mariano carmona gallardo grupo de física nuclear experimental instituto de estructura de la materia...

Mariano Carmona Gallardo

Grupo de Física Nuclear ExperimentalInstituto de Estructura de la Materia

CSIC-Madrid

O. Tengblad1, B.S. Nara Singh2, M. Hass3 , M. Alcorta1, M.J.G. Borge1, J.A. Briz1, M.Cubero1, C. Cruz1, R. Dominguez-Reyes1, B. Fulton2, H. Fynbo5, N. Gordillo6, G. Haquin4 , Y. Nir-El4, V. Kumar3, A. Maira6, A. Muñoz6, A. Perea1,Z. Yungreis4

1Intituto de Estructura de la Materia-CSIC, Madrid, Spain2University of York, York, UK3Weizmann Institute of Science, Rehovot, Israel4Soreq Research Center, Yavne, Israel5Aarhus University, Aarhus, Denmark6Centro de Microanálisis de Materiales-UAM, Madrid, Spain

WORKSHOP ON REACTIONS OF ASTROPHYSICAL

INTEREST (EUROGENESIS )

April 2011

ASTROPHYSICAL FACTOR OF 3He(4He,γ)7Be USING ACTIVATION METHOD

OUTLINE

M. Carmona-Gallardo MADRID April 2011Astrophysical Factor of 3He(4He,γ)7Be

1. MOTIVATION FOR 3He(4He,γ)7Be EXPERIMENT

2. EXPERIMENTAL MEASUREMENT OF(E) FOR 3He(4He,γ)7Be

3. CMAM FACILITY

4. SET-UP

5. EXPERIMENTAL MEASUREMENTS: CONSIDERATIONS & ESTIMATIONS

6. OBSERVABLES MEASUREMENTS

7. RESULTS

8. ONGOING AND FUTURE WORK

OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP

CONSIDERATIONS & ESTIMATIONS

OBSERVABLES

RESULTS

ONGOING AND FUTURE WORK

MOTIVATION


OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


S34(0)= 0.56 ± 0.02 (exp) ± 0.02 (model) keV·b compared with the previous value (0.53 ± 0.05) keV·b

(The analysis is based on all activation data plus ERNA recoil data)

Solar fusion cross sections II: arXiv:1004.2318v3

1. Direct detection of 7Be recoils produced during the reaction. (European Recoil Separator for Nuclear Astrophysics)

2. Detection of direct gamma reaction produced during the reaction: DC 429 keV, 429 keV 0

3. Detection of gamma radiation of 478 kev from de-excitation of 7Li after decay of 7Be:

T1/2=53.350 (50) days.

EXPERIMENTAL MEASUREMENT OF(E) FOR 4He(3He,)7Be

e+

7Be7Li

Proton

Neutron

4He

3He

MADRID April 2011Astrophysical Factor of 3He(4He,γ)7Be M. Carmona-Gallardo

Activation MethodDirect detection of 7Be or prompt radiation detection

OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


GAS TARGET OF 4He AND BEAM OF 3He+ PARTICLE

BEAM ENERGIES: 2.3, 3.2, 4, 4.4, 4.8 5.3 MeV

THE GAS CHAMBER MUST BE ELECTRICALLY INSULATED FROM THE LINE, SEPARATED BY A OIL

FOIL MUST KEEP THE PRESSURE DIFFERENCES BETWEEN LINE AND CHAMBER

AS THIN SCATTERING-FOIL AS POSSIBLE WHILE STILL RESISTANT TO HEAT FROM THE BEAM NI FOIL 1 m THICK

GAS SYSTEM TO GUARANTEE CONSTANT PRESSURE IN THE REACTION CHAMBER

EXPRESION :

·4d

targetin the particles ofNumber tN

particleincident ofNumber pN

dd

dtNpN produced Be7

lab

lab

lab

M. Carmona-Gallardo

EXPERIMENTAL MEASUREMENT OFs(E) FOR 4He(3He,)7Be II

OBSERVABLES: Nº ion 7Be, nº of incident 3He+ ion, nº ions 4He in the target

EXPERIMENT IN NOVEMBER 2009

MADRID April 2011Astrophysical Factor of 3He(4He,γ)7Be

OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


M. Carmona-Gallardo

CMAM

• Centro de Microanálisis de Materiales de Madrid (CMAM), at Universidad Autónoma de Madrid

•Seven experimental lines. One line for Experimental Nuclear Physics operated by Grupo de Fisica Nuclear Experimental del IEM-CSIC

•High voltage system Cockcroft-Walton

•Tandem electrostatic accelerator of 5MV

•Two ion sources: Sputtering source

Duoplasmatron source(used during the experiment)

NUCLEAR PHYSICS LINE


OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


EXPERIMENTAL SET-UP

Silicon detector

Collimator

Pressure gauge

4He Gas

Cu catcherNi foil

-180 V suppressor

3He beam

Scattered beam

Insulator

Np (CHARGE INTEGRATION)

Np (MONITORING)

Nt=9.966 ·1018· l·P/(T+T0)7Be recoils

dΩlab

dΩ

dσt

Np

N )(º 7

BeN

MADRID April 2011Astrophysical Factor of 3He(4He,γ)7Be M. Carmona-Gallardo

OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


EXPERIMENTAL SET UP II


OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


M. Carmona-Gallardo Astrophysical Factor of 3He(4He,γ)7Be MADRID April 2011

Catcher electrically connected to the chamber

Suppressor at -100V to avoid escape of e- and loss of current integrations

SRIM and LISE++ used for previous calculations-.

