Detlef Swoboda
81925747
7/31/2017
12 services
The tunnel region at the location of the FP420 detectors presents a number of constraints
for the installation of instrumentation such as FEE, HV and LV power supplies, cooling
and detector gas supplies.
Simulations have shown (ref. LHC note 286) that the zone will be exposed to a
reasonably high radiation dose. A careful assessment of the possible locations and type of
instrumentation is therefore required. Provisionally space has already been reserved
underneath adjacent magnets upstream and downstream from the NCC where the LV and
HV supplies can be placed[yy = L0762023PL, L0762024PL, L0762045PL, L0762046PL,
L0722023PL, L0722024PL, L0722045PL, L0722046PL].Most of the machine
electronics is already placed in this volume and such reducing the available space. The
annual dose in this position under the arc magnets is expected to be between 10 and 20
Gy/yr. FEE like trigger electronics, alignment and detector positioning control can be
installed in cavities of the support beams of the NCC. In order to limit the radiation load
on the environment at most to the level estimated with the present configuration, an
envelop of adequate shielding (Pb plates) will be placed around the beam pipes and
detectors as described in section 7. It will also be feasible to place some equipment along
the LHC tunnel wall underneath the cable trays which run above the QRL line but the
radiation level will be somewhat higher than under the dipole magnets.
Figure xx: reserved instrumentation space below LHC main magnets.
Currently, active radiation monitoring instrumentation is being installed in the 420m
region of the LHC tunnel. These monitors will be operational at LHC startup and thus
provide valuable data to assess the real radiation levels in the area.
Detlef Swoboda
81925747
7/31/2017
At present no general services are provided in the LHC tunnel at the FP420 region.
Power- and controls- cables as well as tubes for FO will therefore need to be pulled from
the corresponding experimental area to this location. It is therefore proposed to install
additional cable trays next to the overhead rail of the monorail. This strategy has already
been used for the routing of the services for LHCf to both sides of point 1. FP420 can
reuse these trays which will have to be extended from the present 150m to 420m.
The FP420 power supplies and detector controls instrumentation could be connected to
the LHC machine power. This would assure the electricity supply as long as the LHC
machine power is available and reduce the cabling impact in the tunnel since additional
power cables would only need to be routed from the nearest RR alveoli at a distance of
about 200m.
Space has also been reserved in the RR13, RR17, RR53, RR57 alveoli on the 2 nd floor
level above the LHC magnets (Figure). This location is considered suitable for
installation of detector power supplies and electronics for the alignment monitoring
system.
Figure yy: Reserved rack space in LHC RRs.
The assessment of types and quantities of services needed for the FP420 detectors is still
rather difficult at this stage of the project. Those requirements which correspond to the
present estimation for each sub-system are summarized in table zz.
Detlef Swoboda
Sub-system
Gastof
Quartic
3D (Si)
General Cooling
Alignment
Positioning
Requirements
gas
FEE, DAQ
el. Power
FEE, DAQ
el. Power
Cooling
FEE, DAQ
el. Power
power, control
BPM, BLM,
WPS, other
Movement
drive, control
TTC, BST
Injection,
Dump
Timing
Interlocks
electrical power
HV
LV
Communication,
Detector RO
Miscellaneous
Instrumentation
Space
Table zz.
81925747
400Vac,
230Vac,
48Vdc?
16 ch HV 4kV
(timing)
36 ch HV
(tracking)
6 ch LV
(timing)
36 ch LV
(tracking)
F-O, Field-bus
Location
Detector station
Cryostat support beams
Under adjacent magnet
Cryostat support beams
Under adjacent magnet
Detector station
Cryostat support beams
Under adjacent magnet
Detector station,
Detector support table
RRs
Detector support table,
Under adjacent magnet
Counting rooms
Machine IF rack in
experiment counting
room
RR alveoli
7/31/2017
Comment
Secondary vacuum
UPS for controlled
shutdown?
Under adjacent magnets
Control from IP (CAN
bus?)
Under adjacent magnets
Control from IP (CAN
bus?)
ECR  FP420
RH-diodes:
MITSUBISHI
FU-427SLD-F1
Cameras, lights FP420
VME crate
Cell 12L/R @ IP1 & IP5
equivalent
each (5);
13.8 m tunnel wall;
Cell 11L/R @ IP1 & IP5
each (5)
Detector services requirements.
•Space available for
>= 2x24 fibres to each
station
Use BLM/BPM FEE?