# Presentation: 662816

## (ORNL)

**(ORNL**)

**Yu.Efremenko**
**University of Tennessee**
**(Nashville, March 7****th**** 2001)**

## Outline

**What is the SNS**
**Neutrino Production at the SNS**
**Why neutrinos?**
**What is ORLaND**
**Neutrino Physics at ORLaND**
**Summary**

## Spallation Neutron Source 

- World’s most advancedaccelerator-based pulsed-neutron source
- Neutron beams with more than 10 times the intensity of any existing pulsed neutron source
- 1 GeV, 2MW proton LINAC with accumulator ring
- 60 Hz pulses with FWHM less than 400 nsec
- 21014 protons per pulse delivered to the mercury target

**Notes:**
Message: Together, HFIR and SNS will constitute the world’s most powerful resource for neutron sciences, positioning ORNL for leadership in this area. Key elements of the initiative: supporting SNS construction/commissioning, completing the HFIR upgrades, developing innovative programs to take advantage of the expanded capabilities afforded by these investments, and developing an intellectual center to support extended partnerships and outreach activities for the estimated 2000 users per year expected to take advantage of these capabilities.
Key Scientific Accomplishments:
SNS: Nation’s largest science project; will ensure U.S. leadership in neutron scattering well in the next century.
HFIR: ORNL’s other billion dollar facility, being upgraded to include a world-class cold source and unsurpassed steady-state neutron scattering capabilities. HFIR complements SNS for neutron scattering experiments that benefit from steady-state beams; it also provides unique capabilities for isotope production and materials irradiation. 
Needed: To take advantage of DOE’s investment in neutron sciences at ORNL. 
Scientific Impact: New insights into the nature, structure, and behavior of materials, with far-reaching effects on materials research, biological science, and engineering. 

## The SNS Target Building

**The SNS Target Building**

**Proton beam spot size 7 by 21 cm**
**Liquid Mercury target 10 by 40 by 65 cm**
**Two ambient water moderators**
**Two liquid hydrogen cryogenic moderators**
**24 neutron beam lines**

**Notes:**
00-93

## Current Status of the SNS

- Received full construction funding for         FY 2001 ($278M)
- Finished site excavation (moved 1.3 million cubic yards of earth)
- Completed preliminary designs for all buildings, accelerator components, and initial instrumentation

- Building construction begun
- Instrument Development Teams in place for 12 instruments
- On schedule for project completion in 2006

## SNS after completion

## Neutrino Production at SNS

**Hg**

******+**

******-**

- Capture

**99.6%**

******+**

********

********

********

******e**

********

******e**

******-**

- Capture

- e+

- e-

**94%**

**0.098**

**0.061**

**p**

## SNS is a Unique Neutrino Source

- The SNS will produce ~1015 x s-1  in 60Hz pulses from decay of stopped pions
- The most intense pulsed, intermediate energy neutrino source in the world!
- The pulse structure:
- drastically reduces backgrounds from cosmic rays
- allows separation of **from* * ̄* **and *e* *
- Spectra of *,*  ̄**and e* *well known
- Flux of e severely suppressed:
-  ̄e* */  ̄* ** *3 x10-4

## Stopped Pion Neutrino Energy Spectra

- Normalized spectra
- N(e) = ( 12 / W4) E2  ( W - E )
- N() = ( 6 / W4) E2  ( W - 2 / 3 E )
- W=52.83 MeV
-  is monoenergetic at ~ 30 MeV

**Neutrinos from SNS are in the same energy range as neutrinos from Supernovae**** **

**Supernovae**

## Energy and time spectra of neutrinos from SNS

**Energy**

**Time**

## ORLaND

- Oak Ridge Laboratory for Neutrino Detectors

## Large Detector Collaboration Member Institutions

- Carleton University
- Drexel University
- Duke University
- Embry Riddle Aeronautical University
- Institute for Theoretical and Experimental Physics
- Jefferson Laboratory
- Kent State University
- Los Alamos National Laboratory
- Louisiana State University
- North Carolina State University
- Oak Ridge Associated Universities
- Oak Ridge National Laboratory
- Ohio State University

