## 5.2 Accelerator Systems (export this intro to section 2?)[^1]

Accelerator systems are divided between the standard "once per turn"
systems (located primarily in the Utility straight sections and IR's on
the Fermilab site) and the repetitive instrumentation in the long arcs
of bend magnets.

A completely conventional approach is taken to the standard utilities in
the straight sections. Warm iron/copper magnets use LCW cooling and
standard power supplies. Electronics and power supplies are located in
underground shielded instrumentation rooms that are accessible with beam
on. A 17ft tunnel, conventional power systems, and generous cable trays
provide the infrastructure for RF systems, injection and extraction
kickers and Lambertsons, beam crossovers, beam halo scraping, beam
current and beam profile monitoring, etc. Concentration of these major
subsystems at the Fermilab site makes maintenance and accessibility
requirements comparable to other Fermilab accelerators. The choice of
53MHz bunch crossing frequency supports standardization of the
instrumentation and controls with other machines in the FNAL injector
and minimizes EDIA and software costs associated with new designs. A
warm beam pipe is used everywhere except the IR triplet (and optionally
the superconducting RF) thus providing simple instrumentation
connections to the vacuum system. Quadrupole spacing in the straights is
typically 150m which leaves ample room for expansion. All the standard
components of the once-per-turn systems are technically equivalent to
those of recently completed projects: (Fermilab Main Injector warm
magnets, utilities and installation, B-factory/LHC RF, IR quads from the
USLHC collaboration, etc.). Thus adequately accurate cost estimates can
be obtained by scaling from these projects on a unit-cost basis.

In the long arcs of bending magnets the situation is different. The
once-per-turn subsystems and their cabling, power and cooling
requirements are absent. No LCW system is required. Only the repetitive
instrumentation and corrector power supplies at each of the 1760 "quad
locations" (every 135m around the ring at the location of beta-max in
each half-cell) is required. These electronics are located in a
radiation-shielded modules buried in "holes-in-the-wall" at each quad
location. Average power dissipation is approximately 15 W per meter of
tunnel. All cables for instrumentation and corrector magnets are
pre-assembled on the magnet and factory tested before installation.
Every other quad location (270m) cryogenic thermometry and a valve
controller are used to regulate the 50K shield flow. Every 10km there is
a walk-in alcove that contains conventional electronics racks and
provides network connection, tunnel safety systems, bulk DC power for
the instrumentation modules, and cryogenic instrumentation for the
cooldown valve box and located at the 10km points. The 10km alcoves are
associated with a tunnel egress point and may be accessible with beam
on.

Reliability is at a premium for the arc instrumentation due to the large
size of the machine. Repair technicians at a centrally located facility
require a 20mi drive to reach the surface facility and begin the access
into the tunnel. Minimum repair time will likely double the minimum 1.5
hour time needed to refill the machine and reaccelerate the beams. For
this reason fully redundant capability is provided for all
mission-critical subsystems in the arcs. Power distribution is provided
to each module by two independent loop feeders with auto-resetting
circuit breakers and remote disconnects. Two independent power supplies
are provided for each corrector magnet and control function. Redundant
network connections to each module are provided using both star and ring
topologies. The critical function of beam loss monitoring is provided by
redundant sensors read out from alternate quadrupoles modules, so that
even the death of a handful of control modules will not require
immediate maintenance.

### 5.2.1 Power Supplies

Stage 1 power supplies are summarized in the table below. Total power
supply requirements (both ramping and steady state) are less than a
quarter of the Fermilab Main Injector.

