pnpi-ill-pti collaboration at ill reactor in grenoble and at wwr-m reactor in gatchina

PNPI-ILL-PTI collaboration at ILL reactor in Grenoble

and at WWR-M reactor in Gatchina

Present status and

future prospects of “Gatchina double chamber EDM spectrometer”

Serebrov A.P. PNPI 26 June 2012

History of nEDM measurements. Results and prospects of PNPI-ILL-PTI collaboration

1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 202010-28

10-27

10-26

10-25

10-24

10-23

10-22

10-21

10-20

- Minimal SUSY

- Weinberg Multi-Higgs

- Left-Right Symm.

- Electromagnetic

TheoreticalPrediction:

MIT-BNL ORNL-Harvard ORNL-ILL... ILL-Sussex-RAL... PNPI

Neu

tron

ED

M E

xper

imen

tal l

imit

(e·c

m)

Year

Present limit Estimation of accuracy at ILL

Estimations of accuracy at super UCN source in Gatchina

Cosmology

4

!

!!


1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 202010-28

10-27

10-26

10-25

10-24

10-23

10-22

10-21

10-20

- Minimal SUSY


- Left-Right Symm.

- Electromagnetic



Neu

tron

ED

M E

xper

imen

tal l

imit

(e·c

m)

Year



Cosmology

6

!

!!

7

ILL UCN facilities - PF2 MAM (in the past)

platform(iron)

NESSIE vacuum vessel

8

The allocation scheme of the multi-chamber EDM spectrometer at PF2 UCN facility

9

Installation of non-magnetic platform

First experiment on the non-magnetic platform

mirror particles

particles

mirror antiparticles

antiparticles

History of mirror ideas

mirror world

mirror antiworld

world

antiworld

Coexistence is possible, transitions are complicated

annihilation!!

Coexistence is not possible

coexistenceL

R

L

R

610-10=?

Review (259 references)hep-ph/0606202 v2 Dec 2006

Physics-Uspekhi 50 (2007) 380

How to observe n-n transitions

Energy states of ordinary and mirror neutron are degenerated when magnetic field H=0, and transitions are possible. Due to magnetic field energy states of neutron can be shifted and transitions to mirror state will be suppressed.

The evolution of nonrelativistic n-n system in the external magnetic field B is described by the effective Hamiltonian :

2

2

( )2 2

2 2

Pm i B V m

mHP

m m i Vm

H=0 (H<10-4 Gauss) H0 (H0.2 Gauss)

n

13

Assembling of magnetic shielding and vacuum of EDM spectrometer

14

Preparation of n n experiment at ILL

15

Assembling on the platform

17

Study of linear effect (H+/H-) with vertical magnetic field

/H H

R N N

1r R

46.4 2.4 10r

2 2.56

0 2000 4000 6000 8000 10000 12000 14000

-0,006

-0,004

-0,002

0,000

0,002

0,004

0,006

Data: EFF25NOV_BModel: y = b+cx Chi 2/DoF = 2.55962R 2 = 3.3307E-16

b 0.00064 ±0.00024c 0 ±0

26Nov 28Nov 30Nov 2Dec 4Dec 6Dec

r-eff

ect

Time (min)

Go back to EDM

19

Assembly of double-chamber EDM spectrometer in summer 2008 in the interval between reactor cycles

20

August 2008. Completion of main part of assembly.

21

September 2008 - Assembly and testing of detectors, magnetometers and electronics. October 2008 - Start of the first measurements with the neutrons

0,0 0,5 1,0 1,5 2,0 2,50,0

2,5

5,0

7,5

10,0

12,5

Turbine exit

EDM sp. entrance

Calculation

AE3/2

[c

m3 ]

Ec[m]

=7.5 cm-3

22

Direct measurements of UCN density in the EDM spectrometer entrance and at the UCN turbine exit

st fill st emp0exp 2

st

( )( )N

V

Resonance curve of the double-chamber EDM spectrometer, T(stor)=20s

23

53.0 53.2 53.4 53.6 53.8 54.0 54.2

2000

3000

4000

5000

6000

7000

8000

Co

un

ts p

er

cyc

le

Frequency [Hz]

