SNO+ Summer Report

SNO+ Cover Gas Bag Fabrication and System Instrumentation, Scintillator Plant Construction and UI Involvement

September 8, 2013

By Jennifer MauelQueen's University Physics Department

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Table of ContentsSection 1: The Cover Gas System

Introduction.................................................................................................................................4

1.1 Cover Gas Bags.......................................................................................................................4

Bag Pressure Tests...........................................................................................................4

Bag Fabrication................................................................................................................7

Bag Boxes.........................................................................................................................9

1.2 Instrumentation.....................................................................................................................9

Laser Distance Sensors....................................................................................................9

Calibration............................................................................................................9

` Reproducibility/Stability Test.............................................................................10

Webcams.......................................................................................................................11

Oxygen Monitors...........................................................................................................11

NTRON Microx Inline ZR....................................................................................12

Calibration, Sensitivity and LAB Compatibility Tests.............................13

Radon Emanation..................................................................................14

Presens OIM Pst6-D12/L20................................................................................15

Vacuum Pump................................................................................................................15

Valves.............................................................................................................................16

Section 2: Scintillator Plant Construction..............................................................................................17

2.1 Leak-checking......................................................................................................................17

2.2 Scintillator Plant Construction.............................................................................................29

Section 3: Lower Universal Interface Leak-Checking............................................................................32

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List of FiguresFigure 1: Bag fitting connects to u-tube manometer and compressed air supply. Laser distance sensor sits underneath the bag belly.......................................................................................................5Figure 2: Rotary hand-held heat sealer...................................................................................................7Figure 3: Helium leak-checker with sniffer probe...................................................................................7Figure 4: Pre-rubberizing in the negative pressure room.…...................................................................8Figure 5: Post-rubberizing in the negative pressure room......................................................................8Figure 6: Cover gas bag in one of the custom-designed boxes...............................................................9Figure 7 Laser distance sensor circuit...................................................................................................10Figure 8: Laser distance sensor calibration set-up................................................................................10Figure 9: Potential webcams for monitoring the cover gas bags..........................................................11Figure 10: Typical in-line set up of NTRON oxygen analyser.................................................................12Figure 11: Leak-testing the zirconia probe mounting and ¼” cross.....................................................13Figure 12: Calibration, sensitivity testing and LAB compatibility testing..............................................14Figure 13: The Pfeiffer Vacuum MVP 006 diaphragm pump................................................................15Figure 14: Graph of pumping speed vs. pressure.................................................................................16Figure 15: Positions of the various manual valves in the Cover Gas System (design is preliminary)...17Figure 16: Locations (from left to right) of vessels V-23, E-101 and E-307..........................................18Figure 17: Location of E-304 in Scintillator Plant..................................................................................19Figure 18: Diagram of E-307..................................................................................................................20Figure 19: Diagram of V-23....................................................................................................................21Figure 20: Diagram of E-101..................................................................................................................22Figure 21: Diagram of E-304..................................................................................................................23Figure 22: Pumping down E-101 with a bellows pump........................................................................28Figure 23: Pumping down E-101 with a bellows pump........................................................................29Figure 24: The Upper Utility Room........................................................................................................30Figure 25: The Upper Utility Room........................................................................................................31Figure 26: The Upper Utility Room........................................................................................................31Figure 27: The temporary door and walls in the Utility Room..............................................................32Figure 28: Example of a crack between bolts 6 and 7..........................................................................33Figure 29: Lower UI Leak-Checking Schematic......................................................................................34Figure 30: Graphs of the leaks found in the outer O-ring.....................................................................35

List of TablesTables 1.1-1.4: Trials 1-4 of the Bag Pressure Test and Laser Distance Sensor Reproducibility Test......6Tables 2.1-2.7: Leak Checking Results for June 11, 12,18, 19, 20, 25, 26 and 27 on vessels V-23, E-101, E-307 and E-304.......................................................................................................................24-27Table 3.1: July 22 Inner O-ring Leak Test...............................................................................................35Table 3.2: July 23 Outer O-Ring Leak Test.............................................................................................36

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Section 1: The SNO+ Cover Gas System

To prevent radon permeating the Acrylic Vessel (AV), the detector will be sealed off from the lab environment. The LAB Cover Gas System will enable the detector to be sealed without pressure fluctuations damaging the AV. The system consists of flexible bags to expand and contract, an emergency u-trap as a pressure safety device and the pipes which connect the system to the Universal Interface (UI).

System Design:

The Cover Gas System will consist of 3 240L bags made with an aluminized laminate material. The bags will expand and contract to compensate for pressure fluctuations in the mine and maintain atmospheric pressure in the nitrogen cover gas. The system instrumentation includes:

• At least one oxygen monitor installed in-line to detect leaks. • A vacuum pump to regulate the nitrogen level.• A differential pressure transducer to monitor the difference between the cover gas pressure

and mine pressure (difference between inside and outside of the UI), • Webcams to visually monitor the bags.• Laser distance sensors, placed underneath the bag belly to monitor the bag volume.• Valves:

• Connecting the bags to the UI.• Connecting the nitrogen boil-off to the bags and the oxygen monitor.• Connecting the vacuum pump to the bags and the oxygen monitor• To enable different parts of the system (i.e. the bags and the oxygen monitor) to be

isolated and cleaned by pumping and purgeing with nitrogen. • To isolate the oxygen monitor when necessary for re-calibration.

1.1 - Cover Gas Bags

In May 2013 the final material and construction method for the cover gas bags had been determined and a small test bag had been made and leak-checked. Between May and July of 2013, five full-size cover gas bags were fabricated, leak-tested, and pressure-tested. Follow pressure tests in May 2013, the design of the cover gas system was modified from 4 200L bags to 3 240L bags. This is because the bags were found during pressurizing tests to hold a greater volume of air than originally planned for. Five bags are currently packaged and ready to be installed on site.

