Scattering, structure and tracking of exotic nuclei and nuclear instrumentation

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Scattering, structure and tracking of exotic
nuclei and nuclear instrumentation

• Balance of previous results.
• Research group
• Scientific objectives
• Landmarks

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Scattering, Structure and Tracking for Exotic
Nucleiand Nuclear Instrumentation
Joaquín Gómez Camacho Jose Manuel Espino
Navas Marcos Alvarez Ivan Mukha Javier
Praena Ziad Abou-Haidar Begoña Fernández Alejandro
Garzón Juan Pablo Fernández
EXPERIMENTS WITH EXOTIC BEAMS BEAM TRACKING FOR
FAIR INSTRUMENTATION AT CNA
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Previous projects
FPA2002-04181-C04-04 FPA2005-04460
FPA2006-13807-c02-01

• Theory
• Structure and Reaction Calculations of exotic
  nuclei (Effect of the Continuum).
• Experiments
• Elastic and break-up measurements in radioactive
  beam facilities. (Dynamical effects)
• Instrumentation
• Use of local facility (CNA Tandem).
• Contribution to FAIR project (Low Energy Beam
  Tracking).

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Evolution of the group
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Experimental Team at CNA (Sevilla)
Centro Nacional de Aceleradores
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MINISTERIO DE EDUCACION Y CIENCIA
Parque Tecnológico Cartuja93, Avda.Thomas Alva
Edison nº 7, E-41092 Sevilla. Spain Phone
34.95.4460553, Fax [phone] cna_at_us.es
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3MV accelerator
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Beam lines (7)
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Cyclotron 18 MeV (protons), 9 MeV (deuterons)
7 ports for production of radioisotopes PET 18F,
11C, 13N, 15O
1 external beam ionic implantation, radiation
damage
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SARA, AMS system in CNA
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Experiments with exotic beams
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NEUTRON RICH HALO NUCLEI
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We study the properties of weakly bound, neutron
rich, exotic nuclei by scattering them at low
energies in the strong coulomb field of a heavy
target, and measuring elastic and break-up cross
sections
13C 13.8 s
12B 13.8 s
11Be 13.8 s
12Be 23.6 ms
14Be 4.35 ms
13Be 806 ms
9Li 179 ms
10Li 806 ms
11Li 8.5 ms
6He 806 ms
8He 119 ms
7He 806 ms
9He 806 ms
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Why? 2p-landscape
One and Two-proton radioactivity
We study the properties of unbound, proton rich,
exotic nuclei by producing them in a collision,
letting them decay in flight and tracking the
protons and the heavy fragment
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Experiments performed
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E1104 _at_ TRIUMF HALO EFFECTS IN 11Li 208Pb
at 2.2, 2.7 MeV/u
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Preliminary interpretation of data Break up
probability vs distance of closest approach

• Break up at extremely long distances!
• The slope is proportional to the excitation
  energy of the relevant states of the system (9Li
  2n)
• Ebu m h v/ 4 p 0.6 MeV
• The value of ln (?br /?el) at a certain rmin
  is related to the B(E1) to the revelant BU states
  
• Large bu cross section ? Large B(E1) to states
  of low excitation energy

All data fall on a straight line !
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B(E1) Values
Realistic 3-body calculation of 11Li using an
effective separation energy for the 2n-9Li
system. Black line Relative energy S2n Over
estimate B(E1) The square mass
radius Redline improved 3-body model to
reproduce the density probability and square mass
radius of the ground state of 11Li. Gives a good
account of the B(E1) and of our scattering
data.
Zinser et al, NPA619(1997)151 Nakamura et al.,
PRL 96 (2006) 252502
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Experiments planned
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9Li 11Li data for the same CM energy, above
Coulomb barrier
Conditions ?Ef Eb ??? 70 keV (dynamic
choice) ? Pixels (3x3mm2)
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1.1. Scattering of halo nuclei.

