WP5
Elliptical Cavities Cryomodules
Pierre BOSLAND, CEA Saclay
External WP5 leader
Christine Darve,
ESS deputy WP leader
TAC11 1rst April 2015
The elliptical cavity cryomodules in
the ESS linac
Klystron gallery
MEDIUM-β
HIGH-β
0.67
0.86
# CM
9
21
Cav. /CM
4
4
# Cav.
36
84
6.584
6.584
77
179
β
CM L [m]
Sector L [m]
1st April 2015
Proton Beam
Elliptical cavities Cryomodules
Medium-b and high-b
ESS TAC11
2
Framework of the cryomodules
development and production
1. Two prototype cryomodules:
2. medium beta:
M-ECCTD
3. High beta:
H-ECCTD
<= FR-SW agreement
<= CEA FR In Kind Contribution
2. Production of cavities of the series with RF tests:
3. medium beta cavities
<= LASA - IT In Kind Contribution
4. High beta cavities
<= STFC - UK In Kind Contribution
3. Production of all other components:
<= CEA FR In Kind Contribution
(including coupler production with RF power processing)
4. Cryomodule assembling :
<= CEA FR In Kind Contribution
5. RF power tests of the cryomodules
<= ESS Lund
1st April 2015
TAC11
3
FR in kind activities starting at
Saclay (“early in kind”)
ESS - AB
ACCSYS
ACCSYS
ACCSYS
ICS
ICS
Technique :
Technical
Board
ESS - AB
Management :
Coordination C.
Collaboration C.
In Kind Review C.
WP 3
WP 5
WP 7
WP 6
WP 10
Responsables
IRFU reorganization
2015:
Cellule Qualité on the 1rst of June
ESS - IRFU
A Bruniquel
C. Cloué
Florence O.Sécurité
Ardellier:
Kuster
Pierre Bosland :
WP
Tests IPHI
B. Pottin
WP
Bunker 352 MHz
JP. Charrier
WP ECCTD
F. Peauger
M-ECCTD
CdP: P. Bosland
Adjoint: A. Daël
WP
Cryomodules
de série
P. Bosland/XXX
IKC
H-ECCTD
ACCSYS WP5
1st April 2015
Scientifiques
G. Devanz
D. Uriot
O. Piquet
Projet ESS / IRFU
Project Office
planning: X. Hanus
ressources: L. Lecourt
secrétaire: XX
Project Manager
Scientific Director
WP RFQ
B. Pottin
WP
Diagnostics
F. Sénée
WP
Contrôle
Commande
F. Gougnaud
WP
Test
injecteur
B. Pottin
ACCSYS WP7
ICS WP 6 /
10
ACCSYS WP3
Design RFQ
IKC
RFQ
ACCSYS WP3
TAC11
4
Overview of the design of the
cryomodules and components
First results on prototype high
beta cavities
On behalf of the CEA Saclay, IPN Orsay team and ESS team:
C. Arcambal, G. Devanz, P. Bosland, E. Cenni, P. Hardy, F. Leseigneur, J.
Plouin, G. Ferrand, F. Eozenou, C. Servouin,
D. Roudier, L. Maurice, X. Hanus, C. Madec, JP. Poupeau, N. Bazin, N.
Berton, V. Hennion, JP. Charrier, O. Piquet,
P. Carbonnier, B. Renard, P. Sahuquet, A. Hamdi, CEA Saclay
G. Olivier, JP. Thermeau, IPN Orsay
C. Darve, N. Elias, G. Costanza ESS
1st April 2015
TAC11
5
Cryomodule design and prototyping
Fr-SW agreement
Collaboration IPNO – IRFU
IPNO in charge of the cryostat – design and fabrication
Vacuum vessel
Space frame – cavity supports
Thermal screen
Superinsulation
Internal cryogenic pipes
Instrumentation
G. Olivier
IRFU in charge of the “cavity package”, the cryomodule assembly and
RF power tests:
Cavities + helium tank
Power coupler
Piezo tuner
Magnetic shield
Tooling: field flatness, cavity preparation,
assembling, …
Cryomodule assembly
Tests stand for cryogenic and RF power tests
Tests of the ECCTD cryomodule
cryomodule
Medium beta prototype cryomodule M-ECCTD
Generic design for
medium & high beta
cryomodules
The level-4 requirements for the medium and high beta cryomodules are listed in the DOORS
management system (Dynamic Object-Oriented Requirements System).