Table 5.2: Power Supply Summary for Stage 1 Machine

+----------------+------------+-------------+------------+------------+
|                | *Tr        | *IR         | *Straight  | *Corrector |
|                | ansmission | Quadrupole  | section    | Magnets    |
|                | Line Power | Power       | Warm       | (warm      |
|                | Supply*    | Supplies    | Magnet     | copper)*   |
|                |            | (sect       | Power      |            |
|                |            | 5.1.4)*     | Supplies*  |            |
+----------------+------------+-------------+------------+------------+
| Number         | 1          | 6 ?         | 16 approx. | 12,000     |
+----------------+------------+-------------+------------+------------+
| Location       | FNAL       | at          | Straights  | Quad       |
|                |            | Experiments |            | locations  |
+----------------+------------+-------------+------------+------------+
| Voltage per    | 62         | 10V typ.    | 1000V typ. | 100 Typ    |
| supply         |            |             |            |            |
+----------------+------------+-------------+------------+------------+
| Current per    | 100kA      | 25kA        | 200 typ    | 2A typ     |
| supply         |            |             |            |            |
+----------------+------------+-------------+------------+------------+
| Ramping MVA    | 6.2 MVA    | 1 MVA       | \-         | \-         |
| (tot)          |            |             |            |            |
+----------------+------------+-------------+------------+------------+
| DC Power       | 0.4 MW     | 0.6 MW      | 3.2 MW     | 2.1 MW     |
| (total)        |            |             |            |            |
+----------------+------------+-------------+------------+------------+
| LCW            |            |             | TBD        | \-         |
| Consumption    |            |             |            |            |
+----------------+------------+-------------+------------+------------+
| Quench         | 1 Circuit  | 2           | \-         | \-         |
| Detection      | at PS      | ci          |            |            |
|                |            | rcuits/quad |            |            |
+----------------+------------+-------------+------------+------------+
| Quench         | Dumps @    | 4           | \-         | \-         |
| Protection     | 20km       | h           |            |            |
|                |            | eaters/quad |            |            |
+----------------+------------+-------------+------------+------------+
| SC Current     | 100kA      | 150kA       | \-         | \-         |
| leads          |            |             |            |            |
+----------------+------------+-------------+------------+------------+
| **Peak Ramping | **12.3     |             |            |            |
| Supply Power** | MW**       |             |            |            |
+----------------+------------+-------------+------------+------------+
| **Total Power  | **6.3 MW** |             |            |            |
| Supply**       |            |             |            |            |
|                |            |             |            |            |
| **Power in     |            |             |            |            |
| Collision**    |            |             |            |            |
+----------------+------------+-------------+------------+------------+

#### 5.2.1.1 Main Transmission Line Power Supply

The low inductance (3uH/m, 0.6H ring total) and low stored energy
(10kJ/m, 3GJ total) of the single-turn transmission line magnet allow
the entire ring to be powered from a single supply \[ref Steve Hays
detailed write-up\]. The design voltage of 62V allows ramping the
machine up or down in 1000 seconds. The flattop current of 100kA exceeds
the 90kA required for the transmission line magnet to reach its design
field. The supply will be located on site at Fermilab in a shielded
underground room approximately 25' x 50' in size. The ramping power and
footprint of the power supply is comparable to one of the six Main
Injector power supply buildings. Superconducting current leads will be
located immediately adjacent to the supply to minimize power loss in
warm busswork. Superconducting busswork will carry the current through a
short connecting conduit to the transmission line magnets in a manner
identical to the MS6 test string \[ref Henryk\].

The power supply consists of two devices in series. One supply is used
for ramping voltage and transfers the inductive energy into and out of
the magnets. The second is used for holding the current during long
periods at flat top and injection, and provides only the voltage
necessary to overcome resistive losses in the current leads, warm
busswork, superconducting splices, and the shorting SCR switch across
the ramping supply. This approach minimizes the cost of the ramping
supply, simplifies the power distribution system, and moves the tightest
regulation and ripple requirements to the precision holding supply.

The RMS feeder load of 4,800KVA is less than one feeder cable for the
source. The design is based on paralleling 8500A modules of design
similar to Main Injector supplies. This approach permits spare modules
to be taken off line for repair, and permits the use of commercially
available 10kA DCCTs for current regulation. A 2-quadrant 12-phase SCR
bridge permits returning inductive power to FNAL as the magnets ramp
down. Ramping systems are designed to have RMS power sized to be halfway
between the peak (6.2MVA) and the RMS (3.1 MVA). This has proven to be a
reliable design methodology for similar supplies at Fermilab.

