Infrastructure for SuperKEKB
Large beam current
SR, HOM
RF system
Buildings

Electricity

Infrastructure

Vacuum system
Cooling system
Buildings

Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

1

Infrastructure for SuperKEKB• Power consumption
9.4 A/4.1 A– Synchrotron Radiation (SR)
Short bunch length (3 mm)– Higher Order Mode (HOM)– Need many RF systems to support beam power– Magnets• Electricity– We have 4 substations for KEKB ring at KEK.

• Cooling system– Air cooled heat-exchanger+Chillers+Water pumps for vacuum chamber– Air cooled heat-exchanger+Water pumps for other components– VAPODINE system for collector cooling in klystrons• Buildings
Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

2

Upgrade of accelerator

ARES (8)No wigglers
at OhoSCC (12)

Oho

Nikko

Wigglers

LER
ARES (12)SCC (8)

Wigglers

HER

Tsukuba

ARES (16)Belle

BelleFuji
ARES (10)ARES (20)Layout of KEKB

Layout of SuperKEKB(design)
Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

3

Power consumption• Synchrotron radiation (SR)Nγ 4
N: no. of particles γ: Lorentz factor
PSR ∝ρ: bending radiusρ– Wigglers are assumed as a half of KEKB.
Beam current (A)Energy Loss (MeV)
SR power (MW)
Total power (MW)KEKB 2001
LER
HER
1.25
0.78
1.6
3.5
2.0
2.7
4.7

KEKB design
LER
HER
2.6
1.1
1.6
3.5
4.2
3.9
8.0

Super KEKB
LER
HER
9.4
4.1
1.2
3.5
11.3
14.3
25.6

– We keep 8 MW cooling capacity for vacuum chamber atpresent. (Cooling for RF dummy load provides 3.6 MW.)– SR power becomes 3 times larger than KEKB design.
– Cooling power of 25 MW is needed for SuperKEKB.
Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

4Power consumption (cont’d)• Higher Order Mode (HOM)
I2PHOM = T0 ⋅ κ (σ Z )NbBeam current (A)Number of bunches
Bunch length (mm)Loss factor (V/pC)
HOM power (MW)
Total power (MW)κ(σz): Loss factor σz: Bunch length
I: Beam current Nb: No. bunches

KEKB 2001
LER
HER
1.25
0.78
1153
5.5
5.7
2636
0.35
0.19
0.54

KEKB design
LER
HER
2.6
1.15120
4.026360.34
0.09
0.43

Super KEKB
LER
HER
9.4
4.1
5120
3.0
40
50
7.1
1.7
8.8

– RF cavities, resistive walls, bellows are considered forestimation of loss factors.
8.8 MW !
– We have to reduce loss factors since I and Nb are
determined by luminosity requirement.
Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

5

Power consumption (cont’d)• Beam power is a sum of SR and HOM power.
• RF system should compensate beam power.
• Many cavities and klystrons are needed !
• There are power loss at klystrons and cavities.
– Efficiency of klystrons (εkly) is ~60 % for AC plug power.
– Efficiency of cavities (εcavity) :• ~80% (LER ARES)• ~75% (HER ARES)• ~95% (HER SC)• Relation of beam power and AC plug power:
PAC = Pbeam ( ε kly.ε cavity )Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

6

Power consumption (cont’d)• RF system: Total AC power needs 73 MW.
Beam current (A)SR power (MW)HOM (MW)
Beam power (MW)AC power
Total AC power (MW)KEKB 2001
LER
HER
1.25
0.78
2.0
2.7
0.35
0.192.35
2.89
4.90
5.77
10.7

KEKB design
LER
HER
2.6
1.1
4.2
3.9
0.34
0.09
4.54
3.99
9.46
7.97
17.4

Super KEKB
LER
HER
9.4
4.1
11.3
14.3
7.1
1.7
18.4
16.0
40.0
33.0
73.0

• Magnets(include power supplies): 7.5 MW• Beam transport lines: 1.3 MW$180K/day• Total is ~100 MW for SuperKEKB.
(100/(150+25 MW) ~60 %)– including power consumption on infrastructures.
Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

7ElectricityTotal:150+25 MWˇ dˇ d(Oho substation)(Center substation)4 substations
for KEKBPS ˇ d(PS substation)

1 substation
for PS
1 substation
for injector&PFt H gAR ˇ dœ ı ˇ d

ˇ d(Photon substationsubstat(AR substation)(Nikko substation)

Y. Ohnishi (KEK) KEKB Review Committee Feb 26 20028

Electricity (cont’d)• Distribution of power consumption due to RF:– Fuji: 28.6 MW– Oho: 34.4 MW– Nikko: 10 MW• Substations: Oho, Nikko, AR(for AR and Fuji)• However, each substation is 32 MW capacity.
(AR substation has 51.5 MW capacity)• We assume that Proton Synchrotron (PS) will beshutdown before starting SuperKEKB.
• PS substation has 56 MW capacity.
Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

9

Cooling system• Klystron power loss is 32 MW out of 38.6 MW oftotal RF power loss.
• We have special cooling system for klystrons.
– VAPODINE system– The system is compact.

• SR and HOM power loss: 34 MW– Heat distribution is assumed to be uniform along ring.
– We consider 12 sections for cooling of vacuum chamber.
– Heat load for each section is ~3 MW.
– Air cooled heat-exchanger+Chiller+Pumps
Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

10

Cooling system (cont’d)• VAPODINE for klystrons (RF Group, H. Nakanishi)
Air cooled
heat-exchanger
collectorklystronReserve water tank
Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

11

Cooling system (cont’d)
Cooling system for vacuum chamber is :
 Air cooled heat-exchanger+Chiller+Pumps
Temperature Flow rate: 2000 l/min
controloChiller
 Incoming: 45 C.
o Outgoing: 24 C.
pump
Plate typeHeat-exchanger

Heat load

Air cooled heat-exchangerpump
Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

12

Cooling system (cont’d)• Cooling system for magnets, cavities, dummy loads is aircooled heat-exchanger+pumps. (No chiller)• The system is simple and reliable.

Air cooledheat-exchanger

Pumps

Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

Inside oftunnel

13Buildings• Buildings for vacuum chamber cooling system:– 4 Buildings exist at straight sections (Fuji, Nikko, Tsukuba, Oho) +additional 2 buildings for each arcs (2x4).
– Area of ~300 m2 is needed for chillers and pumps at each building.

• Buildings for RF systems– Total number of klystrons to be installed is 66.
– We must prepare buildings as early as possible to install RF units(klystrons, power supplies, dummy loads,…)• Buildings for R&Ds, test benches, temporary usage(?).

Y. Ohnishi (KEK) KEKB Review Committee Feb 26 2002

14