Conformance of the design with these requirements has been presented at a-TAC (October 2013).
1st April 2015
TAC11
6
Cryomodule design
G. Olivier
 Similar to CEBAF/SNS cryomodule concept with 4 cavities per cryomodule
 Common design for medium (6 cells) and high beta (5 cells) cavities
Jumper connection
Heat exchanger
Spaceframe
support
Magnetic
shielding
Regulation He valve
Vacuum
valve
Thermal Alignement fiducial
shielding
Diphasic He pipe
Proton Beam
Cold to warm
transition
1st April 2015
Intercavities
belows
Power coupler
TAC11
Cavity with
Helium tank
7
Cavities design
Magnetic
shielding
Tank (Ti)
High beta (0,86):
5 cells
Length 1316,91mm
Cold tuning system
Medium beta (0,67):
6 cells
Length 1259,40mm
Medium
High
94
120
1.22
1.8
0.54
1.2
2.36
2.2
Bpk/Eacc (mT/(MV/m))
4.79
4.3
Maximum. r/Q (W)
394
477
0.705
0.92
196.63
241
Iris diameter (mm)
Cell to cell coupling k (%)
p and 5p/6 (or 4p/5) mode
separation (MHz)
Epk/Eacc
Optimum b
11 DEC 2014
G (W)
Geometrical beta
Frequency (MHz)
Operating temperature (K)
Maximum surface field in
operation (MV/m)
Nominal Accelerating gradient
(MV/m)
Nominal Accelerating Voltage
57,5 mm (MV)
Q0 at nominal gradient
Cavity dynamic heat load (W)
Qext
Medium
High
0.67
0.86
704.42
2
44
44
16.7
19.9
14,3
18,2
> 5e9
4,9
7.5 105
6,5
7.6 105
 Challenging accelerating gradients and Q0
 No HOM couplers
• HOM frequencies and internal cavity shape
must be carefully controlled
G. Devanz, J. Plouin,
G. Constanza
Tests of the 2 prototype cavities in
vertical cryostat
P01 - E. ZANON
P02 - RI
Protypes with HOM ports for
RF measurement
Both prototype cavities met the ESS requirements after the first test: very encouraging results!
Slight degradation of performances after thermal treatment for hydrogen removing (pollution)
1st April 2015
ESS TAC11
9
Tests of the 2 prototype cavities in
vertical cryostat
EFFECT of BCP on the frequency
Tuning sensitivity
DF/Dz (kHz/mm)
ESS067
ESS086
Calculated
214.8
197
Measured
190
Stiffness (kN/mm)
ESS067
ESS086
1.286
2.59 (3.6 mm thick)
3.3 (4.5 mm thick)
Calculated
Measured
• Measured LFD coefficient: KL = -7.65 Hz/(MV/m)²
• Close to the calculated value of -8.9 Hz/(MV/m)² in free
ends conditions
3
Frequency shift DF due to
cooldown and vacuum (kHz)
300K to 4.2 K
Calculated
Measured
Ɛr to Ɛo
1st April 2015
Measured
TAC11
ESS086
+1.0067
+1.00138
+0,211
+0.211
300K to 4.2K
~ +1.08
Ɛr to Ɛo
+0.015
Frequency shift DF due to
cooldown and pressure (kHz)
Calculated
ESS067
ESS067
ESS086
4.2 K to 2 K
~ + 0.207
10
Dangerous Higher Order Mode
close to 1408.8 MHz
Both high beta prototype cavities are not conform with the ESS HOM Requirement
Reminder: « All higher order modes (HOMs) shall be at least 5 MHz away from integer multiples of the
beam-bunching frequency (352.21 MHz) for any HOMs whose resonant frequencies are below the cut-off
frequency of the beam-pipe.”