Bag Pressure Tests

The purpose of the Bag Pressure Tests were to determine the volume of gas that the full-size bags could hold before becoming pressurized, as well as the maximum pressure that the bags could tolerate. The bags needed to withstand a pressure of 0.3psi or greater, as the Emergency U-tube System will be activated if the cover gas pressure reaches this pressure.

To test the bag volume, a full-size bag was connected to a compressed air supply and U-tube manometer (see Fig. 1), and gradually pressurized by adding 30-50L of air at a time. In the 4 trials a pressure build up of 0.005psi was seen at 262L, so it was concluded that 240L would be the maximum bag volume. Results are shown in Tables 1.1-1.4. The Laser Distance Sensor, which will be used to monitor the bag volume was also tested at this time to determine whether the voltage

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readings it produced for certain distances were reproducible. Details on these results can be found in Section 1.2.

To determine the maximum tolerable pressure, a small test-bag was connected via its fitting to the same U-tube manometer and compressed air supply used for the volume tests. The bag was filled with air while also being pressed down upon. The bag was found to tolerate a pressure of 0.4psi which is sufficient for the purposes of the Cover Gas System.

Figure 1: Bag fitting connects to u-tube manometer and compressed air supply. Laser distance sensor sits underneath the bag belly.

Given the maximum allowable pressure in the bags was 0.1psi, the manometer calculation for the maximum pressure in the bag follows1:

P1-P2 =ρghwhere

• (P1-P2) is the maximum allowable pressure difference between the bag and the atmospheric pressure; 0.1psi is approximately equal to 689.475729 Pa.

• ρ is the density of water, assumed to be 1000 kg/m3.

• g is the acceleration due to gravity, assumed to be 9.81 m/s2

Solving for h, the difference in height between the water level on either side of the u-tube manometer, the change in height for the maximum allowable pressure difference of 0.1 psi was determined to be approximately 7 cm. No error was assumed in any of the values/constants/conversion factors, so the value of h also assumes no error.

1 Banaschewski, Kevin, Results of Covergas Bag Testing. May 16, 2013.

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Bag Pressure Test and Laser Distance Sensor Reproducibility Test

Table 1.1: Trial 1

Volume (L) Voltage (V)Belly Distance(m)

Pressure Difference (m)

0 6.50 0.635 030 6.18 0.590 060 5.69 0.530 090 5.10 0.430 0

120 4.54 0.397 0150 4.33 0.362 0180 4.03 0.334 0210 3.83 0.312 0240 3.55 0.277 0

Table 1.2: Trial 2

Volume (L) Voltage (V) Belly Distance (m) Pressure Difference (m)

0 6.20 0.603 050 5.55 0.509 0

100 4.52 0.388 0150 3.76 0.298 0200 3.34 0.256 0

212.5 3.12 0.228 0262.5 2.92 0.204 0.005

Table 1.3: Trial 3


0 6.67 0.635 050 6.13 0.574 0

100 4.99 0.445 0150 3.96 0.325 0200 3.70 0.296 0210 3.62 0.285 0240 3.38 0.256 0

Table 1.4: Trial 4


0 6.67 0.635 050 5.59 0.515 0

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100 4.75 0.434 0150 3.90 0.317 0200 3.67 0.288 0210 3.58 0.278 0240 3.345 0.252 0

Conclusions:

Since the bags did not become pressurized at 240L of gas in any of the trials it was determined that 3 240L bags would provide sufficient pressure compensation in the Cover Gas System. The laser sensor was also deemed to be sufficiently accurate for distance measurement as the voltage reading consistently corresponded with the distance measured with measuring tape.

Bag Fabrication

The bag material was cut into 74”x37” rectangles (in the Target Room Clean Room). The pieces were then heat-sealed with a hand-held rotary heat-sealer apparatus developed in the summer of 2012. The heat-sealer was moved along the desired seam of the bag very slowly 2-3 times to create an appropriate seal.

Figure 2: Rotary hand-held heat sealer.2

Figure 3: Helium leak-checker with sniffer probe.3

2 M-Pak Systems Online, Constant Heat Roller Series. http://mpaksys.homestead.com/bgpr12.html.3 Inficon, Helium Sniffer Leak Detector. http://products.inficon.com/en-us/nav-

products/Category/ProductGroup/pg_LeakDetectors?path=Products%2F

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Once sealed the bag would be taken for leak-checking. The bag was filled with helium and a helium probe was moved very slowly across the surface of the bag, which is known as the “sniffer” mode on the leak-checker

If no leak was found, the bags were then painted with a black rubberizing spray paint (Plasti-Dip brand) which helped prevent the development of pin-holes in the material. This was done in the negative pressure Team Area in the Integrated Learning Centre for safety purposes. Each side of the bag took a full day to spray paint. The most effective method was to spray a thin layer every half hour throughout the work day.

Figure 4: Pre-rubberizing in the negative pressure room.

Figure 5: Post-rubberizing in the negative pressure room.

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After spray painting the bags were leak-checked again. Only one of the bags was found to have a leak after rubberizing, which was caused by a problematic fitting. The fitting was sanded down and a new bag was made. Five bags are currently available for installation.

Bag Boxes

Boxes were designed and made for transporting the cover gas bags. The aim was to restrict bag movement during travel as much as possible to avoid the development of pin-holes. The boxes were customized to fit the size of the bags which were rolled up on each side and rested on a layer of styrofoam with a hole for the fitting.

