1. ILC main dump issue AWLC 2017 6/26
Hello every one. I’m Yu Morikawa.
I’m engineer stuff of KEK.
Today, I would like to introduce ILC main beam-dump and talk about technical issues.
Yu Morikawa
2017/6/26
AWLC2017

2. Contents ・Base Design of ILC Main Beam-Dump ・What we should do
1.Current Status of R&D
2.ILC Main Beam　　
　　Dump design
・Main Beam-Dump Body
・Handling of Beam heat
・Plan from 2017 to 2019
・R&D Cooperation ⇒ J-PARC, CERN
3.R&D Plan
This slide shows contents of my talk.
At first I’d like to talk about current status of main beam dump R&D.
・Energy Deposition & DPA
・Temperature & Pressure
4.Ongoing Simulation
2017/6/26
AWLC2017

3. Base Design of ILC Main Beam-Dump
Upgrade
acceptable power
[SLAC] 2.2MW Water beam-dump
[ILC] 18MW Water beam-dump
【ILC Beam the highest power condition 】
Average beam power : 14MW , Peak beam power : 3.8GW
【Water beam-dump】
・Liquid power absorption medium and forced convection to extract the heat.
・2.2MW water beam-dump was developed and successfully operated at the SLAC.
・Design of 18MW Water beam-dump for ILC is proposed by Satyamurthy*.
At first, I want to explain the brief overview of ILC main beam dump
The highest beam power of ILC is 14MW with 3.8GW of peak power .
To safely absorb and dissipate this high power beam,
Water beam dump is proposed as ILC main beam-dump.
Most general Beam-dump is made up of solid power absorption material.
But extracting heat capacity of solid material is limited by thermal conduction.
So, with the increasing of beam energy and intensity, it becomes increasingly difficult to absorb and dissipate the beam.
Therefore, Beam dumps utilizing a liquid power absorption medium and forced convection to extract the heat
are ideally suited to manage high energy and high intensity beams.
From such a background,
water beam-dump was developed at the SLAC and successfully operated .
And design of 18MW water beam-dump for ILC is also proposed.
2017/6/26
AWLC2017
*P. Satyamurthy, et.al., NIM A 679 (2012)

4. Detailed design issues
What we should do?
Issues of extracting the beam heat are OK.
⇒There are some detailed design issues.
Detailed design issues
Window Durability : Erosion, Corrosion, Cavitation, Thermal shock,
Radiation Damages
Tritium management : Saturation activity of Tritium will reach 2.6×1014Bq
Hydrogen recombiner : H2 generated by water splitting
Remote Handling：Remote replacement of Beam-Window
Protection system : Plan for window broken, maintenance scenario.
Detail design group in KEK has been organized in early 2017.
【Current work】
・Revisit the previous studies done by 2012＊ and follow-up the simulations
・Checking other possibilities, graphite dump …
Considering the use of water beam-dump,
Issues of extracting the beam heat are OK and base conceptual design is already completed.
But, on the other hand, there are some detailed design issues.
Middle circle shows detailed design issues.
Window durability is one of the issues. In our design, Beam window separates the vacuum and compressed water.
Window is attacked water convection and, due to high power beam, we must consider cavitation, thermal shock, radiation damage.
Substances managements are also issues.
Due to using the water-absorption medium, tritium and hydrogen are generated. And these Substances require risk management.
To tackle these issues, detail design group in KEK has been organized in early 2017.
Current work is Revisiting the previous studies done by 2012 and following up the simulations.
And In parallel I’m checking other possibilities. If we can apply the solid type beam-dump as ILC main beam-dump, that’s better because water dump have some risks such as tritium and H2 management.
(because we have to deal with difficult problems such as tritium and H2 management in the water beam-dump.)
*P. Satyamurthy, et.al., NIM A 679 (2012)
2017/6/26
AWLC2017

5. Contents ・Base Design of ILC Main Beam-Dump ・What we should do
1. Current Status of R&D
2.ILC Main Beam　　
　　Dump design
・Main Beam-Dump Body
・Handling of Beam heat
・Plan from 2017 to 2019
・R&D Cooperation ⇒ J-PARC, CERN
3.R&D Plan
So, from this slide, I want to introduce the design of ILC main beam-dump, our R&D plan and ongoing simulations.
・Energy Deposition & DPA
・Temperature & Pressure
4.Ongoing Simulation
2017/6/26
AWLC2017