Slater coefficient analysis which
represents frequency sensitivity to
volume changes:
704 MHz
1421,32 MHz
 3D measurements of the cavity shape have been performed
 Shape reconstructed in the simulation software HFSS
Calculated with
Calculated with
Measured on
measured
measured
ESS086-P02
shape (HFSS)
shape (HFSS)
Design
(at 300K)
Measured on
ESS086-P01
1418.178
1402.254
1403.8
1407.848
1418.674
1404.666
1406.8
1408.258
 On P01 cavity (from ZANON), a strong internal shape deviation in
this dome region (more than 1 mm instead of 0.3 mm) explains
very well the frequency decrease of the two dangerous HOM
 Study under progress on P02 cavity (from RI)
 Cells reshaping has to be implemented in the fabrication process of future cavities
1st April 2015
TAC11
11
Titanium Helium tank of ESS086-P01
welded (ZANON)
 DF = +9 kHz only due to tank welding
 Pressure and leak test done successfully
 Delivery at CEA in 1 or 2 weeks for CV test only (not compatible with the cryomodule)
1st April 2015
TAC11
12
Start of production of the ½ cell for 6
medium beta cavities
 6 cavities ordered at ZANON, 4 of them will be integrated into the M-ECCTD cryomodule
 Niobium received and sent to ZANON
 Deep drawing tests on copper plates
 Preparation of RF measurement equipements for half cells and dumbbells
1st April 2015
TAC11
13
Power coupler procurement in
progress
→ For the prototype cryomodules, the coupler
procurement is divided into three parts
8 x RF window+antenna
→ TOSHIBA
1st April 2015
6 x double wall external
conductor
→ 2 companies in tender
ESS TAC11
6 x Door Knob
→ Spec. in progress
14
Power coupler conditioning set-up
 Assembled in clean room
 Tested with a 1.1 MW klystron and
variable short circuit / matched load
1st April 2015
ESS TAC11
15
Tooling design finalized for the assembly
of the cavity string clean room
 Coupler / cavity assembly vertically
 Tooling compatible for both cavity types
 Adjustment of the coupler position
relative to the cavity flange
 Cart in two parts with clean room rails
 Each cavity is supported by two posts and beam valves on one post
 Cavity string put under vacuum for the first prototype
1st April 2015
ESS TAC11
N. Bazin, C. Madec, JP Poupeau,
Ph. Hardy, F. Leseigneur
16
Test stand
new cryolines installation
Test bunker
(cryomodule will be
installed inside)
Pumping line
DN250
He return line
1st April 2015
Dewar LHe
2000 L
Cryogenic line
He Supply, 50 m long
(from CERN)
ESS TAC11
JP Charrier,
P. Sahuquet,
B. Renard
17
704 MHZ - 1 MW RF power source
upgrade
A. Hamdi, M. Desmons,
F. Ballester
increase the pulse length from 2 ms to 3.5 ms
HVPS
C
R2
C’ R’
C//C’=10µF
(Energie=60,5kJ)
R’//R2=25 Ohms
(tenue: 84kJ)
Load
 Additional capacitors and resistances in
parrallel on the HV modulator
1st April 2015
 Conditionning of the CPI 1.15 MW klystron up to
the ESS duty cycle was done with success
ESS TAC11
18
18
Compliance with European
PED 97/23/EC
Cryo pipes designed to reduce the overpressure in case
of beam vacuum failure
TUV Nord analysis report:
The elliptical cryomodules are
classified according to PED article 3.3
2 F=100 bursting disks at each
extremity
continuous diphasic pipe
F=100 with large
curvatures
•
•
•
Volumes of the helium circuits and vessels < 50 l
1,431 bars< Working pressure
Ps = 1,9 bars
1st April 2015
TAC11
19
Overall WP5 planning
1st April 2015
TAC11
20
WP5 planning compliant with RFI dates
Task name
PROTOTYPES ECCTD
duration
start date
end date
34 ms
Jeu 01/01/15
Lun 13/11/17
27 ms
Jeu 01/01/15
Mar 11/04/17
Tests
4 ms
Lun 10/10/16
Mer 08/02/17
Mid-test flag
0 ms
Ven 09/12/16
Ven 09/12/16
PRR review decision
0 ms
Ven 23/12/16
Ven 23/12/16
End of the tests - Disassembly
2 ms
Jeu 09/02/17
Mar 11/04/17
28 ms
Lun 06/07/15
Lun 13/11/17
Tests
2 ms
Mer 13/09/17
Lun 13/11/17
Mid-test flag
0 ms
Ven 13/10/17
Ven 13/10/17
PRR review decision
0 ms
Ven 13/10/17
Ven 13/10/17
49 ms
Ven 23/12/16
Mer 10/02/21
21 ms
Ven 23/12/16
Mar 02/10/18
12 ms
Jeu 28/09/17
Mar 02/10/18
39 ms
Ven 27/10/17
Mer 10/02/21
30 ms
Jeu 02/08/18
Mer 10/02/21
M-ECCTD
H-ECCTD
CAVITIES
Medium beta production (INFN) (36)
Cavity delivery (3 cav/m.)