100kA RAMPING SUPPLY SCHEMATIC (S. Hays)

Figure 5.2.1: Ramping Supply Schematic

The holding supply is essentially a copy of the 100kA switching
converter \[ref.\] constructed for the R&D magnet test. The device
consists of ten 10kA DC-DC converter modules in parallel. The modules
use tape-wound cores and Schottky power diodes and switch at \~2 kHz. To
minimize output ripple the 10 modules will be phased to switch
sequentially, minimizing ripple and pushing the fundamental ripple
frequency up to \~20kHz. The switching will be phase locked to the
revolution frequency so that beam emittance growth due to power supply
ripple will be negligible. The control system for this switcher will be
integrated into that of the main ramping supply to simplify regulation
and load hand-off.

Picture of 10kA switching module at MS6 (Henryk)

Figure 5.2.2: 10 kA Switching supply module for MS6 String test

[\[\*\*\*DO WE NEED DISCUSSION OF EMITTANCE GROWTH AND SUPPLY
RIPPLE?]{.underline}

#### 5.2.1.2 IR Quad Power Supplies

Each IR requires 3 TBD 25kA TBD 5V TBD power supplies and current leads
for the super­conducting magnets of the inner triplet. These have
specifications similar to the LHC IR quad supplies and will be located
in a nearby shielded underground enclosure as discussed in sect \*\*\*.
A limited number of superconducting correctors may be included IR
triplet; these will require low voltage supplies, current leads, and
quench protection similar to the LHC. Outside the inner triplet, the
warm magnets and beam pipe will use warm correctors identical to those
of the arcs.

#### 5.2.1.3 Straight Section (Warm Magnet) Power Supplies

All F and D quadrupoles in each normal straight section are powered in
series by a single supply. Bend magnets are powered by the 100 kA
transmission line. Correction quads and orbit correctors (identical to
the arcs) are provided at each quad location. The power supplies are
located in shielded rooms (one per straight section) which contain
\~400kW of power supplies and are accessible with beam on. Given the
limited scope of these supplies it may be desirable to make them fully
redundant, especially those at the far side of the ring from FNAL. The
IR straight sections have a larger number of independently programmable
"tuning quads" with approximately the same total power and LCW usage as
a normal straight section.

#### 5.2.1.4 Corrector Power Supplies

The warm (air-cooled copper) correction magnets \[sect 5.1.3.3\]
dominate the power consumption in the arcs. The electronics module at
each quad location has 6-8 corrector magnet loads with a maximum
installed power of approximately 1400W. Average corrector power is
\< 1000W in a realistic operating scenario. At maximum current
approximately 90% of the power is dissipated in the magnets themselves
with the remaining 10% (\~150W) in the power supply converters.
Instrumentation and control power at each quad location is estimated to
be \~150W \[sect. \*\*\*\]. Power at this level can be passively
conducted away from the electronics and removed by the tunnel airflow of
\~1m/sec.

Concept Drawing for Quad Electronics Module

Including DC-DC Power Converters

and external heat sink

Figure 5.2.4.1: DC-DC Power Converters in each electronics module

Completely redundant DC-DC power converters are provided for each
corrector as well as control power for the instrumentation. Power can be
drawn from either of two redundant 1kV feeders that loop the ring. Power
supplies are connected in parallel at each load. Under normal
circumstances the load is shared and each power supply operates at \<
50% of rated load, encouraging long lifetimes. Under failure conditions
the load is taken over by a single supply which operates near its design
rating if the corrector magnet in question is on at 100%.

#### 5.2.1.5 Power Distribution to the Arcs

DC POWER DISTRIBUTION LOOP FEEDER SCHEMATIC

Figure 5.2.4: DC Power Distribution Loop Feeder Schematic

Medium-voltage 1kV DC is chosen for power distribution to the
electronics modules at each quad location. The DC is provided by 100A
bulk supplies every 10km located in racks of electronics in walk-in
alcoves. Two redundant bulk supplies are provided at each location, and
two independent distribution loops are provided to route the power to
the modules. Under normal conditions 25A is sourced in either direction
onto each of the 250MCM loop feeders, and less than 3% of the power is
lost in the distribution cabling. Under fault conditions both of the
bulk supplies at one of the 10km locations can fail, with the slack
being taken up by adjacent supplies in the loop feeders. A short-circuit
fault in one segment of the loop feeders can be tolerated by letting its
circuit breaker trip and relying on the remaining loop feeder. Each
module is protected with fault current limiting via automatically
resetting "solid-state fuses"\[ \] .