6. Main Beam Dump Body 【Beam Power @ 1TeV Beam operation】
・500GeV×2.79nC×2450Bunches×4pulses：13.7MW
【Dump Structure】
・Cylindrical Water Container(φ1.8m×11m：28m3).
・10bar compressed cooling water⇒boiling temperature 180℃
・3 pipes in container. 2 water inlets , 1 water outlet.
・Beam Window made of Ti-6Al-4V.
This slide shows Main Beam-dump body.
Maximum 14MW beam incident to this beam-dump.
The shape of the beam-dump is cylindrical, the diameter is 1.8m, the depth is 11m, and volume is 28m3.
This cylindrical container storess cooling water and this cooling water is compressed 10bar.
By compressing the 10bar, the boiling point of water rises to 180 celicious degree.
In addition, 3 pipes are built into the cylindrical container to make the cooling water convection.
In the 3 pipes, 2 green pipes are for the release of the coolant, and the pipe shown in red is outlet of coolant.
Shown in the dark blue part is beam window and Beam incident here. This window is made of titanium-alloy.
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AWLC2017

7. Main Beam Dump Body 【Water flow】 ・Vortex flow(Clockwise flow)
・Mass flow rate : 104.5kg/s each inlet
⇒flow velocity 2.17m/s
・Inlet water temp：50℃
【Beam Window】
・Thickness 1mm/diameter 300mm　
　⇒Tolerable Pressure 32bar
・300mm in diameter is necessary
to receive Beamstrahlung photon
・Beam sweeping is necessary to reduce
　max water temperature.(Sweep Radius 6cm)
Here I show the details of beam dump.
At first , it is about how the cooling water flows. The each inlet of the green pipes supply the cooling water in the opposite direction
so that the flow of the cooling water becomes vortex convection.
Cooling water is discharged from this green pipe, and making the clockwise vortex convection
as seen in the beam incoming direction.
The mass flow rate of this cooling water is kg / sec per each inlet pipe,
and it is corresponding to 2.17 m / sec , we assume that the temperature of cooling water is 50 ° C.
(Next, we will explain the shape of the beam window.)
The diameter of the beam window is 300 mm, and the thickness of the beam window is 1 mm.
It can withstand up to 32bar pressure.
This diameter of 300 mm is necessary to receive the beamstrahlung photons generated at the interaction point.
Also, in order not to concentrate the beam heat in the cooling water, Beam is swept on the circumference of a radius of 60 mm,
2017/6/26
AWLC2017

8. Beam energy deposition in water & window
1 pulse
1 pulse
238J/cm3 , Z=180cm
Deposited energy density in cooling water
(r:from window-center,z:beam-direction)
This slide shows simulation results of the beam energy disposition.
The figure on the left shows the beam energy deposition in cooling water,
the horizontal axis is the distance in the beam incidence direction,
and the vertical axis is the distance from the beam window center.
The portion of high deposition density is indicated by this red color.
The maximum energy deposition occurred at a depth of 180 cm in the direction of incidence from the window,
It becomes 238 J / cm 3.
The figure on the right is energy disposition in the window,
the horizontal axis shows the distance from the window center,
and the vertical axis shows the deposition density.
Here, the amount of deposition density becomes maximum at a beam sweep radius of 6 cm.
Beam energy deposition in Beam Window
P. Satyamurthy, et.al., NIM A 679 (2012)
【Maximum Energy Density】 Cooling water ⇒ 238J/cm3 (z = 5Xo= 180 cm)
Window ⇒ 21J/cm3 (r = 6 cm, sweep radius)
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AWLC2017

9. Temperature distribution in water & window
Beam Entry (Max Temp)
This slide shows simulation results of the temperature distribution of the cooling water and the window when the beam is incident.
The figure on the left is the temperature distribution in the cooling water.
The red circle corresponds to the region where the swept beam enters.
Here, the temperature in the cooling water is maximized, and its temperature is estimated at 155 ° C.
Since boiling point of cooling water is 180 ℃, boiling does not occur.
The figure on the right is the temperature distribution of the window.
A high-temperature region is formed on the circumference by beam sweep,
and Maximum temperature is estimated to be 74 ° C at the maximum.
Both values ​​are acceptable values ​​as temperature values.
Temperature distribution of cooling water
＠maximum longitudinal power point : z=2.9m
Temperature Distribution of Window
P. Satyamurthy, et.al., NIM A 679 (2012)
【Maximum Temperature】 Cooling water ⇒ 155℃(z = 8.1Xo= 290 cm)
Window ⇒ 74℃ (r = 6 cm, sweep radius)
☆10bar compressed cooling water⇒boiling temperature 180℃
2017/6/26
AWLC2017

