1. τ- Charm Vacuum System Preliminary
La Biodola - Isola d'Elba, Italy May 2013
τ- Charm
Vacuum System
Preliminary
Simone BINI, Fara CIOETA, Alberto CLOZZA

2. Injection System Layout
La Biodola - Isola d'Elba, Italy May 2013
Injection System Layout
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

3. Vacuum System First hypothesis on: DAMPING RING LINAC TRANSFER LINES
La Biodola - Isola d'Elba, Italy May 2013
Vacuum System
First hypothesis on:
DAMPING RING
LINAC
TRANSFER LINES
MAIN RINGS
τ- Charm - Injection System Vacuum preliminary S. Bini, F.Cioeta, A. Clozza

4. Number of Damping Ring Dipoles
La Biodola - Isola d'Elba, Italy May 2013
Number of Damping Ring Dipoles
Damping Ring
Parameter
Units
Value
Maximum Beam Energy
GeV 1
Maximum Beam Current mA 8
Dipole field T
1.7
Working pressure
mbar
1×10-9
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

5. La Biodola - Isola d'Elba, Italy 26-31 May 2013
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

6. La Biodola - Isola d'Elba, Italy 26-31 May 2013
Parameter
Units
Value
Total photon flux
s-1
6.5×1018
S.R. Desorption coefficient η
1×10-5
Surface specific thermal outgassing
mbar l s-1 cm-2
5×10-12
Vacuum chamber inner surface
cm2
1×105
S.R. Gas load
mbar l/s
2.6×10-6
Thermal Gas Load
3.5×10-7
Total Gas Load
3×10-6
Working pressure
mbar
1×10-9
Total needed net pumping speed
l/s
3000
Total SR power load W
400
Number of 120 l/s Ion Pumps 36
Total installed pumping speed
4320
Number of UHV gauges 9
Number of gate valves 4
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

7. DR Vacuum Pumps Positioning
La Biodola - Isola d'Elba, Italy May 2013
DR Vacuum Pumps Positioning
The Hypothesis is to insert a couple of ion pumps on each bending magnet
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

8. DR Gate Valves and Gauges Positioning
La Biodola - Isola d'Elba, Italy May 2013
DR Gate Valves and Gauges Positioning
Valves (4)
Gauges (9)
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

9. DR Pressure Profile Analysis
La Biodola - Isola d'Elba, Italy May 2013
DR Pressure Profile Analysis
τ- Charm - Injection System Vacuum Preliminary S. Bini, F.Cioeta, A. Clozza

10. DR Results Vacuum profile
La Biodola - Isola d'Elba, Italy May 2013
DR Results Vacuum profile
Simulations show that a mean pressure of about 3×10-9mbar is expected.
The Pressure profile for Damping ring has been simulated for nitrogen gas at 293K, taking into account thermal gas load too.
The SIP are assumed to be StarCell 120 l/s, connected to vacuum chamber by means of RF screened ports.
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

11. LINAC Requirements Zone Pressure RF Gun 10-10 mbar LINAC 10-9 mbar
La Biodola - Isola d'Elba, Italy May 2013
LINAC Requirements
Zone
Pressure
RF Gun
10-10 mbar
LINAC
10-9 mbar
RF WAVE GUIDES
10-8 mbar
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

12. Scheme of Pumping System
La Biodola - Isola d'Elba, Italy May 2013
Scheme of Pumping System
Pumping Station
τ- Charm - Injection Vacuum System S. Bini, F. Cioeta, A. Clozza

13. Transfer Lines Requirements
La Biodola - Isola d'Elba, Italy May 2013
Transfer Lines Requirements
TL Pressure
1×10-8 mbar
Vacuum Chamber cross section
Straight Φ 60 mm
PUMPING SPEED
120 l/s every 8 m
τ- Charm - Injection Vacuum System S. Bini, F. Cioeta, A. Clozza

14. Average Working Pressure[mbar]
La Biodola - Isola d'Elba, Italy May 2013
Main Ring
PRELIMINARY
Parameters
Values
Energy [GeV]
2.3
Current LL[A]
1.570
Current HL [A]
2.340
Average Working Pressure[mbar]
1x10-9
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

15. Machine Requirements No specific requests on vacuum pressure
La Biodola - Isola d'Elba, Italy May 2013
Machine Requirements
No specific requests
on vacuum pressure
Hp: 1x10-9 mbar
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

16. Vacuum System Dimensioning
La Biodola - Isola d'Elba, Italy May 2013
Vacuum System Dimensioning
Γ = 8.08×E×I×1020 (total photon flux)
LL HL
E=2 GeV
I=1.570A I=2.340A
ΓL=2.5×1021 photons/s
ΓH=3.8×1021photons/s
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

17. Gas Load Distribution along the Machine
La Biodola - Isola d'Elba, Italy May 2013
Gas Load Distribution along the Machine
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

18. Dipole Magnets As Synchrontron Radiation Sources
La Biodola - Isola d'Elba, Italy May 2013
Dipole Magnets As Synchrontron Radiation Sources
Total Irradiate Power: [kW]
~ 700 W/m
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

