2. On-line pressure monitoring of Shape Memory Alloy - based vacuum set-ups under irradiation (TDC2)
EATM, 17th October 2017
F. Niccoli
Outline
Introduction
The concept and operation principle of a Shape Memory Alloy (SMA) connector
Possible applications of SMA connectors
Preliminary irradiation tests of SMA connectors
New irradiation tests in TDC2 (north area) : aim, description and tests requirements

3. Introduction: the need of remote operations at CERN
Radiation doses in some critical areas of HL-LHC, will increase by a factor of 16 in the next 20 years of operation.
Radiation doses in some critical areas of FCC are expected to be up to two order of magnitude higher than HL-LHC (Besana et al., 2016)
M.I. Besana, F. Cerutti, A. Ferrari, W. Riegler, and V. Vlachoudis. “Evaluation of the radiation field in the future circular collider detector”, CERN Report, 2016.
CMS CERN

4. Concept of SMA connectors for UHV applications
Current system
New concept
Typical ConFlat flange 
Proof of concept of SMA connectors for Ultra High Vacuum (UHV) chambers. 
Material properties:
NiTi based alloys
Magnetic permeability < 1.002
Thermal outgassing: < mbar.l.s-1.cm-2
Radiation hard ?? (tests ongoing)

5. Operation principle of a SMA connector
Mounting at room temperature
Tightening by heating above 100 °C
Leak Rate < mbar·l·s-1 at room temperature
Dismounting by cooling down to -40°C
T<As (40 °C)
T>Af (>100 °C)
T = RT
T<Mf (-40 °C)
pmax
pop
SMA ring
Tube
Mounting
Clamping
Operation
Dismounting
As: Austenite start temperature
Af: Austenite finish temperature
Ms: Martensite start temperature
Mf: Martensite finish temperature

6. Advantages and potential applications
A compact, leak tight and easily mountable\dismountable connection system
Possibility of remote controlling
Possibility to use in high demanding areas (e.g. collimator areas, machine/detector interface)
Possibility to use in limited access spaces
Possibility to connect dissimilar materials
HL-LHC Machine Detector interface
CLIC main linac
CLIC module installed in CLEX

7. Radiation tests at CHARM
Preliminary Irradiation of SMA-based prototype vacuum chambers
Radiation tests at CHARM
Simulations by FLUKA
Dose (Gy/POT) maps in (a) the SMA-based chambers
Dose map in the IT area right side of ATLAS for HL-LHC operation
Sample placement at CHARM facility
The predicted integrated dose absorbed by a SMA connector after a year of possible operation (HL-LHC) in proximity of the inner triplets areas is about 100 kGy;
Integrated dose absorbed by SMA ring after exposure at CHARM: ≈ 120 kGy

8. Prototype SMA-based vacuum chambers for irradiation tests
Preliminary Irradiation of SMA-based prototype vacuum chambers
Particles spectra
Prototype SMA-based vacuum chambers for irradiation tests
Particles Lethargy Energy with Cu target in correspondence of the SMA position.

9. Preliminary tests @CHARM: Post irradiation results
Functional behavior not significantly affected by the irradiation (up to 120kGy).
Leak tests
Dismounting
Leak Rate < mbar l s-1
T<-40 °C (NiTi)

10. Preliminary irradiation tests in TDC2 (TCSC.220436) :
Off-line pressure monitoring of a SMA-based vacuum set-up
Expected dose ≈ 200 kGy/year
Set-up placed/removed by Robot intervention (EN-STI)
Vacuum Set-up (Vacuum chambers + pre-activated NEG strips, Penning gauge, SVT gauge, SMA connector with RPL dosimeters)

11. Preliminary irradiation tests in TDC2 (TCSC.220436) :
Off-line pressure monitoring of a SMA-based vacuum set-up
Preliminary TDC2 long term irradiation test results
Date
Action
Pressure
Penning
SVT
Dose (RPLs)
Placement in TDC2
~3E-10 mbar
~2E-10 mbar
1st control measurement
~3E-8 mbar
~2.5E-8 mbar
~24
kGy
2 nd control measurement
High pressure
(higher than E-4 mbar)
High pressure interlock
~52
Measurements performed at a distance from high radiation area (in TA801)
Equivalent dose rate < 5 mSv/h
Cables connection
with fast intervention ! (1 minute )

12. Preliminary irradiation tests in TDC2 (TCSC.220436) :
Off-line pressure monitoring of a SMA-based vacuum set-up
Pressure increase compatible with Argon outgassing
(Noble gases not pumped by the NEG)
Preliminary TDC2 long term irradiation test results
Date
Action
Pressure
Penning
SVT
Dose (RPLs)
Placement in TDC2
~3E-10 mbar
~2E-10 mbar
1st control measurement
~3E-8 mbar
~2.5E-8 mbar
~24
kGy
2 nd control measurement
High pressure
(higher than E-4mbar)
High pressure interlock
~52
Cables connection
with fast intervention ! (1 minute )
Measurements performed at a distance from high radiation area (in TA801)
Equivalent dose rate < 5 mSv/h
Pressure increase due to possible NEG saturation!
Need of a pumping system with high pumping speed and large capacity for future tests!

