1. Neutrino Physics - Lecture 4 Steve Elliott LANL Staff Member UNM Adjunct Professor 505-665-0068, elliotts@lanl.gov

2. Spring 2007Steve Elliott, UNM Seminar Series2 Lecture 4 Outline Neutrinos from the Sun The neutrinos Past experiments What we know and what we want to learn

3. Spring 2007Steve Elliott, UNM Seminar Series3 Cl Results 2.56 ± 0.16 ± 0.16 SNU Expect 7.5 SNU

4. Spring 2007Steve Elliott, UNM Seminar Series4 SAGE and Gallex (GNO) 71 Ga( e,e) 71 Ge 71 Ge has 11.4 day half life. Expose Ga to neutrinos Extract Ge and count via its decay Decays of 71 Ge are by electron capture: the signature is the 1.2 or 10.4 keV x rays, Auger electrons

5. Spring 2007Steve Elliott, UNM Seminar Series5 SAGE Operations 1.Add carrier to Ga. 2.After about 3-4 weeks, extract Ge carrier and solar neutrino induced Ge. 3.Synthesize counter gas and fill proportional counter. 4.Count sample for about 6 months.

6. Spring 2007Steve Elliott, UNM Seminar Series6 Map to SAGE

7. Spring 2007Steve Elliott, UNM Seminar Series7 Baksan Valley, UG Laboratory

8. Spring 2007Steve Elliott, UNM Seminar Series8 Source Calibration 92.4% enriched in 50 Cr 512.7 g of Cr Irradiated for ~3 mnths 517 kCi activity

9. Spring 2007Steve Elliott, UNM Seminar Series9 Reactor Layout 10 reactors Each can hold 8 tons of Ga Kept warm so Ga is liquid

10. Spring 2007Steve Elliott, UNM Seminar Series10 Proportional Counters R: recombination IC: ionization chamber PC: proportional chamber GC: Geiger counter D: continuous discharge R IC PC GC D Voltage Collected Ions

11. Spring 2007Steve Elliott, UNM Seminar Series11 Proportional Counter Spectrum

12. Spring 2007Steve Elliott, UNM Seminar Series12 Results - Solar Rate Expect 128 SNU Each run saw about 6 signal Events.

13. Spring 2007Steve Elliott, UNM Seminar Series13 Gran Sasso Italy: Not too far from Rome

14. Spring 2007Steve Elliott, UNM Seminar Series14 GNO Layout

15. Spring 2007Steve Elliott, UNM Seminar Series15 GALLEX Results Expected 128 SNU

16. Spring 2007Steve Elliott, UNM Seminar Series16 Kamiokande & SuperK Elastic scattering of e - in a large water detector Mostly sensitive to e because CC cross section is about 6x higher than NC

17. Spring 2007Steve Elliott, UNM Seminar Series17 Cherenkov Radiation “Electrons in the atoms of the medium will be displaced and polarized by the passing EM field of a charged particle. Photons are emitted as an insulator's electrons restore themselves to equalibrium after the disruption has passed. (In a conductor, the EM disruption can be restored without emitting a photon.) In normal circumstances, these photons destructively interfere with each other and no radiation is detected. However, when the disruption travels faster than the photons themselves travel, the photons constructively interfere and intensify the observed radiation.” Wikipedia

18. Spring 2007Steve Elliott, UNM Seminar Series18 Photomultiplier Tubes

19. Spring 2007Steve Elliott, UNM Seminar Series19 SuperKamiokande Characteristics 50,000 t water 11,146 20” pmt 1,885 8” pmt

20. Spring 2007Steve Elliott, UNM Seminar Series20 SuperK Data

21. Spring 2007Steve Elliott, UNM Seminar Series21 SNO ES, CC, and NC CC: d( e, pp)e - –Sensitive only to e NC: d( x, np) x –Sensitive to all x NC/CC ratio

22. Spring 2007Steve Elliott, UNM Seminar Series22 SNO’s Location < 100  /day

23. Spring 2007Steve Elliott, UNM Seminar Series23 The SNO Detector 9438 inward & 91 outward With concentrators = 54% coverage Control room Vectran support ropes Urylon liner 5300 tonnes light water 1000 tonnes heavy water 1700 tonnes light water 2039 m to surface 10 11 m to Sun 12 m diameter acrylic vessel Support structure for 9500 PMTs, concentrators Norite rock

24. Spring 2007Steve Elliott, UNM Seminar Series24 SNO Calibration \Electronics Calibrations Built-in programmable pulsers \Optical Calibrations Laser ball: attenuation, scattering, reflectivity \Energy Calibrations 16 N source: 16 O(n,p) 16 N *  -tagged 6.1-MeV  source 8 Li Source: e - spectrum similar to 8 B 252 Cf source: fission neutron source Encapsulated U/Th source (low-E  ’s) 3 H(p,  ) 4 He: 19.8-MeV  Triggered U: Th sources (low-E  ’s) Michel electrons

25. Spring 2007Steve Elliott, UNM Seminar Series25 An example Event: atmospheric neutrino

26. Spring 2007Steve Elliott, UNM Seminar Series26 SNO data Radius of event vertex Angle with Sun

27. Spring 2007Steve Elliott, UNM Seminar Series27 Event Energy

28. Spring 2007Steve Elliott, UNM Seminar Series28 NC vs. CC