• J. Gómez-Camacho, M.Alvarez, J.P.Fernández,
  Postdoc.
• Landmarks
• Analysis of 11Li experiment at TRIUMF
• Perform 11Be experiment at TRIUMF
• Perform 8He experiment at GANIL
• Resources Postdoc, Detectors, Travel

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S1202 _at_ TRIUMF EXPLORING HALO EFFECTS IN THE
SCATTERING OF 11Be ON HEAVY TARGETS
Collaboration Aarhus-Colorado-GANIL-Gothenburg
-Huelva-Louisiana-Madrid-Sevilla-St.
Mary-TRIUMF-York
503 keV
10Ben
320 keV
½-
½
11Be
B(E1) 0.116(12) e2fm2
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1.2. 2p decay and in-flight tracking.

• I. Mukha, M.Alvarez, J.M. Espino, Postdoc.
• Landmarks
• 30Ar experiment at GSI
• Tracking experiments at GSI with slowed-down
  beams.
• Resources Postdoc, Detectors, Consummables,
  Travel

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Beam tracking for FAIR
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Motivation for tracking low-energy experiments
TRACKING
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Se-D Detector
10KV
Focal plane size 10 x 40 cm2
SeD used in VAMOS - GANIL
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2.1. Complete the tracking chamber in CNA.

• Achieved
• Pressure 1-4 10-6 mbar
• Detector holder ready
• High voltage and current
• Detector connections LEMO 1 and 18 pins, BNCs
• Landmarks
• Tests with detector dummies (vacuum, gas,
  protection systems).
• Install electronics and DAQs devices.
• Test detector signals with Si detectors
• Test Tracking prototype.

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Target Holder
Detectors
Beam Line
intermediate chamber
1.0x1.0x1.5m chamber
FIRST TEST 2010!!!
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2.2. Tracking prototype for FAIR.

• Achieved
• Tracking experiments at GSI with slowed-down
  beams.
• Construction of mini-SeD
• Tests of time resolution
• Tests of space resolution
• Landmarks
• Improve fast electronics
• Tracking experiments at GANIL with SeD (2009)
• Tracking experiments at CNA with SeD (2010)
• Tracking prototype and TDR for FAIR low energy
  tracker (2011)

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MINI-SeD construction and tests. Saclay-Sevilla-GA
NIL (10x10 cm2 )
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Mini-SeD Sevilla
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Space resolution
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Position resolution (strips)
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Time resolution
Foil
Si detector
SeD
Se-
Se-
MiniSeD
SeD
Alpha source
MiniSeD
Fuente
Detector de Si
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Time signal (anod)
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Electronics

• N978 (FAST AMP)

• V792 (QDC)

• Mini-SeD2

2828 CH
2828 CH
2828 CH
CATODO lt x, y gt

• KBTD (PRE AMP)

• FILTRO

Saclay (noisy)

• MVME5500 (MIDAS)

• CRATE

• FILTRO

GANIL CATS (slow)

• N471A
• (POWER SUPPLY)

• CPLEAR (PRE AMP)

1616 CH
1616 CH
1616 CH
CATODO lt x, y gt

• Mini-SeD1

• N978 (FAST AMP)

• V792 (QDC)

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3.1. Neutron beam line at CNA

• J.Praena, J.M.Espino, J. Gomez-Camacho,
  Tecnician.
• Landmarks
• Preliminary measurements, pulsed beam.
• Internal report Scientific commitee approval
• Technical publication on neutrons at CNA
• Resources Postdoc, Detectors, Travel

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Nuclear Technology at CNA
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3.1. Neutron beam line at CNA

• Goal
• Provide neutron beams for detector tests and
  development and applications.
• Achieved
• Pulsed proton beam with Behlke switch
• Neutron dosimetry test in Tandem hall
• Landmarks
• Target design for Tandem (with CIEMAT).
• Degrader and target design for Cyclotron
• Internal report Scientific commitee approval
• Technical publication on neutrons at CNA

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Estudios de producción de 8Li y de condiciones
de ruido de fondo (1/2)