Figure 6: Cover gas bag in one of the custom-designed boxes.

1.2 - Cover Gas System Instrumentation

Laser Distance Sensors

Laser distance sensors will be installed under each cover gas bag to monitor the volume. As the bags expand, the bag belly drops down towards the sensor proportional to the change in bag volume. The model selected was the Baumer OADK25I7480, which supplies a voltage reading that corresponds to changes in distance (between 10-100cm) from the sensor.

Calibration:

The distance sensor was arranged in a circuit that included a voltmeter, multimeter, a 500Ω resistor and the laser. It was calibrated by fixing it to a ruler 1 meter away from a wall, and a piece of

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cardboard was moved along the ruler. Every 10cm the voltage was read on the voltmeter.

Figure 7: Laser distance sensor circuit.

Figure 8: Laser distance sensor calibration set-up.

Reproducibility Test:

To test the reproducibility of the voltage reading for different bag volumes, the laser sensor was fixed underneath the same bag being pressure-tested (see Section 1.). As the bag was pressurized the distance of the belly from the laser sensor was measured with measuring tape and the voltage reading from the sensor was recorded in Tables 2.1-2.4. The position sensor was found to successfully produce similar voltage readings for similar distances from the bag.

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Multimeter

500Ω Resistor

Laser

Laser Distance Sensor Circuit

Laser Distance Sensor

100cmRuler

Laser Distance Sensor Calibration Set-up

Stability Test:

To test the long-term stability of the position sensor, the device was positioned as picture in the Fig. 8 for one month continuously. The voltage was recorded regularly and was consistently the same number.

Webcams

A system of webcams will be installed in the Cover Gas System – one for each bag. They will be connected to the DeltaV system for constant visual monitoring of the bags. On the recomendation of Joey D, the Night Owl 4-Channel LTE Full D1 DVR 500GB system has been considered. The purchase includes 4 cameras and a 4 Channel DVR with 500GB harddrive. Cost is yet to be determined.

Figure 9: Potential webcams for monitoring the cover gas bags.4

Oxygen monitors

At least one oxygen monitor will be installed in-line in the cover gas system to monitor for leaks. The presence of oxygen in the system is not particularly harmful in itself to the experiment, but it would indicate a leak which would lead to radon ingress. The requirements for the oxygen monitors were5:

1. Ability to run in flow-through mode, for use in the sealed system.2. The emanation of the oxygen probe and the inside of the analyzer need to meet the

Cover Gas background requirement of 650 atoms/day.3. Sensitivity of 7ppm oxygen in cover gas.

4 Tigerdirect.com, Night Owl LTE-84500 8 Channel LTE D1 DVR - 500GB Hard Drive, 4 Cameras, Indoor/Outdoor, 30' ft Night Vision, H.264 Compression, 240 fps, Motion Activated, PC & Mac Compatible,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=43686155 Fatemighomi, Nasim, Oxygen Monitor Specification. June 2013.

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Sensitivity Calculation 6 : A 1.0E-4mBarL/s leak is equivalent to 2590 radon atoms/day.Concentration of radon in mine air = 5.7E7 atoms/m³Concentration of oxygen = 6.4E24 atoms/m³Conc. Radon/Conc. Oxygen = 9.28E-18 atoms Ra/atoms O22590 Radon atoms/day = 2.72E20 Oxygen atoms/day leakNumber of Nitrogen atoms in system n = PV/RT

= 123·1000Pa·1.25m³/(8.314Pa·m³/mol·K)/293K= 3.8E25

Therefore, sensitivity should be 2.72E20/3.8E25 = 7 ppm Oxygen

4. Compatible with LAB vapour.5. 4-20mA output for the DeltaV system.6. Low leak rate for in-line mounting (less than or equal to 10E-8mBar·L/s acceptable

for Cover Gas System).

Two Oxygen monitors were found and ordered to be tested for sensitivity, compatibility with LAB vapour and radon emanation. The monitors found include:

NTRON Microx Inline ZR

Technology: This probe is a screw-mounted zirconia cioxide sensor inside stainless-steel/aluminum alloy housing. The ceramic zirconia cell allows oxygen ions to pass through at high temperatures, and the movement of the ions generates an EMF which can be measured to determine oxygen concentration. 7

Advantages: Cheap, reliable and sturdy.Disadvantages: Operates at approximately 650°C inside the sensor (40°C outside). This is potentially hazardous as the flash point of LAB is 120°C-140°C. Radon emanation of the housing/zirconia cell may be a problem as well.Cost: $1495.00

Figure 10: Typical in-line set up of NTRON oxygen analyser.8

NTRON Microx Inline ZR Tests:

Following calibration, tests will determine:

6 Fatemighomi, Nasim, Oxygen Monitor Specification. June 2013.7 Toray Engineering Co. Ltd., The Principle of Measurement of Zirconia Oxygen Analyzers. http://www.toray-

eng.com/measuring/tec/zirconia.html.8 NTRON, OEM Oxygen Analysers, 2013. http://www.ntron.com/microx-zirconia.asp.

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– Sensitivity– LAB compatibility– Radon emanation

Test Design and Methodology:

A 2” pipe-tee has been welded with a ¼” pipe connection welded to one end cap and a 10mm M16x1.5mm thread tapped (for the zirconia probe mounting) on the other end cap. The tee will be swageloked to a 1/4” cross which will connect to a helium leak-checker, helium gas supply, a pressure gauge and a vacuum pump.

Leak-Testing the Sensor Mounting and Cross:

Figure 11: Pumping down and leak-testing the zirconia probe mounting and ¼” cross.