19. QH=1.5×10-4 mbar l/s Total Gas Load η=1×10-6 (desorption efficiency)
La Biodola - Isola d'Elba, Italy May 2013
Total Gas Load
η=1×10-6 (desorption efficiency)
1mbar l=2.5×1019molec. (conversion factor)
Q=Γ η / 2.5×1019 (gas load)
QH=1.5×10-4 mbar l/s
τ- Charm - Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

20. Mean Pressure & Pumping
La Biodola - Isola d'Elba, Italy May 2013
Mean Pressure & Pumping
<P>≈10-9 mbar (mean working pressure)
S=Q/P (pumping speed)
SH=1.5×105 l/s (HL total pumping speed)
L=325 m S0H= SH/L
S0H=460 l/sm (linear net pumping speed)
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

21. Possible Solutions La Biodola - Isola d'Elba, Italy 26-31 May 2013
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

22. La Biodola - Isola d'Elba, Italy 26-31 May 2013
Pumping System
The main process of gas desorption in beam operation is photodesorption i.e. desorption caused by SR
In order to evacuate the beam pipes we can use several approaches (all together if possible):
A distribuited pumping scheme using a strip-type nonevaporable getter (NEG) and we can use these pumps irrespective of the presence of magnetic fields.(The maximum Pumping Speed is 160l/s )*
Lumped NEGs and Sputter Ion Pumps must be used on the straight section .
Coating: NEG (Ti-Zr-V), TiN, Graphite
*Design and Construction of the SuperKEKB vacuum system – Yusuke Suetsugu,Ken.ichi Zanazawa, Kyo Shibata, Takuya Ishibashi, Hiromi Hisamatsu, Mitsuru Shirai, Shinji Terui – High Accelerator Research Organization (KEK), Japan
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

23. Pumping System Where possible to be verified
La Biodola - Isola d'Elba, Italy May 2013
Pumping System
In order to evacuate the beam pipes we can use several approaches (all together if possible):
Dafne Like Vacuum System:
Titanium Sublimators
Sputter Ion Pumps
Synchrotron Light Absorbers
Distributed Sputter Ion Pumps inside bendings (Maximum Pumping Speed mbar, no need of any reactivation)
Where possible
to be verified
*References: Brookhaven National Laboratory - Calderon ,PAC_1993
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

24. VACUUM CHAMBER DESIGN OF DAFNE WITH SYNCHROTON RADIATION DISTRIBUTION
La Biodola - Isola d'Elba, Italy May 2013
VACUUM CHAMBER DESIGN OF DAFNE WITH SYNCHROTON RADIATION DISTRIBUTION
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

25. BARC MAGNET DIPOLE BENDING BARC VACUUM CHAMBER
La Biodola - Isola d'Elba, Italy May 2013
BARC
MAGNET DIPOLE BENDING
BARC VACUUM CHAMBER
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

26. Synchroton Radiation into the Bending Magnet
La Biodola - Isola d'Elba, Italy May 2013
Two main parameters assist to select the vacuum chamber material:
the synchrotron radiation power density;
the secondary electron yield coefficient.
The material that fulfills these requirements is Aluminum. Moreover, a suitable water cooling must be adopted.
Synchroton Radiation into the Bending Magnet
RF Screen
Straight Section
Vacuum Pump
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

27. Disadvantages of NEG Coating
La Biodola - Isola d'Elba, Italy May 2013
Disadvantages of NEG Coating
Small absorbiting capacity of the coating can be a problem for relatively high gas-loaded machines;
Slow deposition rate and possible sediment
Reactivation Process every 8 hours is possible only by heating the vacuum chamber
NEG:150°C
Aluminum max 130°C
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

28. Ti27%V47%Zr26% Average Composition : Deposition Rate :
La Biodola - Isola d'Elba, Italy May 2013
VACUUM PUMPING STUDY OF TITANIUM-ZIRCONIUM-VANADIUM THIN FILMS
Yulin Li# and Simon Ho, LEPP, Cornell University, Ithaca, NY 14853, USA
Average Composition :
Ti27%V47%Zr26%
Deposition Rate :
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

29. DISTRIBUTED NEG CONSTRAINS
La Biodola - Isola d'Elba, Italy May 2013
DISTRIBUTED NEG CONSTRAINS
Activation is required approximately every month for continuos full-current operation (21 days SuperKEKB (Japan))
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

30. La Biodola - Isola d'Elba, Italy 26-31 May 2013
WIGGLER
If installed on the machine, They are intense Synchrotron Radiation sources.
There contribution to gas load must be very carefully evaluated.
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza

31. 2. It’s necessary to evaluate the Vacuum Chamber Impedance
La Biodola - Isola d'Elba, Italy May 2013
CONCLUSION
Many studies remain to be performed to confirm the choices
1. Deep interaction with other Systems (Beam Diagnostics, RF Feedback, Mechanics) is necessary to go ahead with the design of the machine
2. It’s necessary to evaluate the Vacuum Chamber Impedance
τ- Charm - Injection Vacuum System Preliminary S. Bini, F. Cioeta, A. Clozza