The advantages of DC power in this application are as follows. The main
power consumption is due to corrector power supplies that naturally
operate as DC-DC converters. These are more compact than
line-transformer based supplies, an important consideration for the quad
electronics modules. Modern DC-DC converters \[e.g. Vicor Web site\]
have the following parameters: power density 300W/in^3^, efficiency
\~90%, cost \~\$0.35/watt. In fact, essentially all modern AC devices
(fluorescent light ballasts, computers, high current welders, motor
controllers...) rectify the AC line power then chop the signal using
DC-DC techniques. Rectification requires bulky capacitors and produces
current spikes with power factor and noise problems that complicate AC
distribution. DC power distribution makes the most efficient use of the
copper in distribution cables, which is a major cost component in power
distribution. DC power also simplifies the design of loop feeders, which
may be powered from separate segments of the power grid without regard
to the relative phase of the incoming AC power. Finally, by
phase-locking the switching frequencies of the DC-DC converters to a
frequency near the revolution frequency of the machine, noise effects on
emittance growth can be essentially eliminated as discussed in section
5.2.xxx.

### 

### 

### 

### 

### 5.2.2 Cryogenics (insert Barry & Arkadiy's blurb)

### 5.2.3 Vacuum (maybe want to move this to end, it is logically separate)

### 5.2.4 Current Leads

Superconducting current leads are required for both the main
Transmission Line and IR quadrupoles. Current leads IR quadrupoles are
assumed to be identical to the commercially available HTS leads \[ref\]
used by the LHC IR's. The total current leads requirement for the Stage
1 machine is about 250kA-pair, or about 1/7 of the leads required by the
LHC \[3.5MA from Lynn Evans' stump speech\].

A single pair of 100kA current leads is required for powering the
transmission line. These could either be identical to the leads
\[Yuenian\] developed for the MS6 transmission line test facility, or
could be a High-Temperature Superconductor (HTS) version using the 50K
transmission line shield flow as the inter-stage temperature. The
cryogenic wall power associated with the conventional 100kA leads is
approximately 300kW. This could be reduced by a factor of 4-5 with HTS
leads \[Cryo Engr. Handbook\]. Payback time for the electrical cost
savings from HTS leads is approximately 3 years.

100kA CURRENT LEADS PICTURE (Yuenian)

Figure 5.2.1.4: 100kA Superconducting Current Leads Developed for the
MS6 Test string

### 5.2.5 Quench Protection

The only Superconducting magnets of the Phase I collider are the IR
Quadrupoles and the transmission line magnets. IR quads are on a small
number of individual circuits (6 per detector?) with standard quench
protection as described in sect \*\*\*.

#### 5.2.5.1 Transmission Line Quench Protection

The low inductance and low stored energy of the transmission line magnet
allows a simple and inexpensive quench protection system (fig. 1). The
magnets themselves require no internal quench detection or protection
circuitry. Ring-wide quench detection is performed by a single circuit
located at the power supply terminals. Quenches are detected by a
voltage imbalance at the power supply. When a quench is detected,
magnetic energy is extracted with a 1-second L/R time constant by
cryogenic "dump resistors" spaced at 20km intervals around the ring.
This keeps the peak temperature in the quenched section of the conductor
below 250k TBD as described in section 5.1.3.2.1. The dump resistors are
specialized 60m sections of transmission line which are deliberately
quenched to absorb the magnetic stored energy. Quench protection system
parameters are given in table 5.2.5.2. A detailed write-up is given in
\[Piekarz/GWF\].

![](media/image1.png){width="6.020833333333333in" height="3.61875in"}

Fig. 5.2.5.1 -- Quench protection of the Transmission Line Magnet
System.

