Double Chooz Neutrino Project: Slow Monitoring and Recording System

1. Louisiana Tech University Double Chooz Neutrino Project:Slow Monitoring and Recording System Students: Richard Chevious (Senior - Louisiana Tech University ) and James Hazelton (Junior - Oklahoma State University) Advisor: Dr. Glenn Horton-Smith

2. Purpose • To design and test certain aspects of the Slow Monitoring and Recording system for the Double Chooz neutrino project, focusing on the system of temperature and magnetic field sensors which will monitor the status of the final detector.

3. Why? • Neutrinos are probes into many cosmological events such as supernova and nuclear processes at the center of stars. • With this information, scientists can gain a better understanding of the universe.

4. Reactor Neutrinos are produced by nuclear beta decay. An example of b-decay Background Neutrinos • Elementary particle • Interact through the weak force and gravity • First theorized in1930 by Wolfgang Pauli • First discovered in1956 by Clyde Cowan, Frederick Reines, F. B. Harrison, H. W. Kruse, and A. D. McGuire. • There are three types of neutrinos: electron (ne), muon (nm) and tau (nt) • Electric charge: 0 • Spin: 1/2 Neutrinos are elementary particles that weakly interact with normal matter and move at nearly the speed of light. Their properties make them important as a probe into the processes inside of the Sun or in a nuclear reactor. Provided by Reference 2.

5. Background Neutrino Detection A process called inverse beta decay is used to detect neutrinos. The process entails a proton and an antineutrino collision creating a positron and neutron. (Shown in the equation above.) Then, a positron and electron annihilate to produce two or more photons which are detected. (Shown in the equation above.) Provided by Some Doctors.

6. Background Double Chooz Double Chooz is investigating the value of the q13 neutrino mixing angle. They want to measure this angle within the range of 0.2 to 0.03-0.02 within three years of data taking. In order to achieve this scientific goal the detectors need monitoring systems to ensure 1% or less error in measurements. Provided by Reference 1.

7. Materials • HMC2003 Three-Axis Magnetic Sensor Hybrid • DS18S20 High-Precision 1-Wire Digital Thermometer • DS2450 1-Wire Quad A/D Converter • Buffer Oil • Thermally Conductive Epoxy • Clear Epoxy • Solenoids • Clear Acrylic

8. Materials Solenoids, which we used to create uniform magnetic fields.

9. Materials 4-Channel ADC: Converts the sensors’ analog signal into digital form Also used for triggering the set/reset circuit 3-Axis Magnetic Field Sensor: OneWire compatible magnetic field sensor with a range of +/-2.5 Gauss DS1820 Thermometer: OneWire compatible programmable resolution thermometer Provided by Reference 4.

10. Projects Testing and calibrating sensors Compatibility testing of components and epoxies with buffer oil Designing the Set/Reset circuit and improving the software interface Fabricating the mount unit for sensors Designing and building the integrated circuit board Testing prototype

11. Set/Reset Circuit When the magnetic sensors encounter a large magnetic field, the magnetic domains begin to skew, producing inaccurate readings. Solution: Create a circuit which will reset the domains periodically. Magnetic Domains for Magneto-resistive element. Provided by Reference 4. Both provided by Reference 4. Set/Reset pulse Diagram for an S/R Circuit

12. Prototype PCB for Sensors Key: Green: Bottom of Board Yellow: Outline of Components Red: Top of Board Picture of PCB

13. Prototype Mount for Sensors Cable Sensors in a box Holes Cable Box PCB Board with Sensors Picture of Mount with Sensors

14. Preliminary Placement of Sensors in the Tank Mounts for Sensors

15. PMT Dimensions (Lengths given in mm) Provided by Reference 3.

16. Results

17. When compared with a pre-calibrated magnetic field sensor, ours was found to be very accurate.

18. Temperature sensors covered in thermally conductive epoxy reacts to changes faster than the clear epoxy. The fastest reaction time came with no epoxy at all

19. Testing over several days has shown the program can run for an extended period.

20. Preliminary oil spectrum data has suggested that in the oil exposed to our Teflon coated wire there is a small increase in absorbance around blue because of the printed letters on the insulation.

21. Non-Graphical Results • Fabricated prototype sensor mount and cover • Set up the ADC to send pulses to the S/R circuit • Began soldering components to the circuit board.

22. Conclusion When implemented, the final system of sensors will be able to monitor the magnetic field and temperature inside the detector, which will then be taken into consideration when calculating the results of Double Chooz. With information about the inside of the detector, it will be easier to eliminate many erroneous results, leading to measurements with greater precision.

23. Acknowledgements • The National Science Foundation - REU • Kansas State University – Physics Dept. • Dr. Glenn Horton-Smith • Dr. Larry Weaver • Dr. Kristan Corwin • Dante Amoroso – Technical Assistance • Dr. Sorenson, for the use of Dante • Scott Chainey – Technical Assistance • Russ Reynolds – Technical Assistance • and the rest of the Physics REU

24. References • http://doublechooz.in2p3.fr/Public/public.php • http://en.wikipedia.org • http://neutrino.phys.ksu.edu/~gahs/doublechooz/DC_SlowMRS/ • http://www.ssec.honeywell.com/