The cross was attached to the leak-checker and pumped down. If the pressure reading is on the order of magnitude of 10E-3mBar, then an appropriate vacuum has been achieved and the cross can be leak-tested. This was done by spraying each Swagelok connection and the sensor mounting with a 2-5 second burst of helium gas.

The leak-testing was successful and no significant leak (<10E-8mBar·L/s) was found for the sensor-mounting, which was the area of concern.

Calibration, LAB Compatibility and Sensitivity:

The device will be calibrated by pumping the tee down to vacuum level (10E-3) and

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Helium Leak-Checker

Pipe tee with Oxygen Sensor attached

Pressure Gauge

supplying helium gas into the system, which has a known level of oxygen (2-4ppm9). The reason for using helium gas (rather than nitrogen) is purely convenience, as there is a helium container in the emanation room where tests will take place. Calibration will also determine the sensitivity of the oxygen monitor. Since the sensor claims to have a sensitivity of 1ppm, flowing 2-4ppm oxygen (in the helium) will indicate whether the sensor can produce a reading close to the 1ppm oxygen concentration.

To test LAB compatibility, a small amount of LAB will be placed at an end in the pipe tee. Running the oxygen monitor in helium gas and LAB vapour for at least one full day should determine whether or not the device is compatible with the substance.

Following LAB tests, provided LAB has no apparent effect on the sensor, sensitivity will be re-tested. This will further determine whether LAB damages the sensor - whether it affects the sensitivity. Sensitivity will be tested by again supplying helium gas to the system.

Figure 12: Calibration, sensitivity testing and LAB compatibility testing.

Radon Emanation Test:

To prepare for emanation the pipe tee and cross was disconnected from the helium gas supply and pumped down for roughly three hours. It is important to remove all helium gas from the tee as it emanates a significant amount of radon. Some out-gassing will still occur in the stainless steel after pumping down which will have to be taken into account for the emanation tests.

9 Modern Industrial Equipments Private Ltd., Industrial Gases. http://www.indiamart.com/modern-industrial-equipments/industrial-gases.html.

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Helium gas supply

Pressure Gauge

Pipe tee with Oxygen Sensor attached

Vacuum PumpLAB will go in here

Emanation is currently underway.

Presens OIM PSt6

Technology: Polymer optical fibre inside a screw-mounted stainless steel fitting. A blue-green LED light excites the oxygen sensor to emit fluorescence, and when the sensor encounters an oxygen molecule the excess energy is transferred to the oxygen molecule which decreases or “quenches” the fluorescence signal10.Advantages: Temperature during operation and radon emanation is not likely to be an issue. The Fibox 3 LCD Trace, which is the fiber-optic oxygen transmitter, can have inputs from multiple oxygen sensors, in case more than one is needed for the cover gas system. (The technology is very cool!)Disadvantages: Expensive.Cost: Probe + Transmitter = $1 308.00 + $8 542.00 = $9 850.00

No testing apparatus has been designed for the Presens monitor yet.

Vacuum Pump

A vacuum pump will be installed in the Cover Gas System in for the purpose of purging the system with Nitrogen and regulating Nitrogen levels. The pump selected was the Pfeiffer Vacuum MVP-006 Diaphragm Pump. It was chosen for it's small size, which gives a slow and manageable pumping rate of 6L/min. Further properties include:

• 24 (± 10%) V DC power supply.• G 1/8” flange (in and out) with common metric vacuum thread standard.11 (It will need

adapter for the 1/4” pipe it connects to.)The cost of the pump was $1825.00.

Figure 13: The Pfeiffer Vacuum MVP 006 diaphragm pump.12

10 Presens Precision Sensing GmbH, The Smart Measurement Method. http://www.presens.de/products/brochures/category/sensor-probes/brochure/oxygen-probes.html#tab-probes.

11 ANVER Corp Vacuum Fittings Explanation, 2013. http://www.anver.com/document/vacuum%20components/vacuum%20cups/Fittings/vacuum-fittings-conversions.htm

12 Pfeiffer Vacuum, MVP 006-4, Diaphragm Pump, 24V DC. http://www.pfeiffer-vacuum.com/products/diaphragm-pumps/mvp-006/onlinecatalog.action?detailPdoId=4223

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Figure 14: Graph of pumping speed vs. pressure for the MVP 00613.

Valves

Two kinds of valves will be installed in the cover gas system for (1) 2” piping and (2) 1/4” piping (see Fig. 15).(1) Three 2” Edge-welded or 3 3/8” CF flanged valves will connect the bags to the UI. The requirements were as follows:

• All-metal (stainless steel, ultra-pure)• 2” tube or 3 3\8” CF flange connection

The valve of choice is the Carten Controls HB 2000-10LV, which was the only valve found to fit all the requirements. Due to the cost of a new model ($3 165.00), alternative options are currently being investigated.

(2) There will also be (likely) four 1/4” VCR manual or actuated valves, positioned in front of:• The boil-off nitrogen supply.• The vacuum pump.• Each bag.• The oxygen monitor.These valves are critical for cleaning the system, as it will be possible to isolate system

components (i.e. the bags or the oxygen monitor) to pump and purge with boil-off nitrogen. Also when the oxygen monitor needs re-calibration, it can be isolated from the bags to perform this operation. If there is a leak in one of the bags, then the valves going to the bags can be closed until the leaking bag is identified. These valves are reasonably priced and available from Swagelok company.

13 Pfeiffer Vacuum, MVP 006-4, Diaphragm Pump, 24V DC. http://www.pfeiffer-vacuum.com/products/diaphragm-pumps/mvp-006/onlinecatalog.action?detailPdoId=4223#product-characteristic

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Figure 15: Positions of the various manual valves in the Cover Gas System (design is preliminary).

