<td colspan="2"><em><strong>Z (mm)</strong></em></td>
<td colspan="2"><p><em><strong>Warm</strong></em></p>
<p><em><strong>Y (mm)</strong></em></p></td>
<td colspan="2"><p><em><strong>Cold</strong></em></p>
<p><em><strong>Y (mm)</strong></em></p></td>
</tr>
<tr class="odd">
<td>V1</td>
<td>Cold bore tube, left aperture<sup>a</sup></td>
<td>73 x 1.9</td>
<td>-207.6</td>
<td>±1</td>
<td>0.0</td>
<td>±1</td>
<td>10200</td>
<td>±3</td>
<td>10170</td>
<td>±3</td>
</tr>
<tr class="even">
<td>V2</td>
<td>Cold bore tube, right aperture<sup>a</sup></td>
<td>73 x 1.9</td>
<td>207.6</td>
<td>±1</td>
<td>0.0</td>
<td>±1</td>
<td>10200</td>
<td>±3</td>
<td>10170</td>
<td>±3</td>
</tr>
<tr class="odd">
<td>CL/LD stub</td>
<td>Helium sup/ret on end vols (two)</td>
<td>38.1 x 1.65</td>
<td>±207.6</td>
<td>±2</td>
<td>131.1</td>
<td>±2</td>
<td>10200</td>
<td>±2</td>
<td>10170</td>
<td>±3</td>
</tr>
<tr class="even">
<td>CL/LD xfer</td>
<td>Helium sup/ret transfer lines (two)</td>
<td>38.1 x 1.65</td>
<td>±32.4</td>
<td>±2</td>
<td>140.4<sup>c</sup></td>
<td>±2</td>
<td>10200</td>
<td>±2</td>
<td>10170<sup>b</sup></td>
<td>±3</td>
</tr>
<tr class="odd">
<td>m/c</td>
<td>Bus/helium tubes (two)</td>
<td>25.4 x 1.65</td>
<td>±207.6</td>
<td>±1</td>
<td>-<mark>134.2</mark></td>
<td>±1</td>
<td>10200</td>
<td>±2</td>
<td>10170</td>
<td>±3</td>
</tr>
<tr class="even">
<td>W</td>
<td>Cryostat</td>
<td>1055 x 82.5</td>
<td>0.0</td>
<td>±3</td>
<td>-80.0</td>
<td>±3</td>
<td>9938</td>
<td>±3</td>
<td>9922</td>
<td>±3</td>
</tr>
</tbody>
</table>

Note a: "Left" and "right" apertures are defined as viewed from
[lead]{.underline} end.

Note b: Transfer lines anchored at non-lead end.

Note c: Transfer lines are tilted to facilitate gas flow; lead end
always higher.

Note d:

Note e:

(Yellow = to be verified)