13. New irradiation tests on SMA Set-ups in TDC2 (TCSC.220436):
On-line pressure monitoring and continuous pumping
Installation foreseen during YETS 2017/2018
Duration of the test ≈ 1 year (until the beginning of LS2)
Expected absorbed dose: ≈200 kGy/y
4 set-ups
Passive Penning
(on-line measurements)
Passive Pirani
(on-line measurements)
Strain gauges + RPL dosimeters
(Off-line measurement far from the radiation area)
≈ 300 mm
Connection interface box for robot operation (cable plugging/unplugging)
NexTorr pump
(Ion pump + NEG)
SMA ring
≈ 500 mm
≈ 200 mm
Large pumping
speed and capacity
(No noble gases and CH4)
Continuous pumping (also Ar, CH4)

14. New irradiation tests on SMA Set-ups in TDC2 (TCSC.220436):
On-line pressure monitoring and continuous pumping
Cable length 200 m+ 180m
Control
(Existing rack in BA80)
Irradiation position (close to the nearest BLM, under TCS C)

15. New irradiation tests on SMA Set-ups in TDC2 (TCSC.220436):
On-line pressure monitoring and continuous pumping
Requirements 1
Cables DIC to be prepared + 2x patch panels
Pennings
4 X TFAR3 (radiation tolerant)
HV LEMO Male
~200m
RAL003 (Patch panel location) -> TCS C
4 X TFA3
~180m
RAL003 -> Surface (BA80)
Pirani
4 X NGR4 (radiation tolerant)
Burndy 4 Male
RAL003 -> TCS C
4 X NG4
NexTorr
4 X SVAR3 (radiation tolerant)
HV Fischer
4 X SVA3
Requirements
for 4 set-ups!
Set ups will be equipped with interface box for robot operation (connection/disconnection)

16. New irradiation tests on SMA Set-ups in TDC2 (TCSC.220436):
On-line pressure monitoring and continuous pumping
Requirements 2
Controls Hardware to be placed in an existing rack in BA80
Pennings & Pirani
2 xTPG300
4 x Pirani/Penning E-11mbar cards
2x Profibus card
NexTorr
1 X 4UHV Agilent controller/power supply [2.6kCHF]
(Additional pressure measurement)
PLC
Existing Master PLC (no cost)
Controls Software (update VAC DB, PLC, SCADA)
SCADA (online monitoring and DB logging)
Penning & Pirani & Agilent ctrl
existing framework
Requirements
for 4 set-ups!

17. New irradiation tests on SMA Set-ups in TDC2 (TCSC.220436):
On-line pressure monitoring and continuous pumping
Passive Pirani
Other points
Strain Gauges measurements (connection to the DAQ and readout by means of proper fast connectors/interfaces) will be performed ≈ 3 times in a year. The set-ups have to be transported by robots to the access doors of TA801.
Set-ups handling/transportation for strain gauges and/or dosimetry (RPLs) measurements have to be discussed with RP and EN/STI. Interventions have to be planned in advance.
EN/STI (Mario Di Castro) needs to be consulted for the interface box design and training of the robots (cables connection/disconnection)
Passive Penning
Strain gauges + RPL dosimeters
(Off-line measurement far from the radiation area)
Connection interface box for robot operation (cable plugging/unplugging)
Nextorr Pump
SMA ring

18. Thanks for your attention!
Special thanks for suggestions/inputs from:
Pawel Krakowski (TE-VSC-ICM),
Cedric Garion (TE-VSC-DLM),
Paolo Chiggiato (TE-VSC)
Niccoli F., Garion C., Maletta C., Sgambitterra E., Furgiuele F. and Chiggiato P., “Beam-pipe coupling in particle accelerators by shape memory alloy rings”, Materials and Design, 2017, Vol. 114, pp. 603–611.
Niccoli F., Garion C., Maletta C., and Chiggiato P., “Shape memory alloy-based pipe couplers for ultra-high vacuum applications in particle accelerators: design and experimental assessment”, Journal of Vacuum Science and Technology A, 2017, Vol. 35 (3).
REFERENCES (only about NiTiNb connectors):