Table 5.2.5.2 - Stage 1 Quench Detection and Protection Parameters

  ----------------------------------- -----------------------------------
  Transmission Line Current           100 kA

  Magnetic Stored Energy \@100kA      10 kJ/meter, 2100 MJ/ring

  Magnet Inductance at low field      3uH/m 600mH/ring

  Energy Dump Time Constant           1 second

  Peak Voltage To Ground during Dump  ± 3 kV

  I^2^t during dump                   5 x 109 Amp^2^Seconds

  Peak Temperature of Conductor       250K TBD
  During Quench                       

  Peak Pressure of Helium During      30 Bar TBD
  Quench                              

  Pressure relief during quench       At cool-down valves every 10km (no
                                      local relief)

  Effective Copper Cross Section of   3cm2 TBD
  Conductor                           

  Quench Detection Threshold          1 Volt

  Quench Detection Method (primary)   Deviation from V=LdI/dt at power
                                      supply terminals

  Quench Detection Method (backup)    Analog bucking with midpoint of
                                      current return bus

  Energy Dump Resistance              60 mΩ per location,

  Dump Switch Locations               at cryoplants and midpoint of arc
                                      (20km spacing)

  Dump Switches                       Quenched superconducting cables 65m
                                      long

  Superconducting Dump Switch         1:1 CuNi:NbTi "Switch Wire"
  Conductor                           soldered to SS bars

  Stainless Steel Bar Cryogenic Dump  65m long x 20cm2 SS 304 bars or
  Resistors                           pipe

  Final Dump Temperature after Dump   325K
  from 100kA                          

  LHe Required for recovery after     1600 liters (less if shield flow
  Dump from 100kA                     used for pre-cooling)
  ----------------------------------- -----------------------------------

![](media/image2.wmf){width="5.75in" height="1.8743055555555554in"}

Fig. 5.2.5.3 - Quench Protection Cell of the Transmission Line Magnet

Each string is divided into quench cells 20km long. When a quench is
detected, all dump switches open to divert the current into "dump
resistors" which absorb the magnetic stored energy with a 1 second L/R
time constant. Here the "dump switches" are deliberately quenched
sections of transmission line conductor built with Cu-Ni stabilized NbTi
"switch wire" which is designed to have a very high normal state
resistance. These dumps are efficiently recooled using helium from the
cryogenic shield flows and transmission line flows, with the warm gas
vented into the return header.

This quench protection system is notably simpler than those of other
accelerators. The LHC for example \[Refs PAC '99 papers\] requires a
crate of quench detection electronics in the tunnel underneath each
dipole. Each LHC magnet has more than 10 voltage taps and
instrumentation feed-throughs. The LHC also requires a much larger array
of energy dump resistors, dump switches, and current leads around the
circumference of the ring. Despite the larger machine circumference, the
quench protection system of the Stage 1 magnet should be simpler and
more reliable.

### 

### 5.2.6 Arc Instrumentation

The primary challenges of the repetitive instrumentation of the arcs are
cabling, reliability, and power distribution.

#### 5.2.6.1 Cabling in the Arcs

In the Fermilab Main Injector, the cable tray to each service building
contains 316 cables with a total cross sectional areas of 28 square
inches \[table 3.9.1 in FMI Design Report\]. Over 95% of these cables
service Beam Position Monitors (BPMs), Beam Loss Monitors (BLMs), Ion
Pumps, Corrector Magnets, and temperature and vacuum monitoring. The
installation, termination, and testing of these cables are a significant
cost and schedule item.

The Stage 1 most of the costs associated with installation and testing
of these cables are eliminated by ....

![](media/image3.wmf){width="4.055555555555555in"
height="4.2965277777777775in"}

Fig. 5.2.6.1 -- Schematic Cabling Layout on the Transmission Line
Magnet. Cables are preinstalled and factory-tested on the 65m magnets.
Each magnet has a 5m "extension cord" which jumpers to an electronics
module located in a hole in the wall at each quad location (135m
spacing).

![](media/image4.wmf){width="4.356944444444444in"
height="3.254166666666667in"}

Fig. 5.2.6.2 -- Location of the Electronics Module at each "Quad
Location" (placeholder)

#### 5.2.6.2 Beam Position Monitors (BPMs)

Both X and Y BPMs will be provided at each quad location. In the case of
the FMI it was determined that measurement of the second coordinate only
improved the closed-orbit distortion by 10% \[MI note 75\] and only a
single coordinate readout per quad location was provided. However the
added redundancy obtained by an independent readout of both coordinates
every half-cell will be beneficial given the small aperture and the long
travel distance required to repair failed BPMs. The BPMs are located at
half-cell boundaries between corrector magnets \[fig \*\*magnet end
layout\].