≈1µA (6.2 · 1012 3He/s) ≈3µbar ≈50torr & 300 K

3He(4He,γ)7Be Eγ =429 KeV

· θ ≈ 45º ·Ebeam ≈ 4 MeV / I ≈ 1µA ·tNi ≈ 1 µm / d = 8.9 g/cm3

·Energy-loss in the Ni foil taken into account. Assuming the R.S at the middle of the foil

Ebeam= 4 MeV 26.04 cm Ni foil - Si Energy Loss in Ni foil

θ/2)(sen

1

42E

eZZ

4

1

d

d4

2

0

221

7Be in catcher

Particles mesaured at Si detector same than RS

-100V

C.R.≈ 295 7Be/s

≈4155 3He at 45º

E(3He at Si) ≈ 2.694 MeV

EXPERIMENTAL MEASUREMENTS:CONSIDERATIONS &ESTIMATIONS

OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


Previous and post calibration of Silicon detector with triple alpha and 148Gd sources

Some Parameters: Bias (detector de Si): -100 V Leakage current: 0.48 µA Leak Rate 0.10 torr/h (Very good) Line pressure ≈ 1.1 · 10-6 torr Typical currents 180 - 200 nA

Six catchers with different parameters

MAESTRO: Number of particles which suffer elastic scattering Beam Intensity Energy of Particles Beam energy

C foil used to measure the detector angle precisely. (Z(C) < Z(Ni))

Ni foil thickness measured with an external set up in a vacuum chamber and a Si detector

)1(

cos21

E

E2

2

beam

Si

CM

M. Carmona-Gallardo Astrophysical Factor of 3He(4He,γ)7Be MADRID April 2011

EXPERIMENTAL MEASUREMENTS:CONSIDERATIONS &ESTIMATIONS

OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


27

4 HeNibCM

EEEE

OBSERVABLES MEASUREMENTS

M. Carmona-Gallardo

A) ECM

We assume the reactions take placed at the center of gas target [1][2]

Beam energies with ±20 keV error

Energy loss in the Ni foil and gas target simulated with TRIM

Straggling in Ni foil and Gas target simulated with TRIM negligible•[1] B. S. Nara Singh et al. PRL 93, 262503 (2004)•[2]A.R. Junghans et al. PRL 88, 0411101 (2002)

OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS




M. Carmona-Gallardo

B) 4He: (Nt : number of gas target ions per cm2 ) Assuming ideal gas due to the low pressures we can consider:

Ct TT

PlN

0

1810·66.9


OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


P: gas pressure (Torr)T0 : room temperature (k)l: target length (cm)

Tc temperature correction due to the beam heating measured experimentally using the 1.518 MeV resonance in the 10B(,p)13C. 17K for 500nA @ 2 MeV. [1]

Ebeam (MeV) Pon (Torr) T (K) DISTANCE (catcher-foil)

2.3 54.68±0.21 300.2633 13.95±0.01

3.2 63.77±0.27 309.2261 13.95±0.01

4 50.64±0.02 313.7672 11.63±0.01

4.4 50.66±0.01 316.5130 11.48±0.01

4.8 50.83±0.07 318.4352 11.58±0.01

5.3 56.68±0.29 319.0396 13.95±0.01

[1] B. S. Nara Singh et al. PRL 93, 262503 (2004)


M. Carmona-Gallardo

C) 3He: Charge Integration & Elastic Scattering in the Ni foil


OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


Ebeam (MeV)

INTENSITY (pulses)

NP(charge integration)

(at)

Rutherford spectra

integration

NP(3He with R.s

2.3 4.54E+7 2.834E+16 5.90E+07 2.79E+16

3.2 8.00E+7 4.993E+16 4.93E+07 5.00E+16

4 1.00E+8 7.321E+16 4.33E+07 7.17E+16

4.4 8.37E+7 5.226E+16 2.54E+07 5.16E+16

4.8 5.16E+7 3.224E+16 1.29E+07 3.17E+16

5.3 6.24E+7 3.893E+16 1.27E+07 3.85E+16

M. Carmona-Gallardo

D) 7Be:

E) Complementary measurements

Angle of Silicon DetectorNi foil thickness



~900 cts. After 6 days

OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


M. Carmona-Gallardo

RESULTS

ECM

(KeV)b

)S34(E) (keV·b)

(INTEGRATION)S34(E) (keV·b)

(RUTHERFORD)

903.631 1,872 0.398 0.407

1487.45 2,896 0.304 0.303

2010.64 3,78 0.295 0.304

2256.03 5,075 0.363 0.370

2499.05 5,502 0.367 0.376

2791.21 6,446 0.402 0.410


GOOD AGREEMENT

BETWEEN BOTH TECHNIQUES

OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


M. Carmona-Gallardo

RESULTS COMPARATION WITH PREVIOUS MEASURMENTS


OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


M. Carmona-Gallardo

ONGOING & FURTURE WORK

Try to reduce statistical errors with new activation method measurements

New strategy as we only have one low HpGe station

Calculate all errors

Use different theoretical model in order to extrapolate up to S34(0)


OUTLINE

MOTIVATION

MEASUREMENT OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


M. Carmona-Gallardo

THANKS FOR YOUR ATTENTION

OUTLINE

MOTIVATION

MEASUREMENTS OF (E)

CMAM

SET UP


OBSERVABLES

RESULTS


mariano carmona gallardo grupo de física nuclear experimental instituto de estructura de la materia...

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