• The goal of the experiment is the measurement of
  the beta decay of Li-8 by means of the reaction
  7Li(d,p). The Li-8 beta decay and the energy
  spectrum are measured for several deuterium
  energies. This experiment is one of a set which
  has as objective the production of high energy
  monochromatic beams of electrons and positrons
  for the calibration and study of the response
  function of ?-detectors.

natLi
Tandem CW mode
Behlke Switch
Deuterium beam
?E/E
e-
High Voltage Power Supply (ORTEC)
Fast High Voltage Transistor Switch HTS 31-GSM
Power Supply, 18V, 1.2A
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Develop a neutron beam line at CNA
Two positions 66 cm, 0 cm.
TARGET, natLi 7Li(p,n) Q-1.644 MeV,
Threshold1.88 MeV
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Neutron dosimetry
Current at FC3
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Other applications of Ciclotron external line
Astrophysics
Proton Distribution
18 MeV
Lithium ? 50 ?m
Graphite ? 1.75mm
It is needed to check other materials as
shaper. Perhaps it is possible to find a shaper
with lower straggling in the proton
distribution. I think I will not find good
results but it could be done. Temperature
problems also have to be checked.
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Propuesta nTOF Física Médica - Astrofísica
Destrucción celulas tumorales

• Medir ?(n,?) y ?(n,?) de 0 1 MeV.
• ?(n,?) ? Nucleosíntesis, sobreproducción de 36S
  factor 10 ? 6.
• ?(n,?) ? Física Médica, diferencias del doble en
  ?? de la resonancia a 13.5keV.

45Sc(p,n) con Ep2.915MeV ? En13.98keV y 1.88keV
a 0º Podríamos intentar hacer una medida previa
en el CNA de (n,?)
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3.2. Particle detectors for medical usage

• Goal
• Use Si detectors to determine the dose received
  by a dummy in radiotherapy.
• Achieved
• Initial tests of SSSSD with medical accelerators
• Preliminary calibration
• Landmarks
• Test and calibration of IMRT Si strip detector
• Investigate use of DSSSD
• Report for INABENSA

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• Tests of SSSSD detector in a hospital accelerator

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• Qué hemos hecho hasta la fecha.

• Simulaciones Montecarlo (Miguel, José M. Q.,
  Maribel).

• Detector SSSSD, comprado a Micron Semiconductor.
• Electrónica construida por Alfredo Pérez et al
  (dpto. de Ingeniería Electrónica, ETSI).

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• Segunda prueba (abril 2009) para verificar la
  calibración y hacer las correcciones oportunas.

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Budget 3 years, k
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Thank you
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Physics Case Exotic Nuclei

• Exotic nuclei are unique quantum mechanical
  systems.
• Information about structure comes from reaction
  measurements.
• Interactions and reaction mechanisms are
  different from normal nuclei
• A thorough study of collisions of exotic nuclei
  is required.

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Experiments performed
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Experiments planned
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CD telescopes
Telescope 1
Telescope 2
2 telescopes front ? 4 quadrants x 40 um x 16
strips back ? 4 quadrants x 500 um
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DSSSD telescopes
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DINEX CD at CRC Louvain la Neuve (Belgium) 6He
208Pb PH189
22MeV
18 MeV
DE
DE
6He, elastic
6He, elastic
alphas
alphas
protons
protons
Et
Et
I. Martel, University of Huelva (Spain)
Valencia, 16 June 2005
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Elastic Scattering 6He208Pb
Elastic data show evidence of long range
absorption, which is partly explained by dipole
polarizability
6He ? 4.106 pps
6He ? 4.106 pps
Thesis of Ángel Sánchez Benítez (U. Huelva, 2005)
6He ? 5.106 pps
6He ? 1,5.105 pps
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Coupling to break-up channels
Coulomb and Nuclear coupling to the 3-body
continuum is essential to describe the elastic
data.
Thesis of Manuela Rodríguez, Univ. Sevilla, 2005
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Break-up data 6He 208Pb _at_ 22 MeV
Break-up cross sections and energy distribution
are consistent with neutron transfer to the low
energy continuum in the target
Thesis of Diego Escrig (U Complutense, in
preparation).
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Discovery of 19Mg and its two-proton decay
in-flight by tracking fragment trajectories with
micro-strip detectors

• The unknown isotope 19Mg is observed by using
  the novel tracking technique.
• Two-proton decay with T1/24.1(1.5) ps and
  Q2p0.75(5) MeV was detected by measuring decay
  vertices and fragment correlations from
  coincident 17Nepp events.
• Three-body decay mechanism of 2p
  radioactivity has been confirmed.