10. Contents ・Base Design of ILC Main Beam-Dump ・What we should do
1. Current Status of R&D
2.ILC Main Beam　　
　　Dump design
・Main Beam-Dump Body
・Handling of Beam heat
・Plan from 2017 to 2019
・R&D Cooperation ⇒ J-PARC, CERN
3.R&D Plan
And next, I want to talk about our R&D plan.
・Energy Deposition & DPA
・Temperature & Pressure
4.Ongoing Simulation
2017/6/26
AWLC2017

11. Main Beam-Dump R&D 【Detailed design issues】 【R&D Plan】
Window Durability , Tritium management ,Hydrogen recombiner ,
Remote Handling , Protection system …
【R&D Plan】
2017：Survey , full simulation and establish basic concept of Beam-Dump.
2018：Start designing of facility details. Mock-up test of window
2019：Designing of facility details. Mock-up test of window (focus on durability test)
【R&D Cooperation】
We are discussing with J-PARC and CERN in the ILC Beam-Dump R&D.
In this slide, I want to explain the our R&D plan.
As I explained earlier, Base conceptual design of water beam-dump is already proposed,
But there are still some detailed design issues.
Therefore, We are planning the R&D plan as follow.
In FY 2017, we will mainly investigate and simulate the main beam dump and establish the basic design.
Based on this basic design, We will conduct a detailed design of the facility and a model test of the window from FY 2018 to FY 2019.
In particular, we want to conduct modeling test in window 2018, durability test in fiscal 2019.
In the detail designing, we will collaborate with some companies.
In promoting these R&D, I think that cooperation with other laboratories is also important.
And we are discussing with J-PARC and CERN in the ILC Beam-Dump R&D.
2017/6/16
AWLC2017

12. Contents ・Base Design of ILC Main Beam-Dump ・What we should do
1. Current Status R&D
2.ILC Main Beam　　
　　Dump design
・Main Beam-Dump Body
・Handling of Beam heat
・Plan from 2017 to 2019
・R&D Cooperation ⇒ J-PARC, CERN
3.R&D Plan
This is last topics.
I want to introduce the ongoing simulations briefly.
・Energy Deposition & DPA
・Temperature & Pressure
4.Ongoing Simulation
2017/6/26
AWLC2017

13. Ongoing Simulations Revisit the previous studies* Window Simulations
Temperature distribution ,Thermal shock …
Recalculation with current ILC Beam status.
Window Simulations
Evaluating the window durability in the next 4 steps.
＊P. Satyamurthy, et.al., NIM A 679 (2012)
Step
Purpose
Tool 1
Beam Energy Deposition & DPA
FLUKA 2
Temperature & Pressure distribution
ANSYS Fluent(CFD) 3
Thermal shock of window
ANSYS Autodyn 4
Stress including step 2 and 3 results
ANSYS Mechanical
Investigate other possibilities
Solid type beam dump e.g., Grapgite?
This slide shows my simulation direction.
First of all, Purpose of my simulation is evaluating the Window Durability.
For this purpose, I think that next 4 steps are necessary.
1.1st step is evaluating Beam Energy Deposition and DPA in window.
For this purpose, I’m using FLUKA.
2.2nd step is evaluating the window temperature and pressure distribution.
To evaluate this, I’m using ANSYS Fluent. ANSYS Fluent is Computational Fluid Dynamics Package.
This step is on going work. now, I’m simulating the same situation as ILC Beam Dump Paper,
and try to reproduce the same results.
(I will check whether my results agree with those of ILC Beam Dump Paper.)
3.3rd step is evaluating the thermal shock of window. I will using ANSYS AUTODYN for this purpose.
4.4th step is final step and aim to evaluating the window stress including step2 and step3 results.
Based on these steps, I would like to decide the details of window design and the window exchange frequency.
(I would like to refer to these results for window designing and window exchange frequency.)
Today’s report is mainly focused on step1 and step2 results.
I explain the my evaluation results of Beam Energy Deposition and DPA first,
And next, I explain the water temperature simulation which is work in progress.
2017/6/16
ILC Beam-Dump

