1. M. Calviani, A. Ferrari (EN/STI), P. Sala (INFN)
Progress report: Secondary Beam Production SBLNF meeting – 19th October 2012
M. Calviani, A. Ferrari (EN/STI), P. Sala (INFN)

2. M. Calviani, A. Ferrari, P. Sala
Outline
Update on the m fluence
Margins for the location of the ND
FLUKA implementation of the target “chase” design
First look at dose rate, absorbed dose and HEH fluence
First look at energy deposition
Ideas on potential neutrino target concepts
M. Calviani, A. Ferrari, P. Sala
19th October 2012

3. M. Calviani, A. Ferrari, P. Sala
Update on the m fluence
Margins for the location of the ND
FLUKA implementation of the target “chase” design
First look at dose rate, absorbed dose and HEH fluence
First look at energy deposition
Ideas on potential neutrino target concepts
M. Calviani, A. Ferrari, P. Sala
19th October 2012

4. Update on muon fluence Muons produced by pion/kaon decay:
Penetrate the ground after hadron stopper and could reach the ND  significant background for experiment
Critical parameters
Primary beam energy
Moraine density
Distance between target and ND
Design of hadron stopper
Discussed during 26th September meeting (link)
Target chamber
Decay pipe
Hadron stopper
Near detector
target
~26 m
(driven by production elements configuration)
~74 m
(to be driven by experimental requirements)
~10 m
~350 m (driven by m in ND – experimental requirements)
+ civil engineering constraints
M. Calviani, A. Ferrari, P. Sala
19th October 2012

5. M. Calviani, A. Ferrari, P. Sala
Update on muon fluence
Proton momentum
Muon range
100 GeV/c
~320 meters
110 GeV/c
~340 meters
120 GeV/c
~360 meters
Assumptions:
4.5*1013 p/pulse
1.9 g/cm3 moraine density
DP 100 m long
HS: 3 m core + 7 m Fe
Decay pipe
Hadron stopper
Moraine soil
No large safety margin for the location of the ND
~15% on moraine density (40 m moraine  20% density change)
No margin on energy!
Increase of Fe core length (10 m moraine  3.5 m Fe)
M. Calviani, A. Ferrari, P. Sala
19th October 2012

6. M. Calviani, A. Ferrari, P. Sala
Update on muon fluence
100 GeV/c case
Coherent production (very low cross-section) could result in ~100 GeV muons being produced
Additional meters would be required!
Monoenergetic 100 GeV/c muons
345 m
Muons produced from 100 GeV/c protons
320 m
Normalization at ~50 m from target
M. Calviani, A. Ferrari, P. Sala
19th October 2012

7. M. Calviani, A. Ferrari, P. Sala
Update on the m fluence
Margins for the location of the ND
FLUKA implementation of the target “chase” design
First look at dose rate, absorbed dose and HEH fluence
First look at energy deposition
Ideas on potential neutrino target concepts
M. Calviani, A. Ferrari, P. Sala
19th October 2012

8. Discussed during 26th September meeting (link)
M. Calviani, A. Ferrari, P. Sala
19th October 2012

9. Target station building and vault
Secondary beam line
FLUKA preliminary implementation:
Shielding thickness not optimized!
Hadron stopper
Target station building and vault
Target chase
Primary beam area
Target shielding
Decay pipe
Decay pipe shielding
Ground (moraine)
M. Calviani, A. Ferrari, P. Sala
19th October 2012

10. Target station design: FLUKA implementation
Target station building and vault
(covered by soil)
Top concrete shielding
Primary beam area
750 cm
Fe shielding
Target/focusing
Baffle
Ground (moraine)
M. Calviani, A. Ferrari, P. Sala
19th October 2012

11. Target station design: FLUKA implementation
Target station building and vault
200 cm
He vessel (medium blue)
Concrete shielding (red)
300 cm
Iron shielding (dark blue)
Target chase
300 cm
Target & horn/reflector
Ground (moraine)
M. Calviani, A. Ferrari, P. Sala
19th October 2012