***Table 2 Coordinate Positions for the D3 non-lead end on the right
side of the IP.***

<table style="width:100%;">
<colgroup>
<col style="width: 8%" />
<col style="width: 22%" />
<col style="width: 14%" />
<col style="width: 8%" />
<col style="width: 4%" />
<col style="width: 7%" />
<col style="width: 5%" />
<col style="width: 8%" />
<col style="width: 5%" />
<col style="width: 8%" />
<col style="width: 5%" />
</colgroup>
<tbody>
<tr class="odd">
<td></td>
<td></td>
<td><em><strong>OD x Wall</strong></em></td>
<td colspan="8"><em><strong>Coordinate Positions</strong></em></td>
</tr>
<tr class="even">
<td><em><strong>Name</strong></em></td>
<td><em><strong>Description</strong></em></td>
<td><p><em><strong>Tube</strong></em></p>
<p><em><strong>(mm)</strong></em></p></td>
<td colspan="2"><em><strong>X (mm)</strong></em></td>
<td colspan="2"><em><strong>Z (mm)</strong></em></td>
<td colspan="2"><p><em><strong>Warm</strong></em></p>
<p><em><strong>Y (mm)</strong></em></p></td>
<td colspan="2"><p><em><strong>Cold</strong></em></p>
<p><em><strong>Y (mm)</strong></em></p></td>
</tr>
<tr class="odd">
<td>V1</td>
<td>Cold bore tube, left aperture<sup>a</sup></td>
<td>73 x 1.9</td>
<td>207.6</td>
<td>±1</td>
<td>0.0</td>
<td>±1</td>
<td>-10200</td>
<td>±3</td>
<td>-10170</td>
<td>±3</td>
</tr>
<tr class="even">
<td>V2</td>
<td>Cold bore tube, right aperture<sup>a</sup></td>
<td>73 x 1.9</td>
<td>-207.6</td>
<td>±1</td>
<td>0.0</td>
<td>±1</td>
<td>-10200</td>
<td>±3</td>
<td>-10170</td>
<td>±3</td>
</tr>
<tr class="odd">
<td>CL/LD stub</td>
<td>Helium sup/ret on end vols (two)</td>
<td>38.1 x 1.65</td>
<td>±207.6</td>
<td>±2</td>
<td>131.1</td>
<td>±2</td>
<td>-10200</td>
<td>±2</td>
<td>-10170</td>
<td>±3</td>
</tr>
<tr class="even">
<td>CL/LD xfer</td>
<td>Helium sup/ret transfer lines (two)</td>
<td>38.1 x 1.65</td>
<td>±32.4</td>
<td>±2</td>
<td>140.4<sup>c</sup></td>
<td>±2</td>
<td>-10200</td>
<td>±2</td>
<td>-10170<sup>b</sup></td>
<td>±3</td>
</tr>
<tr class="odd">
<td>m/c</td>
<td>Bus/helium tubes (two)</td>
<td>25.4 x 1.65</td>
<td>±207.6</td>
<td>±1</td>
<td>-<mark>134.2</mark></td>
<td>±1</td>
<td>-10200</td>
<td>±2</td>
<td>-10170</td>
<td>±3</td>
</tr>
<tr class="even">
<td>W</td>
<td>Cryostat</td>
<td>1055 x 82.5</td>
<td>0.0</td>
<td>±3</td>
<td>-80.0</td>
<td>±3</td>
<td>-9938</td>
<td>±3</td>
<td>-9922</td>
<td>±3</td>
</tr>
</tbody>
</table>

Note a: "Left" and "right" apertures are defined as viewed from
[lead]{.underline} end.

Note b: Transfer lines anchored at non-lead end.

Note c: Transfer lines are tilted to facilitate gas flow; lead end
always higher.

Note d:

Note e:

(Yellow = to be verified)

# LBRB -- Tunnel Floor interfaces

Figure 11 is a bottom view of the cryostat, showing the positions of the
internal support posts and the recesses in the CERN vacuum vessel
castings which interface with the support jacks. The three internal
support posts are positioned at the longitudinal center of the vacuum
vessel and 141.5 inches (3594 mm) to either side of center. The support
posts attach to CERN vacuum vessel castings which are integral to the
vessel at the three locations. The two cold masses inside the vessel are
supported on three transverse beams which are connected to the top of
the posts, one beam at each post location. Cold mass sliding is
accomplished at the interface between cradle and beam, and the two cold
masses are able to slide independently of one another. This design was
driven by the possibility of less than ideal cryogenic system operation
and allows for differences in temperature between the two cold masses.
An side benefit is that all three CERN posts can be fixed at the lower
end, simplifying construction. The heat shield is able to slide relative
to the fixed end posts.

To support the cryostatted magnet assembly, CERN \"PMPS\" jacks will be
used between the floor and the bottom surface of the two outboard vacuum
vessel castings. The castings (and the CERN-supplied vacuum port covers)
are designed with recesses into which BNL will fit GE-45-SX spherical
washers to mate with the jacks. Two jacks will be used at one end of the
magnet and one jack at the other. The single jack is located below the
magnet midpoint and interfaces with the recess and washer in the CERN
supplied port cover. The jacking points are located coincident with the
longitudinal center positions of the posts.