14. Beam Energy Deposition & DPA
FLUKA Simulations
I’m simulating the Beam energy deposition.
To evaluate the Beam energy deposition, I’m using the FLUKA.
2017/6/16
ILC Beam-Dump

15. Energy Deposition – Side View
[Energy Deposition in water]
e-/e+ Beam
500GeV(18MW) NIM Paper Status
Vertical axis(cm)
Energy Deposition(J/cm3)
This slide shows typical figure of energy deposition.
The below figure is side view of Energy deposition distribution.
Due to beam sweeping, we can see two high value lines along longitudinal direction.
Beam sweep φ 12cm
Longitudinal Slice
Longitudinal axis(cm)
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ILC Beam-Dump

16. Energy Deposition – Front View
500GeV(18MW) NIM Paper Status
[Energy Deposition in water]
High density:235J/cm3
Zoom up
Vertical axis(cm)
Energy Deposition(J/cm3)
Horizontal axis(cm)
Transverse Slice
This slide shows front view of energy deposition distribution.
The upper left figure shows transverse sectional view of energy deposition.
Beam incident to 35cm above from center of Beam-Dump body and deposition distribution is also shifted to upside.
The figure in the upper right is a energy deposition figure that close to high deposition density region.
We can see High deposition density (is observed) along the beam sweeping path.
Bottom right figure shows Another important effect which is caused by the asymmetric cross-section of the ILC beam .
When the beam is swept, the energy density is not uniform radially. In other words,
Even if on the beam sweeping path, energy deposition density is different depending on the azimuth.
So, we can see particularly large deposition density in the upper and lower part of the vertical.
My estimation of Maximum Beam-energy deposition density is 235J/cm3.
e-/e+ Beam
ILC Beam is very flat : σx >> σy
Energy Deposition Density is not uniform radially
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ILC Beam-Dump

17. Temperature & Pressure distribution
ANSYS Fluent Simulations
Report of Fluka simulations are finished.
So, Let’ s move on to step2 simulation:ANSYS Fluent Simulation report.
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ILC Beam-Dump

18. Water Velocity
Water velocity
This slide shows my simulation result of water velocity.
The flow of the cooling water simulated becomes vortex convection.
・Mass flow rate of cooling water is 104.5kg/s in each of the inlet headers.
・Water temperature is 50℃
2017/6/16
ILC Beam-Dump

19. 2D-Temperature distribution
@ Max Longitudinal Power point (z=290cm)
Temperature Distribution
The fluctuation of Max temperature
Δ30K
・Deposited Beam-heat is
・Max temperature my results 423K ⇔ NIM paper* 428K
・The fluctuation of Max temperature　my results Δ30K ⇔ NIM paper* Δ30K
⇒Now I’m checking my calculation to get more consistent results.
This slide shows temperature distribution of water and the fluctuation of maximum temperature.
In terms of Maximum temperature and fluctuation of maximum temperature,
My result is relatively close to NIM paper analysis.
But there is difference in the detail so Now I’m checking the my calculation to get more consistent results.
From these results, Our simulation method is being established.
＊P. Satyamurthy, et.al., NIM A 679 (2012)
2017/6/16
ILC Beam-Dump

20. Summary 1.Water Beam-dump is proposed as ILC Main Beam-Dump
・This design can accept 18MW Beam power.
・Some detailed design issues. e.g., window durability ,tritium …
2. What we should do.
・Detail design group in KEK has been organized in early 2017.
・Detailed system design should be completed in a few years.
・Revisit the previous studies done by 2012＊ and follow-up the simulations of
　a heat, a mechanical stress, a radiation, ...
・We are discussing with J-PARC and CERN in the ILC Beam-Dump R&D.
This slide is summary of this talk.
At first, water Beam-dump is proposed as ILC Main Beam-Dump
This design can accept 18MW Beam power but some detailed design issues still remain
These detailed system design should be completed in a few years.
Therefore, detail design group in KEK has been organized in early 2017.
And now, we are revisiting the previous studies done by 2012 and following up the simulations.
＊P. Satyamurthy, et.al., NIM A 679 (2012)
2017/6/16
ILC Beam-Dump