Det1+Det2

Resonance curve of the double-chamber EDM spectrometer, T(stor)=20s

24

53.50 53.55 53.60 53.65 53.70 53.75 53.80 53.85 53.90

2000

3000

4000

5000

6000

7000

8000

Co

un

ts p

er

cycle

Frequency [Hz]

Phase 00

Phase 1800

First estimation of EDM sensitivity (1,5 – 2,0) ∙ 10-25 e∙cm/day

for 20kv/cm , T (stor) = 60s, 4 detectors

25

Possible long-range interaction (axion-like interaction) between nucleons

r(1) (2)s sg g

V(r) e4 r

r(1) (2) 2s p 2

2

r 1 1V(r) g g e

8 M r r

(1)sg (2)

sg

1 2 1 2

(1)sg (2)

5 pi g

A.A. Anselm JETP Lett.v36 N2 (1982)

J.E. Moody and Frank WilczekPhys. Rev. D v30 N1 (1984)

26

Direct experimental limits for gSgP and “axion window” of mass or distance of interaction

Am c

32 10 cm 2 cm

27

Additional effective magnetic field in EDM spectrometer

z

5S P n effV(z) 5.2 10 eV / cm cm e g g H

z

z516S P

eff S Pn

5.2 10 e g gH 8.7 10 G / cm cm g g e

12n 6 10 eV / G

UCN depolarization on vertical wallsA. Serebrov(arxiv:0902.1056)

shift of resonances on horizontal wallsO. Zimmer(arxiv:0810.3215)

28

Measurement of UCN depolarization in EDM spectrometer

0 10 20 30 40 50 60 70 80 900,50

0,55

0,60

0,65

0,70

0,75

0,80

Data: DounledH0_P2 Chi 2/DoF= 1.3572R 2 = 0.98598

A1 0.7873 ±0.00147t1 697.755±27.418

Data: H0_P2 Chi 2/DoF= 1.27029R 2 = 0.9779

A1 0.7606 ±0.00168t1 789.846±40.291

Data: DounledH0_P1 Chi 2/DoF= 0.36793R 2 = 0.9918 A1 0.774 ±0.0019 t1 768.162 ±44.13

Data: H0_P1 Chi 2/DoF= 1.69316R 2 = 0.95239 A1 0.757 ±0.00217t1 784.282 ±51.57

Pol

ariz

atio

n

Storage time

H0 Upper chamber double H0 Upper chamber H0 Lower chamber double H0 Lower chamber

29

Measurement of resonance shift at the change of direction of magnetic field in EDM spectrometer

119,0 119,5 120,0 120,5 121,0 121,5 122,01000

1500

2000

2500

3000

3500

4000

4500

5000

5500

D1 D2

Div.coeff.

magnetic field down

30

119,0 119,5 120,0 120,5 121,0 121,5 122,0

1000

1500

2000

2500

3000

3500

4000

4500

Div.coeff

D1 D2

magnetic field up

Measurement of resonance shift at the change of direction of magnetic field in EDM spectrometer

31

Result of measurements (JETP Letters, 2010, Vol. 91, no. 1, pp. 6-10)

.

10-4 10-3 10-2 10-1 100 101 102

10-29

10-27

10-25

10-23

10-21

10-19

10-17

10-15

10-13

[12]

54

1

2

CDM [13]SN1987A [13]

mA, eV

g Sg P

range , cm

3

10-1 10-2 10-3 10-4 10-5 10-6

6

1 – UCN depolarization (this work); 2 – shift of resonance (this work); 3 – gravitational levels [5]; 4 – [12]; 5 – astrophysical restriction of axion mass [13]; 6 – cosmological restriction of axion mass in model of cold dark matter [13]. On the upper horizontal axis the mass range of intermediate boson (axion) is shown in correspondence with formula Am c

Again go back to EDM

34

Preparation of Cs-magnetometers at PTI

8 (4x2)Cs-magnetometers inside EDM spectrometer

35

System of optical pumping with light guides

36

37

Stabilization of magnetic field during resonance measurements (system of stabilization of resonance conditions + feedback by means of current coils)

quiet magnetic situation

12:00 14:00 16:00 18:00 20:00 22:001843

1844

1845

1846

1847

1848

1849

1850

1851

Mag

neti

c f

ield

[n

T]

Time

Up Down Mean

Stabilization of magnetic field during resonance measurements (system of stabilization of resonance conditions + feedback by means of current coils)

38

full day tests of bridge crane

12:00 14:00 16:00 18:00 20:00 22:00

1843

1844

1845

1846

1847

1848

1849

1850

Mag

neti

c f

ield

[n

T]

Time

Up Down Mean

The influence of external magnetic fluctuations on stability of resonance conditions in a spectrometer.