12. Target station: Ambient dose equiv. H*(10)
Assumption: ultimate beam (R. Steerenberg, 26th Sept.)
120 GeV/c
3.6 s rep. rate
4.5*1013 p/pulse
240 kW
NB: 120 GeV/c out of question in the current layout!
Results:
≤10 mSv/h on top of the vault
~1 Sv/h on top of the first layer of shielding
Note:
Weak point in the present shielding design
To be corrected at the next iteration!
M. Calviani, A. Ferrari, P. Sala
19th October 2012

13. Target station preliminary design: H*(10)
Overall H*(10) view of the installation:
H*(10) at 15 m from beam axis (DP level) <1 mSv/h
Ground level ~20 m from beam axis
Dose rate after the dump mainly due to m (reduced activation!)
M. Calviani, A. Ferrari, P. Sala
19th October 2012

14. Target station preliminary design: H*(10)
Primary area:
Average around 5 mSv/h
Peak ~200 mSv/h through the baffle (5 cm radius)
~1 Sv/h on top of the first layer of shielding
Aperture (10 cm) between shielding blocks to evaluate effect of neutron penetration
M. Calviani, A. Ferrari, P. Sala
19th October 2012

15. Target station design: HEH and absorbed dose
High energy hadron fluence:
Important to have a look at this since the beginning (R2E)
Levels on the surface of the vault ≤107 HEH/cm2/year
Absorbed dose:
kGy/y on the gap above the first layer of shielding
~10 MGy/y inside the chase
~50 Gy/y on the concrete lining
M. Calviani, A. Ferrari, P. Sala
19th October 2012

16. Target station design: energy deposition
Region
kJ/pulse
kW (average)
Target
5.62
1.56
Top Fe shielding (layer 1)
48.32
13.42
Lateral Fe shielding
57.50
15.97
Bottom Fe shielding
55.42
15.39
Decay pipe shielding (total)
258.56
71.82
Decay pipe shielding (1st layer)
243.66
67.68
Hadron stopper (graphite)
159.54
44.32
Hadron stopper (iron)
123.70
34.36
Horn (total)
7.01
1.95
Reflector (total)
5.05
1.40
Target: ~1.5 kW
“Chase” iron shielding:
~50 kW deposited power
Air/He cooling probably necessary!
DP concrete shielding:
~68 kW on the first 50 cm  thermal cracking?
Mitigation strategy to be further investigated
M. Calviani, A. Ferrari, P. Sala
19th October 2012

17. M. Calviani, A. Ferrari, P. Sala
Update on the m fluence
Margins for the location of the ND
FLUKA implementation of the target “chase” design
First look at dose rate, absorbed dose and HEH fluence
First look at energy deposition
Ideas on potential neutrino target concepts
M. Calviani, A. Ferrari, P. Sala
19th October 2012

18. Potential neutrino target configuration
CNGS target design
Cooling by radiative emission and partially by convective exchange
Important: graphite at high temperature (~1000 ºC)
CNGS-like evolutionary design
Simpler construction and more diagnostics
Complete remote manipulation
Possibility to have an open He loop cooling – enhanced convection
No segmentation (only if mechanically needed)
Larger rod (&beam) radius  reduced off-axis issues and enhance LE p/K
M. Calviani, A. Ferrari, P. Sala
19th October 2012

19. M. Calviani, A. Ferrari, P. Sala
CNGS spare design
CNGS spare target ready for installation
©D. Grenier (EN/STI)
M. Calviani, A. Ferrari, P. Sala
19th October 2012

20. CNGS spare modified design
©D. Grenier (EN/STI)
New CNGS spare target – completely remotely handled
This solution potentially exclude the possibility to insert the target inside the horn!
M. Calviani, A. Ferrari, P. Sala
19th October 2012

21. M. Calviani, A. Ferrari, P. Sala
Conclusions
Margins for the muon range are not so reassuring
First preliminary shielding configuration of the target chase seems to indicate that the solution is viable
Collaboration with DGS/RP
Work with Polish student (EN/STI + DGS/RP) on-going
Already some preliminary ideas on neutrino target configuration
M. Calviani, A. Ferrari, P. Sala
19th October 2012