Section 2: Scintillator Plant Construction

2.1 - Leak-checking

To ensure LAB purity it is important that the vessels being installed in the Scintillator Plant be vacuum tight. The target level for the Uranium chain due to radon permeation leads to a vacuum leak tightness requirement of 10E-6mbar·L/sec (for all phases of the experiment). Although Rn background is less critical for the double beta decay phase, 210Pb plateout will collect as background for the solar neutrino phase. Krypton and Argon levels require the same air leak rate. Thus in order to achieve below target background levels, vessel fittings are required to have a leak rate of 10E-9mbar·L/sec. Vessels and pumps require a leak rate of 10E-8mbar·L/sec 14.

On the days that I was assigned to work with Andrew Stripay underground, I was able to assist with helium leak-checking and torquing down the Scintillator Plant vessels to prepare them for installation. For leak checking each vessel would be pulled under a vacuum and a small amount of helium would be sprayed on the fitting being tested. Once helium was sprayed, the leak rate was recorded approximately every five minutes or more frequently depending on the speed of the leak (to prevent missing the peak leak rate). Once the peak was reached the leak rate was recorded less frequently as the leak rate returned to acceptable levels. The vessels that were leak-tested include V23, E-101, E-307 and E-304. The following diagrams give a visual description of each vessel and indicate their locations n the Scintillator Plant.

14 Ford, Richard, Scintillator Process Systems. March 4, 2012.

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2” Edge-welded or 3 3/8” CF

1/4” VCR

Figure 16: Locations (from left to right) of vessels V-23, E-101 and E-307.

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Figure 18: Diagram of E-307.

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Figure 19: Diagram of V-23.

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Figure 20: Diagram of E-304

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Figure 21: Diagram of E-101

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Table 2.1: June 11

Time (am/pm) Pressure (mBar) Leak Rate (mBar·L/s)

Fitting Vessel

9:30 1.5E-2 4.1E-8 LT2 V23

9:43 1.5E-2 4.0E-8

9:45 1.5E-2 3.9E-8 LT2A

10:30 1.5E-2 3.2E-8

10:54 1.5E-2 3.0E-8

Table 2.2: June 12


Fitting Vessel

7:16 9.0E-3 8.7E-9 V23

7:20 9.0E-3 8.5E-9 LT2A (adapter)