**SNS/ORNL**
**Southern University, Baton Rouge**
**Southern University, New Orleans**
**Tel Aviv University**
**TUNL Laboratory**
**University of Alabama**
**University of California, Los Angeles**
**University of California, Riverside**
**University of Mississippi**
**University of Pennsylvania**
**University of South Carolina**
**University of Tennessee, Knoxville**
**Valparaiso University**
**Virginia Tech**

## ORLaND Bunker

** ****Large enough to accommodate one 2 kton detector and 5-6 ~100 ton detectors**
**Designed to be located in close proximity to the SNS target **
**Has 30 meters of water equivalent of overburden to reduce cosmic rays flux**
**Has independent access tunnel**

## Proposed bunker location is at 90 degrees to the proton beam, on the north side of the target hall

**Proposed bunker location is at 90 degrees to the proton beam, on the north side of the target hall**

## ORLaND Large Detector

**Large 2 kt cylindrical vessel with build in veto system and passive absorber between veto and main tank**
**~5000 13” PMTs**
**For dilute Liq.Scin ~ 35 Ph.e./MeV, ~15 cm space resolution.**
**Capability to put acrylic sphere filled with heavy water.**

**13” Hamamatsu PMT**
**Rise time 6 nsec**
**TTS ~ 2.4 nsec**
**For 1 ph.e. P/V ~ 3.5**
**Dark counts 8 kHz**
**Gain 1********10****7**** at 2000 kV**

## ORLaND Large Detector

**Two options under consideration**
**(or both)**

**Water-Cherenkov detector**
******-d disintegration  (calibration of SNO) **
******-O interaction (SK and SN)**
******-e scattering (calibration of SK)**
**Neutrino Oscillations ?**
**Search for strangeness in nuclei?**

**Dilute Scintillaltor Detector**
**Neutrino Oscillations**
**Neutrino-Electron Scattering**
**Measurement of  electro-weak angle**
**Neutrino magnetic moment**
**Neutrino-Carbon interactions**

## Search for Neutrino Oscillations e appearance mode

**If LSND result confirmed – improve measurement of mixing parameters, and accurately distinguish between ****************e**** ****and**** ******e****e **modes**.

**If LSND result is not confirmed, explore mixing parameters in the regions of interest for Big Bang Nucleosynthesis and Supernovae dynamics.**

***	******dT***** ****	**** ****	**********	*****E************ *****	**** *****E************ ***

*** ******=  ******	***[*g****iL****** + ****g****R  *****(1 –       )****2***** - ****g****iL ****g****R******	****** ***]

**2**

**2**

**2**

***	******d*********(**********i****)**** ****	**** ****	****2*****G******F ******m******e*****	**** *****T*****	**** *****m******e***** *****T***

***	******dT***** ****	**** ****	**********	*****E************ *****	**** *****E*********

**2**

*** ******=  ******	***[*g****R****** + ****g****iL  *****(1 –       )****2***** - ****g****iL ****g****R******	****** ***]

**2**

**2**

**2**

**and**

*	**g****R***** ****	****=****	****Sin**2** ********w***	**  **	**g****eL*****= 1⁄2 + Sin**2** ********w***	**	**g**********L***** = -1⁄2 +Sin**2******w**

**2**

**If neutrino has magnetic moment**

- EM(E)=f2r02[T/E-ln(T/E)-1]
- Where:
- r02 = 2.8210-13 cm
- f is the ratio of neutrino magnetic moment to electron Bohr magneton

******e****-  ****Scattering**

##  e- Scattering (continued)

***R***** =**** **

**Integrate over T:**

***R***** =**** **

**3/4 - 3 sin**2** ********w**** + 4 (sin**2 ******w****)****2**** **
**1 + 2 sin**2** ********w ****+ 8 (sin**2 ******w****)****2**** **

**(*****************e *****)**
*** ***(***********e************e *****) + ***** ***(*****************e *****)**

**Sin****2 ********W****(Q****2****)**

**Neutrino magnetic moment**

## +

**The first accurate measurement of this interference,**
**and another stringent test of the Standard Model**

**e****-**

**e****-**

****

****

**Z****0**

**e****-**

**e****-**

****

****

**W******

**+**

**M**** = ****M****NC**** +****M****CC**

## 16O(e,e-)16F

**16****O(********e****,e****-****)****16****F**

- LARGE CERENKOV DETECTOR** **
**Fiducial vol. 1472 m****3**** of water N ~ 4.9********10****31********16****O**
- Event rates
**For 30% efficiency ~ 12300 events per year**
- Haxton, PRD 36, 2283 (1987)
**<********>=8.84********10****-42**** cm****2**** DAR spectrum**

