EuCARD WP 7 – High Field Magnets Task 7.2 – Support Study Status report EuCARD WP 7 – High Field Magnets Task 2 – Support studies Task 7.2 – Support Study Status report EuCARD WP7 Collaboration Meeting – INFN-LASA Milano Maciej Chorowski, Jaroslaw Polinski, Piotr Bogdan Faculty of Mechanical and Power Engineering

2 Outline Sample irradiation Cryostat for electrical test Mechanical tests Thermal test at PWR Task 7.2 planning

3 Material burning during the irradiation

4 Pt 1000 sensor 1st possible reason: Lack of LN2 during irradiation? The samples holder is equipped with Pt1000 T sensor. In case of temperature exceed 80K the accelerator control system stops the accelerator

5 Material burning during the irradiation 2nd possible reason: Heat deposited in the irradiated sample creates LN2 vapor bubbles around the heated area. Due of that the cooling capacity of the coolant drastically decrease and temperature of the sample increase over the material melting or flash point Decision: reduction of the dose rate by 1/2 and see if the material is still burning for 50MGy of total dose Beam LN2 LN2 vapors Irradiated sample

6 Methods of the dose rate reduction 4s4s 6,67 ms N electrons/  s 4s4s 13,33 ms 2s2s 6,67 ms N electrons/  s 4s4s 6,67 ms 1/2N electrons/  s Original beam scheme Decrease of impulse frequency Decrease of impulse time Decrease of impulse intensity

7 Material burning during the irradiation Mix 71 Mix 237 LARP Lonza CE 1st package – irradiated with 16 kGy/min 2nd package – irradiated with 10.8 kGy/min

8 Irradiation plan prediction (based on the present irradiation procedure knowledge) End of EuCARD

9 Toward to complete the irradiation certification program in the EuCARD time frame Determination/confirmation of the maximum dose rate which not cause the sample burning Change of thermal properties test method –thermal conductivity and heat capacity in 4-300K temperature range can be determined on very small material sample by Institute of Low Temperature and Structure Research (ILTSR) in Wroclaw –the samples for this tests can be extracted from the electrical or mechanical samples after them tests –preparation of separated samples for the thermal tests, irradiated with 1 spot, can be considered Change of number of the irradiation spots on the mechanical samples from 4 to 1

10 Patterns for thermal samples - 4 spots, d= 17.5 mm

11 Preliminary mechanical tests Mech. sample preparation

12 Preliminary mechanical tests Mech. tests – irradiated samples BurnedNormal (Total dose: 0.5 – 0.7 MGy)

13 Outline Sample irradiation Cryostat for electrical test Mechanical tests Thermal test at PWR Task 7.2 planning

14 Electrical certification test cryostat Voltage source – up to 60kV

15 Electrical certification test cryostat stsus Cryostat was delivered at the end of August 2012 Instrumentation - ongoing Commissioning, determination of the test procedure and first tests – mid. of Oct. 2012

16 Outline Sample irradiation Cryostat for electrical test Mechanical tests Thermal test at PWR Task 7.2 planning

17 Mechanical tests status Update of existing mechanical set-up with elements allow measurements in LN2 is undergoing in collaboration with PWR MechLab The possibility and quality of the mechanical sample cut- off with WaterJet technique will be tested next weeks The PWR MechLab has possibility to test the sample with Fourier Transform Infrared Spectroscopy (FTIS) and with Thermal Gravimetric Analysis (TGA), what can provide more information about the samples destruction origin (thermal/radiation)

18 Outline Sample irradiation Cryostat for electrical test Mechanical tests Thermal test at PWR Task 7.2 planning

19 Thermal tests – test parameters Material: unirradiated Mix 71 (NED insulation) Thicknesses:  m,  m,  m,  m Bath temperature levels: 1.5K, 1.55K, 1.6K. 1.7K, 1.8K, 1.9K, 2.0K, 2.1K Dissipated heat range: 0÷125mW/sample = 0÷12 W/m 2 Heat step: 2mW Heat step time: min. 4 min Temperature increase range considered in post-test analysis: 10÷35mK Bath temperature stabilization: ±0.25mK

20 Thermal tests – set-up view

21 Thermal tests – test results Thermal conductivity

22 Thermal tests – test results Kapitza resistance

23 Outline Sample irradiation Cryostat for electrical test Mechanical tests Thermal test at PWR Task 7.2 planning

24 WP7.2 Plan

25 Summary The sample burning during irradiation has been found Decrease of the irradiation dose rate from 16.0 to 10.8 kGy/min avoided this problem, nevertheless the max allowed dose rate need to be found/confirmed To keep the EuCARD time scale the modification in the thermal property certification test as well as in the mechanical and the thermal sample irradiation pattern is proposed Cryostat for electrical certification tests has been delivered and is currently under instrumentation on PWr. First certification tests are foreseen for mid of Oct. Preparation of the mechanical certification test in the LN2 conditions is ongoing Thermal conductivity and Kapitza resistance values of Mix 71 (NED) insulation has been confirmed on the PWr HEII cryostat experiment