7:35 9.0E-3 8.3E-9 LT2

7:40 9.0E-3 8.6E-9

7:41 9.0E-3 8.7E-9

7:45 9.0E-3 8.6E-9

8:55 9.0E-3 1.3E-8

9:10 9.0E-3 1.2E-8

9:40 9.0E-3 1.2E-8

9:50 9.0E-3 1.2E-8 N4

9:55 9.0E-3 1.2E-8

10:40 9.0E-3 1.1E-8 SG2

10:50 9.0E-3 1.1E-8

10:55 9.0E-3 1.1E-8 N5

11:00 9.0E-3 1.1E-8

11:10 9.0E-3 1.1E-8

11:12 9.0E-3 1.1E-8 N2

11:15 9.5E-3 1.9E-6

11:30 9.5E-3 1.9E-6

11:35 1.0E-2 1.6E-6

11:40 1.0E-2 1.5E-6

11:55 9.9E-3 1.1E-6

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12:00 9.5E-3 8.7E-7

12:21 9.0E-3 5.4E-7

1:30 8.3E-3 1.1E-7

2:15 8.3E-3 3.7E-8

2:25 8.3E-3 2.9E-8 N1

2:30 8.3E-3 2.9E-8 P1

2:35 8.3E-3 2.5E-8 SG1

2:40 8.0E-3 2.4E-8 LT1A

2:45 8.0E-3 2.6E-8 LT1

2:50 8.0E-3 5.1E-8 N7

Table 2.3: June 18


Fitting Vessel

11:49 4.5E-2 4.3E-7 E-101

12:49 1.8E-2 7.5E-8

1:05 1.7E-2 6.8E-8

1:10 1.7E-2 4.2E-6

Table 2.3: June 19


Fitting Vessel

12:30 1.9E-2 7.3E-8 E-101

12:52 1.6E-2 5.1E-8

1:11 1.4E-2 3.7E-8

1:44 1.3E-2 2.4E-8

2:13 1.2E-2 2.1E-8

Table 2.4: June 20


Fitting Vessel

7:14 1.1E-2 1.2E-9 E-101

7:20 1.0E-2 3.6E-9

7:30 9.5E-3 8.7E-9

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7:45 9.2E-3 1.0E-10

8:10 9.2E-3 1.0E-10 N4

8:15 9.0E-3 1.0E-10

8:20 9.0E-3 7.2E-9 N3

8:34 9.0E-3 1.2E-8

8:41 9.0E-3 1.5E-8

8:53 9.0E-3 2.0E-8

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9:48 9.0E-3 1.2E-8

10:06 9.0E-3 9.6E-9

11:30 9.0E-3 6.2E-9

11:49 9.0E-3 6.7E-9

11:55 9.0E-3 6.6E-9

1:50 9.0E-3 6.1E-9

1:51 8.3E-3 3.2E-8 N5

2:50 8.3E-3 9.3E-9

2:52 8.3E-3 9.1E-9 N2

2:55 8.3E-3 8.9E-9

2:58 8.3E-3 2.1E-8 N6

3:00 8.3E-3 3.1E-6 Thermocouple

Table 2.5: June 25


Fitting Vessel

11:05 7.7E-3 1.3E-9 Thermocouple E-101

11:10 7.7E-3 1.3E-9

11:12 7.7E-3 6.0E-7 NPT

11:14 7.7E-3 5.6E-7

11:16 7.7E-3 5.0E-7

11:17 7.7E-3 4.8E-7

11:18 7.7E-3 4.7E-7

Table 2.6: June 26


Fitting Vessel

7:27 7.7E-3 1.0E-9 E-101

7:30 7.7E-3 9.9E-10 N1

7:35 7.7E-3 1.0E-9

7:40 7.7E-3 1.0E-9

7:41 7.7E-3 1.1E-9

7:45 7.7E-3 1.1E-9

7:46 7.7E-3 1.2E-9

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7:50 7.7E-3 1.3E-9

7:51 7.7E-3 1.4E-9

7:55 7.7E-3 1.6E-9

7:57 7.7E-3 1.7E-9

8:05 7.7E-3 2.3E-9

8:15 7.7E-3 2.8E-9

8:25 7.7E-3 3.2E-9

8:34 7.7E-3 3.4E-9

8:40 7.7E-3 3.5E-9

8:50 7.7E-3 3.6E-9

9:06 7.7E-3 1.7E-7 NPT



Table 2.7: June 27


Fitting Vessel

7:18 7.7E-3 1.0E-10 N2 E-304

7:25 7.7E-3 1.5E-10

7:28 7.7E-3 1.0-1.3E-10

7:35 7.7E-3 1.9-2.5E-10

7:40 7.7E-3 2.8-3.0E-10

7:45 7.7E-3 4.5-4.9E-10

7:53 7.7E-3 6.6-7.OE-10

7:58 7.7E-3 7.5-8.0E-10

8:08 7.7E-3 7.8-8.1E-10

8:15 7.7E-3 7.5E-10

8:28 7.7E-3 7.0-7.4E-10 N1

8:43 7.7E-3 7.0-7.2E-10

8:51 7.7E-3 6.8-7.1E-10

9:00 7.7E-3 6.2-6.4E-10

9:05 7.7E-3 6.3-6.5E-10

9:17 7.7E-3 6.1-6.5E-10

9:26 7.7E-3 5.6-5.8E-10 N3

30

9:37 7.7E-3 5.9-6.4E-10

9:47 7.7E-3 1.5E-7 NPT

9:48 7.7E-3 1.7E-7 Thermocouple

9:49 7.7E-3 2.0E-7

Figure 22: Pumping down E-101 with a bellows pump.

31

Figure 23: Pumping down E-101 with a bellows pump.

2.2 - Scintillator Plant Construction

I was also able to contribute to the construction of the Scintillator Plant on the days I was assigned to work in the Utility Room. My activities included:

• Covering vessels with plastic tarp and taping (to protect from drywall dust).• Setting up temporary tarp walls and ceilings to prevent dust contamination in clean lab area.• Vacuuming.• Painted scaffolding.• Disposing of spare drywall pieces.• Rewired network cables into drywall area.• Carrying construction materials (scaffolding, etc.) to Utility Room.

34

Figure 24: Magnificent gift-wrapping skills were developed.

36

Figure 26: The Utility Room is getting a little crowded.

Figure 27: The Upper Utility Room.

37

Figure 28: The temporary door and walls in the Utility Room.

Section 3: Lower Universal Interface Leak-Checking

The first connection point between the AV and the calibration hardware is the Lower UI. To ensure that no contamination from outside media permeates the detector, it is critical that the seal between the UI and the detector is airtight. The seal consists of two fluorocarbon O-rings (a double O-ring seal), which is the sole separation volume between the outside hardware and the detector. The maximum allowable leak rate of the seal is 10E-8 mBar·L/s. Additionally the seal will be pumped and purged with nitrogen gas to prevent Radon entering the air in the volume. Leak testing activities have found that in the worst-case scenario the seal meets this criterion. More specifically, it was found that the outer O-ring leaks significantly more than the inner O-ring. Thus, the total leak rate of the seal was found to exceed the required value by several orders of magnitude15.

On July 22 and 23 I assisted Benjamin Davis-Purcell in leak-testing the inside and outside of the UI. There are six cracks between the teflon spacer pieces as there are six pieces each for the inner and outer spacers. Bursts of helium (5 seconds at 29.5psi) were sprayed into these cracks, as they were the optimum way to get helium past the spacers to reach the O-rings. Once the helium was sprayed the crack was sealed with aluminum tape to ensure the helium was forced into the

15 Davis-Purcell, Benjamin, Lower UI Leak-Checking. August 30, 2013.

38

crack and reaching the inner or outer O-ring. At the same time helium was being blown, the leak-checker was on and pumping the volume to vacuum. The leak rate was monitored at 15-second intervals for 2 minutes, or longer if the leak rate was still increasing after 2 minutes. If a leak was detected, then helium would also be sprayed nearby the crack (see Fig. 27) to determine whether it was indeed the source of the leak. Each crack is denoted by the bolts it lies between (e.g. bolts 6/7). The results are summarized as follows16:

• Inner O-Ring: No leak rate increase detected.• Outer O-Ring: - No measurable increase between bolts 18/19, 24/25, 30/31, 5/6, 7, 7/8,

8/9, 9/10, 10/11, 11/12, 13/14- Slight increase at bolts 12/13, 36/1- Very large increase at 6/7

Figure 29: Example of a crack between bolts 6 and 717.

16 Davis-Purcell, Benjamin, Lower Universal Interface. August 15, 2013.17 Davis-Purcell, Benjamin, Lower UI Leak-Checking. August 30, 2013.

39

Figure 30: Lower UI Leak-Checking schematic.