**********e**** (degrees)**

**d********/d******** (10****-43**** cm****2****/sr)**

**SN T = 4 MeV**

**SN T = 10 MeV**

**********e**** (degrees)**

**d********/d******** (10****-43**** cm****2****/sr)**

**SN T = 10 MeV**

## 16O(x,x`n)15O

- Use Large Size Cerenkov Detector
- N ~ 4.91031 of 16O
- Event rates:
- For 16O(x,x`n)15O R ~ 4200 y-1
- For 16O(x,x`(n or p))15X R ~ 21500 y-1
- Can some compound of Gd be added to boost neutron detection?
- Langanke, Vogel, and Kolbe, Phys.Rev.Lett. 76, 2629 (1996) (SN spectrum)
- Kolbe, Langanke, Thielemann, Eur.Phys.J. A3, 389 (1996) DAR spectrum.
- <>=910-43 cm2 DAR spectrum

## d(e,e-)pp

- SNOINO
- 30 ton Cerenkov Detector
- (D2O is expensive, 30 ton can be borrowed)
- 30 tons of D2O is contained in an acrylic cylinder inside a large water cerenkov detector
- Event rate
- R(detected) ~ 2800 y-1 30 ton-1
- <>=5.410-41 cm2 DAR spectrum
- Kubodera and Myhrer in “Proceedings of the Accelerator Production of Tritium Symposium”, May 14,15, 1996, Columbia S.C. eds. F.T.Avignone and T.A.Gabriel, World Scientific p.148

## Calibrating the Sun

-  *p* + *p*      d + e+ + ****** e (99.75% solar energy)
- Can be deduced from:  ******e + d      *p* + *p *+ e-
- Theory: Kubodera + Nozawa  *** = 52 x 10**-42** cm**2*
- Experiment: Lampf E31  *** = (53 ± 18) x 10**-42** cm**2 **(34%)*
- Measurement to a few % needed

- Calibrating SNO

**CC:  ********e**** + d = p + p + e****-**

**NC:  ********x**** + d = p + n**

**e****-**

**p p**

**n p**

******e**

******x**

******x**

**n p**

**n p**

**Z****0**

**W******

## Reaction Cross section for DAR neutrinos

- ee-  e’e-
- e-  ’e-
- e-  ’e-
- e12C  12Ngse-
- e12C  e12C*
- 12C  12C*
- 12C  12C*
- ep  ne+

**0.0297********10****-41**** cm****2**
**0.0050********10****-41**** cm****2**
**0.0048********10****-41**** cm****2**
**0.92********10****-41**** cm****2**
**0.45********10****-41**** cm****2**
**0.27********10****-41**** cm****2**
**0.55********10****-41**** cm****2**
**7.2********10****-41**** cm****2**

**For 2 kt detector at 50 meters from target we will have ~ 300 neutrino interactions per day!!!**

## Neutrino Nucleus Cross Sections at ORLaND

**A**

**Accuracy of cross section measurement**

**d**

**C**

**Fe**

**Existing data**

**Proposed for ORLaND**

**Large detector C, d, O**
**Smaller detectors: Cl, Fe, I, Pb,..**

## Recent Activities

**May 2000 –Workshop at OAK Ridge “Scientific Opportunities at ORLaND”**
**August-September discussions of ORLaND scientific program at Seattle and Oakland pre-town and town meetings.**
**Fall 2000 presentations for DOE and NSF**
**2000-2001 continue integration of ORLaND design into the SNS construction: zero impact on SNS cost or schedule.**
**Working on proposals for DOE, NSF. **

## CONCLUSION

- SNS is a unique intermediate energy neutrino source
- We propose to build ORLaND, an underground neutrino facility adjacent the the SNS target hall.
- The facility will be large enough to host one large 2 kt detector and several smaller (~100 ton) detectors
- Such a facility will enable:
- search for neutrinos oscillations
- precise measurement of elastic e scattering
- Flux calibration
- Neutrino magnetic moment
- Weak mixing angle at small Q2
- measurements of N interactions in the energy scale relevant to solar physics and astrophysics