Barcelona, 21 de maig de 2010

Introduction: Research objectives

Detector

IGISOL system (Ion Guide Isotope Separator On-Line)

Efficiency calculation Cf-252 calibration

Data analysis

Detector IGISOL system Efficiency252Cf AnalysisIntroduction

Contents

2/20

Research objectives: “Nuclear data for physics and nuclear engineering”

Detector IGISOL system Efficiency252Cf AnalysisIntroductionIntroduction

3/20

Neutron emission after beta decay

Exotic nuclei?

BETA

Research objectives

Detector IGISOL system Efficiency252Cf AnalysisIntroductionIntroduction

4/20

Neutron emission from beta decay

Research objectives

Detector IGISOL system Efficiency252Cf AnalysisIntroductionIntroduction

5/20

Example of exotic nuclei to study

neutron BETA

Research objectives

Detector IGISOL system Efficiency252Cf AnalysisIntroductionIntroduction

6/20

Example of exotic nuclei to study

neutron BETA

Research objectives

Detector IGISOL system Efficiency252Cf AnalysisIntroductionIntroduction

7/20

Applications: Some of them are close to the path of the astrophysical r process, the determination of the full beta strength could help to improve theoretical models used for the calculation of beta decay properties (region A~90)Nuclear reactor safety. (Decay heat, fission reaction control)

International projects collaboration: Development and testing instrumentation for the FAIR facility (DESPEC collaboration)

Physics knowledge: Study different aspects of the decay of these nuclei and hence provide very complete information about their decay mechanism and structure.

Detector structure

Detector IGISOL system Efficiency252Cf AnalysisIntroduction Detector

8/20

Introduction

Reaction

Detector IGISOL system Efficiency252Cf AnalysisIntroduction Detector

9/20

Mechanisms of detecting neutrons are based on indirect methods

3He + n → 3H + 1H + 765 keV

ions

n

n

n

Polyethylenemoderator

Proportional counter

Electronic chain for data acquisition and signal processing

Detector IGISOL system Efficiency252Cf AnalysisIntroduction Detector

10/20

Software implementat: GASIFIC Fitxers binaris

Detector IGISOL system Efficiency252Cf AnalysisIntroduction IGISOL system

Ion Guide Isotope Separator On-Line:

Detector

Nuclei production

11/20

ISOLTRAP at CERN, Geneva, Switzerland SHIPTRAP at GSI, Darmstadt, Germany LEBIT at MSU, East Lansing, Michigan, USATITAN at TRIUMF, Vancouver, CanadaCPT at ANL, Argonne, Illinois, USATRIGA-TRAP at Univ. of Mainz, Germany

Study of short-lived (T1/2>1us): The nuclei of interest have to be produced and immediately

used for the experiments

Separation of the nuclei of interest from other contaminants

Very pure ion beam is achieved

Other Traps for radioactive ions:

Detector IGISOL system Efficiency252Cf AnalysisIntroduction IGISOL system

IGISOL layout

12/20

1- Ion guide

2- k130 cyclotron beamline

3- beam dump

4- acceleration chamber

5- dipole magnet (mass separation “A”)

6- switchyard

7- RFQ cooler

8- tandem penning trap

9- miniquadrupole deflector

10- electrostatic deflector and beamline to upper floor

11- experimental setups

Detector Sistema Efficiency252Cf AnalysisIntroduction IGISOL system

Ion guide

Ions are transported by a gas flow out of the gas cell and injected to the high vacuum section for further acceleration and mass separation.

Basic idea: To slow down and thermalize initially energetic recoil ions from nuclear reactions in gas. Tipically Helium.

13/20

Detector Sistema Efficiency252Cf AnalysisIntroduction IGISOL system

JYFL trap

14/20

Applying successive dipole and quadripole rf fields which lead to mass-selective cooling and centering according to:

Possibility of producing isobarically purified ion beams

B/wc=m(A)/q

JYFLTRAP is an ion trap system for cooling, bunching and isobaric purification of radioactive ion beams produced at IGISOL

Main applications are mass and Q-value measurements of exotic nuclei and preparation isobarically or even isomerically pure beams for decay spectroscopy experiments

Detector Sistema Efficiency252Cf AnalysisIntroduction IGISOL system

Photos &Pictures

15/20

Detector IGISOL system Efficiency252Cf AnalysisIntroduction Efficiency252CfIGISOL system

Detector experimental efficiency

16/20

-Spontaneous fission source Cf-252

Uncertainty 15% aprox!

- Fission products to analyze gamma peaks:

136I (1313keV)138Cs (1435keV) 140La (1596keV)

Detector IGISOL system Efficiency252Cf AnalysisIntroduction Efficiency252Cf

Gamma detector calibration

17/20

•59,5keV

•661,5keV

•1173 y 1332,5keV

•1460keV (K-40)

Energy calibration : Am-241, Cs-137 & Co-60 mixt source

• 122keV, 344,3keV, 411keV, 778,9keV,

867,4keV, 964keV, 1112keV,1408keV

Efficiency calibration: Eu-152 source

Uncertainty obtained: 7,5%

Detector IGISOL system Experiment AnalysisIntroduction Efficiency252Cf

Cf-252 Activity

18/20

Cf-252 spectrum

Spectrum area with interesting peaks:

1313keV, 1435keV & 1506keV

Zoom

Detector IGISOL system Efficiency252Cf AnalysisIntroduction Analysis

Single measures

19/20

GENIE (MCA/PC data transfer + peak analysis)

[@dest + @source + lengt + aa aa 03 + ctrl + data +

+ nºpack + ctrl + lengt + ctrl 0 +lengt + real data]

(See excel file)

Wireshark as data package capture LLC Protocol

Efficiency252Cf

PalmTop

Cheaper system according uses

ATOMKI group (Hungary)

Free licence software

Detector IGISOL system Efficiency252Cf AnalysisIntroduction Analysis

Data analysis

19/20

ROOT:

OTHER: Go4 (GSI)

GASIFIC implemented and developed by IFIC (UV) in C++ using ROOT libraries:

Cern development, multifunctional software, programable

- Binary file adquisition

- Generate user root files to analyze

- Modify correlation time between beta & neutron emittion

Links of interest

http://www.baeturia.com/neutronassos/

https://www.jyu.fi/fysiikka/en/research/accelerator/

S’ha acabat!... ???