(factor of stabilization by mean of 8 Cs-magnetometers is about 10 – 15 times)

39

a)FM is the average frequency measured by means of eight Cs magnetometers;

b) FN is the frequency measured by the additional Cs magnetometers in working volume;

Difference FN – FM.

0 20 40 60 80 100

-0.306

-0.305

-0.304

crane operation

Number of measurement

F [H

z] 1.3*10-4

54.071

54.072

54.073

FN [H

z]

54.375

54.376

54.377

1.7*10-3

FM

[Hz]

For reduction of UCN losses the neutron guides and storage chambers (glass-ceramics rings and electrodes) were sent to PNPI where their surfaces were cleaned and freshly coated with 58Ni-Mo and BeO, Be, respectively.

PNPI installations for coating of neutron guides and storage chamber.

41

Coating facilities at PNPI (installation for coating of flat surface of UCN guides and electrodes

(Ni58Mo, Be) and cylindrical surface of UCN trap (BeO)

Near installation A.Kharitonov, E.Siber, O.Rozhnovrotating table

ion gun sputtering magnetron

42

Coating facilities at PNPI (installation for coating of cylindrical UCN guides inside (Ni58Mo, Be))

Near installation M.Lasakov, A.Vasiliev

moveable tube support magnetron ion gun

Glass ceramics rings (insulators) and new entrance guide after coating by BeO and 58Ni-Mo

44

UCN guide with a big diameter (replica technology)

Installation for coating of Ni58Mo on the float glass foil after separation

from glass(size 700x470 mm2)

preparation of a UCN guide

UCN guides of different diameters

45

additional coils

Electronics for magnetic field generation

J Vmain solenoid

J/J = 2.510-7 ≈ 0.5 pT

J/J = 110-7 ≈ 0.2 pT

J/J = 2.510-7 ≈ 0.5 pT

The recent measurement of EDM sensitivity

Direct measurement of sensitivity of EDM spectrometer with UCN density 3-4 ucn/cm3 (MAM position) with electric field 10 kV/cm and

T(hold) = 65 s

47

0 5 10 15 20

-500

-400

-300

-200

-100

0

100

200

300

400Dt=(16±14)*10-25e*cm

Db=(24±16)*10-25 e*cm

D=-(4±6)*10-25e*cm

ED

M [

10

-25 e

*cm

]

Time of measurement [hours]

Dt Db D

δDedm ~ 5 10∙ -25 e cm/day∙

New result with HV(+_)175kV/ 8.7cm = 20kV/cm

Corrected measurement of sensitivity of EDM spectrometer with UCN density 3-4 ucn/cm3 (MAM position) with new

electric field 20 kV/cm and T(hold) = 65 s

ρucn at entrace ~ 3-4 ucn/cm3,

δDedm ~ 2.5 10∙ -25 e cm/day∙

Upper limit of sensitivity : 2.5 10∙ -26 e cm/100 days∙


1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 202010-28

10-27

10-26

10-25

10-24

10-23

10-22

10-21

10-20

- Minimal SUSY


- Left-Right Symm.

- Electromagnetic



Neu

tron

ED

M E

xper

imen

tal l

imit

(e·c

m)

Year



Cosmology

50

!

!!

2011 2012 2013 2014 2015 2016 2017 201810-28

10-27

10-26

10-25

Neutron E

DM

Exp

erim

enta

l lim

it, e

·cm

Year

double-chamber @ ILL MAM position

PNPI-ILL-PTI collaborationProspects to increase sensitivity of EDM measurements

Gatchina EDM spectrometer 1975

Gatchina EDM spectrometer at ILL

PF2 position EDM

52

EDM spectrometer on the position EDM PF2(legs of platform have to be cut ( 1.3 m))

53

Magnetic shielding

HV

Electronic equipment

UCN from turbine

upstairs

detectors

Polarizer

analyzers

GAIN FACTOR IN UCN DENSITY is 3 - 4 times.