Button style beam pickups similar to those used on electron machines and
the LHC are adequate. These devices are significantly nonlinear outside
the central 30% of their aperture. Given anticipated closed orbit
distortions \<1mm this is not a problem. The arc magnets are designed to
support only a single beam orbit centered in the magnet. In the special
case of beam transfers where multiple off-axis orbits must be measured,
split-plate BPMs with much better linearity will be used.

BPM readout using either AM/PM or Log Amp electronics is acceptable. In
the case of Log-Amp readout both log(A/B) and log(A)+log(B) would be
digitized to provide both position and intensity readout. In the case of
AM/PM conversion a separate channel (possibly a log amp) is required to
provide intensity information. In either case an in-situ calibration is
desirable. The calibration circuit injects equal signals of adjustable
amplitude into both channels to accurately determine the zero-offset
response at different input strengths.

Digitization bandwidth is determined by the first turn and transient
response desired. A digitization rate \>25MHz can be supported by the
DMA channels of today's DSPs, with no external components other than the
flash ADC. A 10-bit digitization of log(A/B) would provide 20μm least
count resolution. Power dissipation for 4 channels of 10-bit 40 MHz
digitization would be 300mW total
(<http://products.analog.com/products/info.asp?product=AD9203>).

The cable run from the BPM to the quad electronics module is about 5m.
This is long enough that the signal must be terminated but short enough
that normal RG-58 can be used. No cable trimming for phase matching is
required if AM/PM electronics are selected.

#### 5.2.6.3 Beam Loss Monitors (BLMs)

The BLM function is mission-critical in the sense that no blind spots
can exist which would allow chronic beam loss to go undetected. (A rapid
intense beam loss at a single point will also cause large downstream
losses and possibly quench the magnet, and would therefore not go
undetected even if the BLM coverage was incomplete). We therefore choose
a cable style BLM \[ref \*\*\] which is essentially a long ionization
chamber that can provide complete coverage along the length of the
magnet. The cable will be all metal/ceramic construction (fig 5.2.6.1)
so that no gas-bottle changing will be required. For added redundancy,
two cable BLMs are provided each running the full length of the magnet
but read out at alternate quad locations. These provide complete
coverage even when the electronics module at a single location goes
*incommunicado*. Separate BLMs on each side of the magnet provide some
differential sensitivity to beam losses in each bore. Electronics
required include a 2kV/100μA Cockroft-Walton DC-DC converter module, an
op‑amp integrator, and a medium bandwidth \~100kHz 14-bit ADC. Power
dissipation should be \<2W.

![](media/image5.png){width="2.7958333333333334in"
height="3.203472222222222in"}

Fig. 5.2.6.3 -- Permanently Sealed Cable-style Beam Loss Monitor

#### 5.2.6.3 Vacuum Gauges & Ion Pump Power Supplies

The electronics module for each 135m half-cell requires 12 ion pumps
(22.5m pump spacing in each bore). Each pump requires a 5kV supply with
a starting current of up to 30mA but an operating current less than
100uA. The power for all 12 pumps is provided by single transformerless
bulk supply (a 5-stage Cockroft-Walton converter operating from the
1kVDC feeder). High voltage DC relays (Cotto 5501) isolate each pump and
give the capability of providing the full starting current sequentially
to each supply. Individual current readback on each pump is provided via
an array of line-powered V/F converters operating at HV with an
optically isolated data link to the DSP.

Ion Pump Power distribution in each half-cell.

Fig. 5.2.6.4 -- Ion Pump HV power distribution in each half-cell.

Failure of the bulk supply shuts down all ion pumps in a 135m half-cell.
Pumping from the NEG strip remains intact. This results in a 50x rise in
the pressure of one gas species (CH4) over the length of the half cell,
equivalent to a 3% rise in the average pressure of CH4 in the ring.
Redundancy in the ion pump power supplies is therefore unnecessary.