40

UI

Helium Leak-checker

Leak-checker exhaust – run out of DCR into SNO+ Control Room

Pumping down O-ring volume

Lower UI Leak-Checking Schematic

Figure 31: Graphs of the leaks found in the outer O-ring18.

Table 3.1: July 22 Inner O-ring Leak Test

Bolt 6/7 12/13 18/19

Time (s) Pressure (mBar)

Leak Rate (mBar·L/s)

Pressure Leak Rate Pressure Leak Rate

0 3.00E-1 9.20E-7 3.20E-1 1.00E-7 3.3E-1 1.20E-7

15 3.00E-1 9.20E-7 3.20E-1 1.00E-7 3.3E-1 1.20E-7

30 3.00E-1 9.20E-7 3.20E-1 1.00E-7 3.3E-1 1.20E-7

45 3.00E-1 9.20E-7 3.20E-1 1.00E-7 3.3E-1 1.10E-7

60 3.00E-1 9.20E-7 3.20E-1 1.00E-7 3.3E-1 1.10E-7

75 3.00E-1 9.10E-7 3.20E-1 1.00E-7 3.3E-1 1.10E-7

90 3.00E-1 9.00E-7 3.20E-1 1.00E-7 3.3E-1 1.10E-7

18 Davis-Purcell, Benjamin, Lower UI Leak-Checking. August 30, 2013.

41

105 3.00E-1 9.00E-7 3.10E-1 1.00E-7 3.3E-1 1.10E-7

120 3.00E-1 9.00E-7 3.10E-1 1.00E-7 3.3E-1 1.10E-7

(Continued)