Test beam

EDM sensitivity at PF2 position “EDM”

2013 - 2014. New position at PF2 (EDM instead of MAM) Factor in UCN density is about 3 – 4 times in respect to MAM position.

ρucn at entrace ~ 20 ucn/cm3, δDedm ~ 1 10∙ -25

e cm/day∙ Upper limit of sensitivity : 1 10∙ -26 e cm/100 ∙

days

2011 2012 2013 2014 2015 2016 2017 201810-28

10-27

10-26

10-25

double-chamber @ ILL EDM position

Neutron E

DM

Exp

erim

enta

l lim

it, e

·cm

Year





EDM sensitivity at new position H172B, UCN source with superfluid He at ILL.

2015. New position at H172B, UCN source with superfluid He at ILL. Factor in UCN density is about 10 times in respect to PF2 EDM position. ρucn at entrace ~ 200 ucn/cm3,

δDedm ~ 3.5 10∙ -26 e cm/day∙

Upper limit of sensitivity : 3.5 10∙ -27 e cm/100 days∙

2011 2012 2013 2014 2015 2016 2017 201810-28

10-27

10-26

10-25

double-chamber @ ILL UCN source with superfluid He


Neutron E

DM

Exp

erim

enta

l lim

it, e

·cm

Year





PNPI-ILL-PTI collaboration at Gatchina UCN supersource

at PNPI WWR-M reactor

future prospects

New facilities at PNPI, UCN source with superfluid He.

2016. New facilities at PNPI, UCN source with superfluid He. Factor in UCN density is about 60 times with respect to H172B ILL facility.

ρucn at entrace ~ 12000 ucn/cm3, δDedm ~ 5 10∙ -27 e cm/day∙

Upper limit of sensitivity : 5 10∙ -28 e cm/100 day∙2017 -2018. New facilities at PNPI, UCN source with

superfluid He. Multichamber EDM spectrometer. ρucn at entrace ~ 12000 ucn/cm3, δDedm ~ 3 10∙ -27 e cm/day∙

Upper limit of sensitivity : 3 10∙ -28 e cm/100 day∙

2011 2012 2013 2014 2015 2016 2017 201810-28

10-27

10-26

10-25

double-chamber @ PNPI super UCN source



Neutron E

DM

Exp

erim

enta

l lim

it, e

·cm

Year





2011 2012 2013 2014 2015 2016 2017 201810-28

10-27

10-26

10-25

multi-chamber @ PNPI super UCN source




Neutron E

DM

Exp

erim

enta

l lim

it, e

·cm

Year





62

Project of ultracold and cold neutron source

with superfluid helium at WWR-M reactor

Vertical cross section of WWR-M reactor.1 – reactor core, 2 – reactor tank, 3 – concrete protection, 4 – chamber above the reactor, 5 – horizontal channel, 6 – thermal column, 7 – vertical channel.

Cross section of WWR-M reactor

63

Thermal column of WWR-M reactor

Idea

UCNs are generated in helium from cold neutrons of 9Ǻ wavelength (12 K energy). It is correspond with phonon energy: cold neutron enegizes phonon, practically stops and becomes an ultracold one. UCN can “lives” in superfluid helium for tens or hundreds of seconds until a phonon be captured. Cold neutrons (9Ǻ) penetrate through the wall of a trap, but ultracold neutrons (500Ǻ) are reflected, that is why UCN can be accumulated up to the density defined by the time of storage in the trap filled with superfluid helium.