The S271 experiment at GSI, August 2006
Micro-strip detectors used for tracking
I.Mukha et al., Phys.Rev.Lett. 99,
(2007) I.Mukha et al., Phys.Rev. C77,
061303(R) (2008)
Collaboration GSI, Sevilla, Huelva,
Edinburgh, Moscow, Warsaw, Dubna, Santiago de
Compostela.
Dimensions 70x40 mm22, 100? strip pitch, 1000
channels http//dpnc.unige.ch/ams/GSItracker
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Experiments planned
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The 94Ag 2p decay
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Predicted half-lives of 30Ar, 69Br, 72Rb
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Two proton decay of 19Mg, the S271 experiment
(I. Mukha et al.) at GSI.
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ELISe e-A calculations and simulations. J.A.
Caballero HISPEC-DESPEC Theory group, HYDE,
Tracking
Low momentum resolution after the degrader Beam
tracking neccesary. Working Group GSI, Koeln,
Orsay, CEA Saclay, Huelva, Sevilla, Delhi. I.
Mukha coordinator.
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Tracking Conceptual Design
Simulations J. M. Quesada (Sevilla)
Choice of tracking detectors Diamond (GSI) SeD
(Saclay)
Design and detectors need to be tested for low
energy beams!
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Tracking chamber in CNA
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Tracking Chamber (Saclay)
SeD tracking detectors (VAMOS)
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Tracking tasks

• International Coordination Ivan Mukha
• Scientist in charge of tracking line J.
  Espino
• Contact experts (Saclay, GSI) done
• Establish collaboration (MOU) in progress
• Improve CNA performance in progress
• Design tracking chamber Jan. 2007
• Contract tech. Engineer Jan. 2007
• Installation of Tracking line October 2007
• Construction of a SeD prototype January 2008
• Tests in CNA 2008
• Tests in GSI 2009
• Landmark INTAC report for middle 2008 (Diamond
  vs. SeD).

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Beam quality at the LEB
S
Q
Very fast (ns) cooling
Estimation Dp/p10-3 at 300 MeV/u Dp/p0.35 at 6
MeV/u (CDR p.171.) Experiment
(56Ni at 360 MeV/u) degrader ?p/p4.5x10
-3 ? ?p/p8x10-4 NIMB 204(2003)119.
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Sevilla Group

• Beam tracking for HISPEC-DESPEC in FAIR (Ivan
  Mukha Coordinator of the tracking task).
• Build a dedicated line to test tracking detectors
  in CNA (Sevilla).
• Collaborate with GSI (diamond detectors) and
  Saclay (SeD detectors).

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I. Mukha et al., Nucl. Phys. A758 (2005)
Supernovae 1987A
Medium-time project. Nuclear astrophysics. The
aan radiative capture studied at TRIUMF.
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São Paulo Pelletron Laboratory
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Proton-proton correlations
Experimental setup
Data from Febr. 2005
Collaboration Sevilla, Huelva, Louvain-la-Neuve,
Leuven, Edinburg.
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Why? 2p-landscape
Two-proton radioactivity landscape
54Zn
19Mg
6Be
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On-line data, March 2006
Data (March 2006)
Experimental setup
?
Collaboration Sevilla, Huelva, Louvain-la-Neuve,
Leuven, LPC Caen.
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Physics Case Exotic Nuclei

• Unique quantum mechanical systems.
• Information about structure comes from reaction
  measurements.
• Interactions and reaction mechanisms are
  different from normal nuclei.