The central cold mass support post is partially reacted by the beam
stiffness of the vacuum vessel but is shimmed differently from the end
posts to eliminate mid-point sag of the cold masses inside. The midpoint
jack support to the tunnel floor at this location can be used to bring
the cold mass to a straight, level condition during tunnel installation
if further adjustment is necessary.

The outboard floor jacks are capable of resisting axial loads resulting
from unbalanced bellows forces due primarily to the vacuum load.
Therefore, these forces are transmitted to the tunnel floor through the
jacks rather than reacted to adjacent magnet elements.

![](media/image12.wmf){width="4.125in" height="3.4555555555555557in"}

***Figure 7 Jack Locations on the bottom of the LBRB cryostat.
Dimensions are given in mm \[inches\].***

# LBRB -- Alignment System interfaces

The location of the magnetic field center of the cold mass within the
vacuum vessel is known by taking measurements of the cold mass fiducials
on the shell and on the end volumes during fabrication and transferring
these data to cryostat fiducial locations at the Taylor-Hobson (T-H)
spheres in accordance with the CERN preferred method of surveying. The
cold mass position relative to the T-H spheres will be measured at BNL.
The documentation package shipped with each magnet will include the
survey information taken during manufacture. The cold mass position can
be checked after shipment to CERN by viewing the end volume and T-H
fiducials and comparing the measurements with the data supplied by BNL.

The nominal locations of the Taylor-Hobson spheres with respect to the
magnetic axis of the dipole magnet are given in Figure 12.

![](media/image13.wmf){width="5.133333333333334in" height="5.75in"}

***Figure 8 Fiducial locations on the LBRB cryostat. Dimensions are
given in mm \[inches\].***

# list of drawings

  ------- --------------- --------------- ---------------------------------
          ***LHC Drawing  ***BNL Drawing  ***Title***
          No.***          No.***          

  \[a\]   To be assigned  TBD             Magnet Assembly, Tested

  \[b\]   To be assigned  TBD             Magnet Assembly, Cryostatted

  \[c\]   To be assigned  14060040-1      Assembly, D3

          To be assigned  14060040-2      Assembly, D3

  \[d\]   To be assigned  TBD             Assembly, Cold Mass

  \[e\]   To be assigned  TBD             Assembly, Electro-Mechanical

  \[f\]   To be assigned  14060174        Flange, m/c Pipe

  \[g\]   To be assigned  TBD             IFS Flange
  ------- --------------- --------------- ---------------------------------

# references

1.  Design Report for the Interaction Region Dipoles and RF Region
    Dipoles, Brookhaven National Laboratory, January 18, 2000.

2.  "Superconducting Beam Separation Dipoles: D1 (MBX), D2 (MBRC), D3
    (MBRS), D4a (MBRA), D4b (MBRB)," LHC Functional Specification,
    LHC-MBR-ES-0001.00.

3.  "Configurations of BNL-built LHC Dipole Magnets," Brookhaven
    National Laboratory, Magnet Note 586, December 7, 1999.

4.  BNL Magnet Division Specification, "LHC Dipole Magnet Beam Tube
    Material," LHC-MAG-M-1010,
    http://magnets.rhic.bnl.gov/maps/documents\\LHC-MAG-M-1010.pdf.

5.  "Design Standards -- Mechanical Engineering and Installations," LHC
    Quality Assurance Standard, LHC-PM-QA-402.00 rev 1.1, 15 November
    1999.

6.  "Arc Cryomagnet Extremities," LHC-LI-ES-0001, rev 2.0, 20 August
    1999.

7.  "Beam Separation Dipole D4 Cooling," LHC Cooling Specification,
    LHC-MBR-ES-0006.00.

8.  "LHC Magnet Polarities," LHC-DC-ES-0001, rev 1.1, 19 June 1999.

9.  Balle, C., "Mounting of Industrial Type Cryogenic Thermometers,"
    version 2.0, CERN, 19 Feb 1999.