64

CN =9 Å, T=12 K

UCN =500 Å, T=10-3 K

phonon

He Т=1.2 К

Pb Т=300 К

Ф=1014 n/(cm2s)Q=15 MW

Al, QAl=13 W

C, QC=700 W

Pb, QPb=15 кW

19 W

65

LD2 Т=20 К

C Т=300 К

LD2, QLD2+Al=100 W

MCNP neutron flux calculation results and heat generation in thermal column of WWR-M reactor at 15

MW

ucn=104 сm-3 (=10 s)Ф=4.5∙1012 n/(сm2s)Ф(=9 А)=3 10∙ 10 n/(сm2sA)QHe=6 W

Cryogenic scheme of UCN source with superfluid He

1 – He II cell; 2 – UCN neutron guide, 3 – CN neutron guide, 4 – He II supply pipe, 5 – lower bath @ 1.2 К, 6 – intermediate bath @ 1.2 К, 7 –3Не filter, 8 – level sensor, 9 – upper bath @ 4.2 К, 10 – helium supply valve, 11 – level sensor, 12 – vacuum pipe (gravitation trap for UCN), 13 – vacuum pipe for lower bath, 14 – vacuum pipe for intermediate bath, 15 – main vacuum manifold, 16 – UCN neutron guide membrane, 17 – CN neutron guide membrane, 18 – thermal shield @ 20 К, 19 – vacuum jacket, 20 – UCN outer neutron guide, 21 – CN outer neutron guide, 22 –helium supply at temperature of 4.2 К, 23 – pipe for helium vapour removal, 24 – helium supply for thermal shield 18, 25 – helium removal from thermal shield 18, 26 – pumping of vacuum jacket.

UCN

CN

66

67

а – Pb shielding mounting; b – graphite block mounting; c – mounting of cryostat, UCN superconductive polarizer and UCN switchboard; d – mounting of biological shielding.

а b

c d

Installation of UCN source on WWR-M reactor

hall of thermal neutrons hall of cold neutrons

hall of very cold neutrons

hall of ultracold neutrons

Ultracold and cold neutron source at WWR-M reactor with neutron guide halls

68

Demounting of old equipments

Demounting of old equipments is finished

General view with new equipment

71

Helium refrigerator 15 K, 3000 Watts

72

Helium liquefier50 l/h

Gas system

73

74

Pumping system of helium

High pressure compressors

Water cooling system

Gas Storage System

Preparation of non-standard equipment

Vacuum test of full-scale model of UCN source

Cryogenic test of full-scale model of UCN source

Manufacturing of cryostat for superfluid helium at 1.2 K

Manufacturing of He heating system

Vacuum test of He heater

Manufacturing of He pumping tubes

2011 2012 2013 2014 2015 2016 2017 201810-28

10-27

10-26

10-25

multi-chamber @ PNPI super UCN source




Neutron E

DM

Exp

erim

enta

l lim

it, e

·cm

Year


Instead of summary

Gatchina EDM spectrometer

1975


Thank you for attention

США (ORNL) Швейцария (PSI)

Франция (ILL) Япония-Канада (KEK-RCNP-TRIUMF)

Проекты по измерению ЭДМ нейтрона в мире

89

90

UCN density

maximal density inside closed source

density in experimental trap with volume 35 l

density in experimental trap with volume 350 l

1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 201510-7

10-6

10-5

10-4

10-3

10-2

10-1

100

101

102

103

104

105

[13]

[8]

[6][5]

[4][12]

[15-16]

present

[3] [9]

[10]

first testexperimentwith SD

2

PNPI

SD2 Mainz

project [17]

projects

ILLILL

first test experimentswith superfluid He

test experiment

projectSD

2 in pulse mode

SD2 pulse mode

SD2 reactor

PSI-PNPIPNPI

PNPI

LANL-PNPI

SRIAR

ILL

ILL

IAETUM

IAE

J INR

PNPIPNPI

PNPI

PNPIPNPI

PNPI

UC

N d

ensi

ty, cm

-3

years

Comparison of expected UCN density with UCN density of present sources

UCN density (сm-3) Gain factor

Present project 104

ILL (turbine source) 10 103

91

I.Ya. Pomeranchuk “Selected works”

Neutron scattering in liquid helium

UCN source based on superfluid He-IIR. Golub, J.M. Pendlebury, Phys. Lett. A 62 (1977) 337

Ebeg=12 K EUCN10-3 K

=9 Å

92

About neutron scattering with energy a few degree in fluid Helium II

The scattering of slow neutron in He-II is considered. It is shown that the scattering is a negligible small at the temperature below than temperature of critical point.