21. Slides for Discussions
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AWLC2017

22. Beam Parameters ・Simulate the all ILC stage.
ILC Beam
250GeV
New stage 2017
500GeV
TDR baseline
Lum. upgrade
1TeV
Energy upgrade
NIM Paper
Beam Energy
125GeV
Electrons per Bunch
2x1010 (3.2nC)
1.74x1010 (2.79nC)
Bunches per Pulse
1312
2625
2450
2820
Beam Size
σx = 2.42mm, σy = Beam Dump entrance
Beam divergence
Dump entrance
Momentum spread
0.2% Beam Dump entrance
Pulse length
0.727ms
0.961ms
0.897ms
0.95ms
Pulse Energy
0.52MJ
1.05 MJ
2.10 MJ
3.41 MJ
4.5MJ
Rep rate
5Hz
4Hz
Average Power
2.6 MW
5.25 MW
10.5 MW
13.7 MW
18MW
This slide shows Beam parameters I simulated.
Basically I simulated the all ILC stages and I also simulated the same conditions as NIM paper to check the my results.
Among the ILC stages, The highest fluence condition is 500GeV Lum.upgrade stage and The highest power condition is 1TeV Energy upgrade stage.
The highest Fluence
The highest Power
・Simulate the all ILC stage.
・To check the my results, simulate the same conditions as NIM paper＊
＊P. Satyamurthy, et.al., NIM A 679 (2012)
2017/6/16
ILC Beam-Dump

23. Maximum Deposition Density in Water
Max Density
235J/cm3
This slide shows Maximum Deposition density.
Center graph showing the maximum deposition density in each longitudinal point.
In my result of NIM paper condition, Maximum value of deposition density is 235J/cm3 and maximum value point is z = 188cm.
This values are pretty much the same results as NIM paper analysis.
・Max Density 235J/cm3 is pretty much the same results as NIM paper(237J/cm3).
2017/6/16
ILC Beam-Dump

24. Longitudinal Power in Water
Radially Integrate
54kW/cm
This graph shows longitudinal power , this longitudinal power is radially integrated value of energy deposition density .
Longitudinal power is important, because, According to NIM paper’s analysis, the highest water temperature is observed at Maximum longitudinal power point.
In my result of NIM paper condition, Maximum value of longitudinal power is 54kW/cm and maximum value point is z = (8 times radiation length, in a number it is)290cm.
This values are the same as NIM paper analysis.
・Max Longitudinal power 54kW/cm is the same results as NIM paper(54kW/cm).
2017/6/16
ILC Beam-Dump

25. FLUKA simulation Compare My results and NIM paper
1TeV NIM Paper Status
My Results
NIM paper
Max Energy Deposition Density
In water
235 J/cm3
@z=188cm
238 J/cm3
@z=180cm
Max Longitudinal Power in water
54kW/cm
@z=290cm
In Window
22.5 J/cm3
21 J/cm3
Total Deposition Power in Window
25W
This slide shows whether my results are consistent with NIM paper’s analysis.
Center table is comparing with my results and NIM paper results.
As table shows, all values are almost same as NIM paper’s analysis.
・My results are almost consistent with NIM paper results＊.
＊P. Satyamurthy, et.al., NIM A 679 (2012)
2017/6/16
ILC Beam-Dump

26. Energy Deposition in Window
Energy deposition in window (NIM paper status)
Energy Deposition
Energy Deposition(J/cm3)
Vertical axis (cm)
e-/e+ Beam
Horizontal axis (cm)
on sweep path
22.5J/cm3
Energy Deposition per pulse (J/cm3)
From this slide, I explain the window simulation results.
This slide show energy deposition in window.
As well as the case of water, We can see High deposition density (is observed) along the beam sweeping path.
And particularly large deposition value is observed in the upper and lower part of the vertical.
In my result of NIM paper condition, Maximum value of deposition density is 22.5J/cm3.
This value is pretty much the same results as 21J/cm3 which is NIM paper value.
・Max Density 22.5J/cm3 is much the same
results as NIM paper(21J/cm3).
2017/6/16
ILC Beam-Dump
Azimuth

27. DPA in window (NIM paper status)
DPA per pulse(×10-9)
Vertical axis (cm)
e-/e+ Beam
Horizontal axis (cm)
on sweep path
2.3×10-9/pulse
DPA per pulse
・It become the same distribution as Energy
deposition.
・Max DPA value is 2.3×10-9/pulse in NIM
paper status.
This slide shows DPA in window.
It become the same distribution as Energy deposition.
Max DPA value is 2.3×10-9/pulse in NIM paper status.
2017/6/16
ILC Beam-Dump
Azimuth