Bolt 24/25 36/1 30/31




0 2.80E-1 7.70E-8 2.90E-1 8.40E-8 2.80E-1 8.30E-8

15 2.80E-1 7.70E-8 2.90E-1 8.30E-8 2.80E-1 8.30E-8

30 2.80E-1 7.70E-8 2.90E-1 8.30E-8 2.80E-1 8.30E-8

45 2.80E-1 7.70E-8 2.90E-1 8.30E-8 2.80E-1 8.30E-8

60 2.80E-1 7.70E-8 2.90E-1 8.30E-8 2.80E-1 8.20E-8

75 2.80E-1 7.70E-8 2.90E-1 8.30E-8 2.80E-1 8.20E-8

90 2.80E-1 7.70E-8 2.90E-1 8.30E-8 2.80E-1 8.20E-8

105 2.80E-1 7.70E-8 2.90E-1 8.30E-8 2.80E-1 8.10E-8

120 2.80E-1 7.60E-8 2.90E-1 8.30E-8 2.80E-1 8.00E-8

Table 3.2: July 23 Outer O-Ring Leak Test

Bolt 6/7 12/13 18/19




0 2.90E-1 1.40E-7 3.00E-1 1.40E-7 2.3E-1 2.20E-7

15 2.90E-1 1.24E-2 3.00E-1 1.40E-7 2.3E-1 2.10E-7

30 2.90E-1 6.70E-4 3.00E-1 1.50E-7 2.3E-1 2.20E-7

45 2.90E-1 7.70E-4 3.00E-1 1.40E-7 2.3E-1 2.10E-7

60 2.90E-1 8.00E-4 3.00E-1 1.40E-7 2.3E-1 2.10E-7

75 2.90E-1 8.20E-4 2.90E-1 1.40E-7 2.3E-1 2.10E-7

90 2.90E-1 7.90E-4 2.90E-1 1.40E-7 2.3E-1 2.10E-7

105 2.90E-1 7.60E-4 2.90E-1 1.40E-7 2.3E-1 2.10E-7

120 2.90E-1 7.00E-4 2.90E-1 1.40E-7 2.3E-1 2.10E-7

135 2.90E-1

150 2.90E-1

165 2.90E-1 5.70E-4

180 2.90E-1 5.50E-4

42

195 2.90E-1 5.30E-4

210 2.90E-1 5.00E-4

225 2.90E-1 4.80E-4

240 2.90E-1 4.50E-4

255 2.90E-1 4.10E-4

270 2.90E-1 4.00E-4

285 2.90E-1 3.70E-4

300 2.90E-1 3.50E-4

315 2.90E-1 3.20E-4

330 2.90E-1 3.10E-4

345 2.90E-1 2.90E-4

360 2.90E-1 2.80E-4

375 2.90E-1

390 2.90E-1

405 2.90E-1 2.50E-4

420 2.90E-1 2.40E-4

435 2.90E-1 2.20E-4

450 2.90E-1 2.10E-4

465 2.90E-1 1.90E-4

480 2.90E-1 1.80E-4

495 2.90E-1 1.70E-4

510 2.90E-1 1.60E-4

525 2.90E-1 1.50E-4

540 2.90E-1 1.40E-4

555 2.90E-1 1.30E-4

570 2.90E-1 1.20E-4

585 2.90E-1 1.10E-4

600 2.90E-1 1.10E-4

615 2.90E-1 1.00E-4

630 2.90E-1 9.90E-5

645 2.90E-1 9.30E-5

660 2.90E-1 8.70E-5

675 2.90E-1 8.20E-5

690 2.90E-1 7.70E-5

43

705 2.90E-1 7.10E-5

720 2.90E-1 6.40E-5

735 2.90E-1 6.10E-5

750 2.90E-1 5.50E-5

765 2.90E-1

780 2.90E-1 4.80E-5

795 2.90E-1 4.40E-5

810 2.90E-1 4.10E-5

825 2.90E-1 3.80E-5

840 2.90E-1 3.60E-5

855 2.90E-1 3.20E-5

870 2.90E-1 3.00E-5

885 2.90E-1 2.70E-5

900 2.90E-1 2.50E-5

915 2.90E-1 2.30E-5

930 2.90E-1 2.10E-5

945 2.90E-1 1.90E-5

960 2.90E-1 1.80E-5

975 2.90E-1 1.60E-5

990 2.90E-1 1.40E-5

1005 2.90E-1 1.30E-5

1020 2.90E-1 1.20E-5

1035 2.90E-1 1.10E-5

1050 2.90E-1 1.10E-5

1065 2.90E-1 1.00E-5

1080 2.90E-1 9.40E-6

1095 2.90E-1 8.50E-6

1110 2.90E-1 7.90E-6

1125 2.90E-1 7.20E-6

1140 2.90E-1 6.80E-6

1155 2.90E-1 6.20E-6

1170 2.90E-1 5.80E-6

1185 2.90E-1 5.30E-6

1200 2.90E-1 5.00E-6

44

1215 2.90E-1 4.60E-2

1230 2.90E-1 4.20E-6

1245 2.90E-1 4.00E-6

1260 2.90E-1 3.70E-6

1275 2.90E-1 3.40E-6

1290 2.90E-1 3.20E-6

1305 2.90E-1 2.90E-6

1320 2.90E-1 2.80E-6

1335 2.90E-1 2.60E-6

1350 2.90E-1 2.40E-6

1365 2.90E-1 2.30E-6

1380 2.90E-1 2.10E-6

1395 2.90E-1 1.90E-6

1410 2.90E-1 1.80E-6

1410 2.90E-1 1.70E-6

1425 2.90E-1 1.60E-6

1440 2.90E-1 1.50E-6

1455 2.90E-1 1.40E-6

1470 2.90E-1 1.40E-6

1485 2.90E-1 1.30E-6

1500 2.90E-1 1.20E-6

1515 2.90E-1 1.20E-6

1530 2.90E-1 1.10E-6

1545 2.90E-1 1.00E-6

1560 2.90E-1 1.00E-6

1575 2.90E-1 9.90E-7

1590 2.90E-1 9.60E-7

1605 2.90E-1 9.20E-7

1620 2.90E-1 8.80E-7

1635 2.90E-1 8.00E-7

1650 2.90E-1 7.80E-7

1665 2.90E-1 7.50E-7

1680 2.90E-1 7.30E-7

1695 2.90E-1 7.10E-7

45

1710 2.90E-1 6.90E-7

1725 2.90E-1 6.70E-7

1740 2.90E-1 6.50E-7

1755 2.90E-1 6.30E-7

1770 2.90E-1 6.20E-7

1785 2.90E-1 6.10E-7

1815 2.90E-1 6.00E-7

1830 2.90E-1

1845 2.90E-1

1860 2.90E-1 5.80E-7

1875 2.90E-1 5.70E-7

1890 2.90E-1 5.60E-7

1905 2.90E-1 5.50E-7

1920 2.90E-1 5.30E-7

1935 2.90E-1 5.10E-7

1950 2.90E-1 5.00E-7

1965 2.90E-1 4.90E-7

1980 2.90E-1 4.90E-7

1995 2.90E-1 4.90E-7

2010 2.90E-1 4.80E-7

(Continued)

Bolt 24/25 36/1 30/31




0 2.40E-1 2.40E-7 2.50E-1 3.70E-7 2.80E-1 8.30E-8

15 2.40E-1 2.40E-7 2.50E-1 3.50E-7 2.80E-1 8.30E-8

30 2.40E-1 2.40E-7 2.50E-1 3.10E-7 2.80E-1 8.30E-8

45 2.40E-1 2.40E-7 2.50E-1 2.90E-7 2.80E-1 8.30E-8

60 2.40E-1 2.40E-7 2.50E-1 2.90E-7 2.80E-1 8.20E-8

75 2.40E-1 2.40E-7 2.50E-1 3.00E-7 2.80E-1 8.20E-8

90 2.40E-1 2.30E-7 2.50E-1 3.10E-7 2.80E-1 8.20E-8

105 2.40E-1 2.30E-7 2.50E-1 3.30E-7 2.80E-1 8.10E-8

120 2.40E-1 2.30E-7 2.50E-1 3.40E-7 2.80E-1 8.00E-8

46

135 2.50E-1

150 2.50E-1

165 2.50E-1

180 2.50E-1 3.70E-7

195 2.50E-1 3.90E-7

210 2.50E-1 3.90E-7

225 2.50E-1 3.90E-7

240 2.50E-1 3.90E-7

255 2.50E-1 3.90E-7

270 2.50E-1 3.80E-7

285 2.50E-1 3.80E-7

300 2.50E-1 3.80E-7

315 2.50E-1 3.80E-7

330 2.50E-1 3.80E-7

345 2.50E-1 3.80E-7

360 2.50E-1 3.70E-7

375 2.50E-1 3.70E-7

390 2.50E-1 3.70E-7

405 2.50E-1 3.60E-7

420 2.50E-1 3.60E-7

435 2.50E-1 3.60E-7

450 2.50E-1 3.60E-7

465 2.50E-1 3.60E-7

480 2.50E-1 3.50E-7

495 2.50E-1 3.50E-7

510 2.50E-1 3.50E-7

525 2.50E-1 3.40E-7

540 2.50E-1 3.40E-7

555 2.50E-1 3.40E-7

570 2.50E-1 3.30E-7

585 2.50E-1 3.30E-7

600 2.50E-1 3.30E-7

615 2.50E-1 3.30E-7

630 2.50E-1 3.30E-7

47

645 2.50E-1 3.30E-7

660 2.50E-1 3.30E-7

675 2.50E-1 3.20E-7

48

SNO+ Summer Report

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Transcript of SNO+ Summer Report