#### 5.2.6.4 Network & Clock Connections

The electronics module at each quad location contains a CPU which at
present could be a 1 GFLOP DSP with 128MB of RAM. This represents more
than enough horsepower to store, average, spectrum analyze, and
data-compress all digitized information before transmitting over a
conventional fiber network. The DSP, BLM and BPM electronics reside on a
single board.

For cost estimation purpose we have assumed eight direct point-to-point
fiber connections between each quad location and redundant network hubs
at located in the 10km alcoves. The fiber cable will be a pre-assembled
harness 5km long with 8-fiber breakouts at quad locations every 135m.
Installation will consist of laying the fiber in the cable tray
immediately below the electronics modules (fig 5.2.6.2) and plugging the
breakout into each electronics module.

Clock and Network Connections in the tunnel

including redundant hubs & clock fanouts at 10km alcoves

Figure 5.2.6.3: Clock and Network Connections in the tunnel

The long-haul fiber backbone interconnecting the 10km alcoves around the
ring will be buried in the power duct in the invert. This provides
additional radiation shielding to compensate for the longer distance of
the fiber runs.

#### 5.2.6.4 Miscellaneous Functions (creeping features) of the Quad Electronics Module

The networked DSP at each quad location provides the infrastructure for
additional features to be added at relatively low cost.

-   Tunnel temperature, humidity, and airflow transducers.

-   Integrated radiation dose monitor for the electronics module (FET +
    resistor).

-   RF modules to communicate with the cell phones and PDAs of tunnel
    crews.

-   Microphones for detecting quenches, tunnel dripping, and goofing-off
    crews.

-   Speakers to reprimand the above.

-   Cryogenic sensors and valve controls (presently estimated as a
    separate system)

-   Vacuum valve controls.

### 

### 5.2.6 Once-per-Turn Instrumentation

A number of standard systems occur only once per ring. In general these
can be copied from existing systems in the Tevatron and/or Main
Injector. The 53 MHz bunch structure and modest beam currents (\~1/3 of
Tevatron fixed target) provide no special challenges. These are
discussed more fully in
<http://www-linac.fnal.gov/~mccrory/papers/VLHC_Controls>.

Table 5.2.5.2 -- Once-per-Turn Instrumentation Parameters

  ------------------------ ------------- --------------- --------------------------
  **FUNCTIONOccurances**   **Readout     **Comments**    
                           Frequency**                   

  Tune Measurement         a few/ring    10 Hz           Use Arc Module DSP's for
                                                         FFT?

  Beam Current Toroids     1/ring                        Also on injection lines

  Sampled Bunch Display    1/ring        1 Hz             

  Fast Bunch Integrator    1/ring        1 Hz             

  Synchrotron Light        1/ring        1 Hz             
  Monitor                                                

  Ion Profile Monitor      2/ring        .1 Hz            Small beam size may be
                                                         challenging

  Flying Wires             1/ring         \~few per       
                                         store           
  ------------------------ ------------- --------------- --------------------------

### 

### 5.2.7 Beam Dampers (Lambertson/Marriner)

Beam stability in storage rings has relied on damper circuits for the
last 40 years....

#### 5.2.7.1 Distributed Resistive-Wall Dampers

#### 5.2.7.2 Bunch-by-Bunch Dampers 

#### 5.2.7.3 TMCI Damper (option)

### 

### 5.2.8 Radiofrequency Systems

#### 5.2.8.1 RF Parameters (injection)

#### 5.2.8.2 RF Parameters (ramping)

#### 5.2.8.3 RF Parameters (collision)

#### 5.2.8.4 SCRF Option

#### 5.2.8.5 Warm RF Option

[^1]: original file:
    [\\\\TDSERVER1\\project\\VLHC\\TDDoc\\DesignStudyReport\\05_Stage1_components\\Draft
    2\\originals\\5.2.AcceleratorSystems_March5.doc](../../../../../../../../project/VLHC/TDDoc/DesignStudyReport/05_Stage1_components/Draft%202/originals/5.2.AcceleratorSystems_March5.doc)