H.Yoshiki experiment at ILLPhys. Lett. A 308 (2003) 67-74

time, s

neut

ron

coun

tne

utro

n co

unt

wavelength, A

stor

age

time,

s

temperature, K

UCN density in the source =СФ(=9Å)=2.7107 n/(сm2sА)С – UCN generation (0.90.1) n/(сm3s)- storage time in the source10 сm-3

93

94

Storage time of UCN in He-II (results of experiment)de

tect

or c

ount

s

holding time, s

temperature, K

stor

age

time,

s

10

T=1.16 K

93 s (T=0.49 K)

1.3 K

1.0 K

103

102

1000 s

100 s

10 s

20 s30 s

70 s

Process of capture and accumulation of DM in gravitational field of Earth

Galaxy flux of dark matter

thermalisation inside the Earth

galo due to particles with kinetic energy less than potential energy

escape from gravitational field of Earth for particles with kinetic energy more than potential energy

Density on the Earth surface forlong-range interacting DM and WIMPs DM

M.Onegin, A.Serebrov, O.Zherebtsov. arXiv:1109.3391 [nucl-ex] 15 September

factor of increasing for

long-range DM ~ 106factor of increasing for

WIMPs DM ~ 102

Possible scheme of DM motion around Earth

Moon EarthSun

Assumption of predicted behaviour of the dark matter captured by the system Earth-Moon

Treatment of experimental results with time period 24 hours 50 minutes

29 Aug – 22 Sep 2007 10 Nov – 03 Dec 2007

(/)24h50m =(-1.9±1.0)10-4 (/)24h50m =(-1.4±1.3)10-4

(/)24h50m =(-1.7±0.8)10-4

0 2 4 6 8 10 12 14 16 18 20 22 24 260,2580

0,2585

0,2590

0,2595

0,2600

0,2605

0,2610

(D1 e

+ D

2 e) / M

f

time, h

29 aug - 22 sep holding 300 sModel mirr (User)

Equationy = y0+A*sin(pi*(x-xc)/w)

Reduced Chi-Sqr

1,53168

Adj. R-Square 0,06672

Value Standard Error

F

y0 0,25945 1,87832E-5

A -5,07259E-5 2,65748E-5

xc 13,58749 2,06928

w 12,42058 0

0 2 4 6 8 10 12 14 16 18 20 22 24 260,2850

0,2855

0,2860

0,2865

0,2870

0,2875

0,2880

(D1

e + D

2e)

/ M

f

10 nov - 3 dec holding 300 s

time, h

Model mirr (User)

Equationy = y0+A*sin(pi*(x-xc)/w)

Reduced Chi-Sqr

2,07383

Adj. R-Square -0,04276

Value Standard Error

B

y0 0,28682 2,68501E-5

A -3,91642E-5 3,80974E-5

xc -1,66311 3,82023

w 12,42058 0

Constraints for parameters and from: neutron lifetime experiments (UCN-1), kcapt=1; UCN low energy upscattering (UCN-2), kcapt=1; experiments for matter-matter interaction (M-M).

And prediction for and from DAMA experiment.

A

r

N n DM

rq n DM

r

OM DM n DM

G m M(r) e

r

G m M(r) e

r

g g m M(r) e

r

Conclusion about daily variation of storage time (200 s)

1. Experimental limit for variation of storage time (200 s) with time period 24 hours is:

(/)24h ≤210-4 (90% C.L.)

2. Experimental limit for variation of storage time (200 s) with time period 24 hours 50 minutes (lunar day) is:

(/)24h50m ≤310-4 (90% C.L.)

A.Serebrov, O. Zherebtsov. Astronomy Letters 37 (2011) 181, arXiv:1004.2981v2

If one assumes that in the DAMA experiment the signal of long range dark matter has been observed, it is possible to set restriction on the upper limit for density of long range dark matter on the Earth: g/сm-3, using the experimental results with UCN.

Conclusion about density of low energy dark matter

with long range forces on the Earth

E-surface 13DM 6.6 10

E surface12DM

capt gal.DM

k 1.3 10

pnpi-ill-pti collaboration at ill reactor in grenoble and at wwr-m reactor in gatchina

Documents

vacuum of edm spectrometer

edm spectrometermagnetic

edm spectrometer entrance

magnetic field h

multichamber edm spectrometer

vertical magnetic field

estimation of edm sensitivity

external magnetic field