High beta production (STFC) (84)
Cavity delivery (3 cav/m.)
COUPLERS
64 ms
Lun 01/06/15
Mer 21/10/20
Conditioning stand
24 ms
Lun 01/06/15
Mer 07/06/17
Manufacturing & RF processing (36+84)
51 ms
Lun 01/06/15
Mar 17/09/19
Pre-serial manufacturing (4)
13 ms
Ven 09/12/16
Ven 12/01/18
RF conditionning Pre-serial (2 pairs)
6 ms
Jeu 08/06/17
Ven 08/12/17
Restart serial prod delay
4 ms
Ven 08/09/17
Mar 09/01/18
manufacturing MBC 1-36 (6cpl./m.)
6 ms
Mer 10/01/18
Jeu 12/07/18
RF conditionning MBC (4 cpl./m.)
10 ms
Mar 13/03/18
Lun 14/01/19
manufacturing HPC 1-84 (6cpl./m.)
14 ms
Ven 13/07/18
Mar 17/09/19
RF conditionning HBC 1-44 (4 cpl./m.)
11 ms
Mar 15/01/19
Mer 18/12/19
RF conditionning HBC 45-84 (4 cpl./m.)
10 ms
Jeu 19/12/19
Mer 21/10/20
CRYOMODULES
2015
2016
2017
2018
2019
Hb cavities delivery
Couplers procurement assembly and tests
Conditionning stand
Manufacturing & RF processing
Mb couplers processing
Hb couplers processing
Hb couplers processing
Cryomodules procurement assembly and tests
CM manufacturing
MBL cryomodules
MBL assembly
Ven 14/01/22
54 ms
Mar 01/09/15
Jeu 19/03/20
MBL Modules assembly
16 ms
Ven 29/12/17
Lun 06/05/19
14 ms
Ven 29/12/17
Mar 05/03/19
n°1
4 ms
Ven 29/12/17
Mar 01/05/18
n°2-3
4 ms
Mer 02/05/18
Ven 31/08/18
n°4-9
6 ms
Lun 03/09/18
Mar 05/03/19
6
11 ms
Ven 01/06/18
Lun 06/05/19
MBL tests
n°1
2 ms
Ven 01/06/18
Mer 01/08/18
n°2-3
3 ms
Jeu 02/08/18
Jeu 01/11/18
n°4-9
6 ms
Ven 02/11/18
Lun 06/05/19
HBL Modules
33 ms
Ven 05/04/19
Ven 14/01/22
Assembly
31 ms
Ven 05/04/19
Lun 15/11/21
n°1-11
16 ms
Ven 05/04/19
Lun 10/08/20
n°12-21
15 ms
Mar 11/08/20
Lun 15/11/21
31 ms
Jeu 06/06/19
Ven 14/01/22
16 ms
Jeu 06/06/19
Ven 09/10/20
15 ms
Lun 12/10/20
Ven 14/01/22
RF
st power tests at Lund
1 n°1-11
April 2015
n°12-21
2022
P. Michelato Mb cavities
P. McIntosh Hb cavities
Hb cavities production
75,64 ms Mar 01/09/15
RF power tests at Lund
2021
Cavities production Mb & Hb
Mb cavities prod
Mb delivery
Components manufacturing
Assembly
2020
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
1
2
1
2
6
HBL cryomodules
Assembly 21 HBL
11 HBL
10 HBL
TAC11
21
tests 21 HBL
11 HBL
11 HBL
Milestones for tendering
• Cavity test in vertical cryostat (Nominal performances Eacc & Qo)
 Required prior tendering for niobium production for series
 Test of the 1st medium beta cavity scheduled on 01 October 2015
 OK for High beta cavities: 2 prototypes already tested
• RF power tests at 2K of the ECCTD + Critical Design Review
 Required prior tendering cavities , couplers and all components of the
cryostats
 M-ECCTD: CDR on the 23/12/2016 => Mb cavities + couplers + cryostats
 H-ECCTD: CDR on the 13/10/2017 => Hb cavities only needed
CDR (Critical Design Review) ~ Production Readiness Review
1st April 2015
TAC11
22
Planning main assumptions made to
reach the goal of the RFI dates for MBL
1.
Success oriented planning to match the ESS schedule: no margin, assumed no non-conformity for all cavities,
couplers and components;
2.
The first results of the M-ECCTD are successful and the series production of Mb cavities, power-couplers and
cryostat components are launched 2 weeks later (CDR). This implies that the tendering is finalized, the contracts are
awarded at the time of CDR and the series fabrication starts;
3.
Rate of cavities production and delivery at Saclay after RF test: 3/month (Mb & Hb cavities);
4.
Delivery of the 1st serial cavity tested and qualified 6 months after the start of the cavity production; (required
previous preparation by LASA and STFC of the industry and labs for cavity production, cavity treatments and cavity
tests)
6.
Rate of the coupler RF processing = 4 couplers/month will be confirmed end of 2015 (ECCTD couplers);
7.
Rate of the cryomodules assembly:
•
•
•
1st cryomodule:
2nd & 3rd :
4th to 9th:
4 months
2 month / CM
1 month/CM
8.
The RF test stand at Lund shall be fully operational for the 1st cryomodule (Q1 2018) and the testing rates are:
•
1st cryomodule: 2 months
•
2nd & 3rd :
1,5 month / CM
th
th
•
4 to 9 :
1 month/CM
9.
The cryomodule assembly in Saclay by the new industrial team is qualified after the test of the 1st cryomodule.
10. The 2nd and 3rd cryomodules need to be assembled before the end of the tests of the 1st cryomodule.
1st April 2015
TAC11
23
Overall WP5 planning
Task name
PROTOTYPES ECCTD
duration
start date
end date
34 ms
Jeu 01/01/15
Lun 13/11/17
27 ms
Jeu 01/01/15
Mar 11/04/17
Tests
4 ms
Lun 10/10/16
Mer 08/02/17
Mid-test flag
0 ms
Ven 09/12/16
Ven 09/12/16
PRR review decision
0 ms
Ven 23/12/16
Ven 23/12/16
End of the tests - Disassembly
2 ms
Jeu 09/02/17
Mar 11/04/17
M-ECCTD
H-ECCTD
28 ms
Lun 06/07/15
Lun 13/11/17
Tests
2 ms
Mer 13/09/17
Lun 13/11/17
Mid-test flag
0 ms
Ven 13/10/17
Ven 13/10/17
PRR review decision
0 ms
Ven 13/10/17
Ven 13/10/17
49 ms
Ven 23/12/16
Mer 10/02/21
21 ms
Ven 23/12/16
Mar 02/10/18
12 ms
Jeu 28/09/17
Mar 02/10/18
39 ms
Ven 27/10/17
Mer 10/02/21
30 ms
Jeu 02/08/18
Mer 10/02/21
CAVITIES
Medium beta production (INFN) (36)
Cavity delivery (3 cav/m.)
High beta production (STFC) (84)
Cavity delivery (3 cav/m.)
COUPLERS
64 ms
Lun 01/06/15
Mer 21/10/20
Conditioning stand
24 ms
Lun 01/06/15
Mer 07/06/17
Manufacturing & RF processing (36+84)
51 ms
Lun 01/06/15
Mar 17/09/19
Pre-serial manufacturing (4)
13 ms
Ven 09/12/16
Ven 12/01/18
RF conditionning Pre-serial (2 pairs)
6 ms
Jeu 08/06/17
Ven 08/12/17
Restart serial prod delay
4 ms
Ven 08/09/17
Mar 09/01/18
manufacturing MBC 1-36 (6cpl./m.)
6 ms
Mer 10/01/18
Jeu 12/07/18
RF conditionning MBC (4 cpl./m.)
10 ms
Mar 13/03/18
Lun 14/01/19
manufacturing HPC 1-84 (6cpl./m.)
14 ms
Ven 13/07/18
Mar 17/09/19
RF conditionning HBC 1-44 (4 cpl./m.)
11 ms
Mar 15/01/19
Mer 18/12/19
RF conditionning HBC 45-84 (4 cpl./m.)
10 ms
Jeu 19/12/19
Mer 21/10/20
CRYOMODULES
2015
2016
2017
2018
2019
Cavities production Mb & Hb
Mb cavities prod
1) Mb cavities contract awarded
Mb delivery
1) Hb cavities
contract
awarded
Hb cavities
production
Hb cavities delivery
Couplers procurement assembly and tests
Conditionning stand
RF power source ready for coupler
Mb couplers processing
Hb couplers processing
Hb couplers processing
Cryomodules procurement assembly and tests
Cryomodule
components contract awarded
CM manufacturing
MBL cryomodules
MBL assembly
Ven 14/01/22
Mar 01/09/15
Jeu 19/03/20
MBL Modules assembly
16 ms
Ven 29/12/17
Lun 06/05/19
14 ms
Ven 29/12/17
Mar 05/03/19
n°1
4 ms
Ven 29/12/17
Mar 01/05/18
n°2-3
4 ms
Mer 02/05/18
Ven 31/08/18
n°4-9
6 ms
Lun 03/09/18
Mar 05/03/19
6
11 ms
Ven 01/06/18
Lun 06/05/19
MBL tests
n°1
2 ms
Ven 01/06/18
Mer 01/08/18
n°2-3
3 ms
Jeu 02/08/18
Jeu 01/11/18
n°4-9
6 ms
Ven 02/11/18
Lun 06/05/19
HBL Modules
33 ms
Ven 05/04/19
Ven 14/01/22
Assembly
31 ms
Ven 05/04/19
Lun 15/11/21
n°1-11
16 ms
Ven 05/04/19
Lun 10/08/20
n°12-21
15 ms
Mar 11/08/20
Lun 15/11/21
31 ms
Jeu 06/06/19
Ven 14/01/22
16 ms
Jeu 06/06/19
Ven 09/10/20
15 ms
Lun 12/10/20
Ven 14/01/22
1 n°1-11
April 2015
n°12-21
processing
& RF
processing
2)Manufacturing
Power couplers
contract
awarded
54 ms
RF
st power tests at Lund
2022
H-ECCTD CDR review decision
75,64 ms Mar 01/09/15
RF power tests at Lund
2021
M-ECCTD CDR review decision
Components manufacturing
Assembly
2020
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
1
2
1
2
Planning Ready For Installation OK with
ESS schedule:
03/09/18 => 02/05/19
1CM/month
6
HBL cryomodules
Planning Ready For Installation OK with ESS
schedule:
Q1 + Q2 2021: installation of HBL n° 1 to 11
TAC11
Q1 + Q2 2022: Installation of HBL n° 12 to 21
Assembly 21 HBL
11 HBL
10 HBL
24
tests 21 HBL
11 HBL
11 HBL
1st April 2015
TAC11
25
Conclusion
•
The design of the elliptical cavities and cryomodules complies with the ESS
requirements.
•
The prototype cryomodules M-ECCTD and H-ECCTD will validate the design.
•
The preliminary planning for the design/prototyping and for the production of the
elliptical cryomodules has been proposed in compliance with the RFI dates.
•
This planning is success oriented with major risks identified
•
The coordination between the In-Kind partners has to be quickly placed to start the
work as soon as possible:
Coordination between CEA, CNRS, INFN, STFC and ESS
We have to established a "partnership of ESS with INFN and STFC, which will permit to
make use of the best European competences in the field of SRF".
1st April 2015
ESS TAC11
26
Open discussion
1.
2.
3.
4.
5.
6.
Requirements and interfaces
Schedule and Reviews list
Integrated production plan
Nb procurement
Industrialization and lessons-learned
Acceptance criteria (production, test,
conditioning)
7. Data management and filing of NC
8. Risk assessment (TD, beam impact)
9. Transportation
1st April 2015
TAC11
27