The use of Cf-252 Neutron source jordan by PItEY5iY

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									  The use of Cf-252
Neutron source Jordan
              Shafiq Y.Hourani
             Technical manager
City Corporation For Medical And Lab Supply
During the past two days you heard many details about two issues. First the
aspects of the Peaceful Nuclear program of Jordan. Second the various aspects of
nuclear technology namely the nuclear reactor Fuel cycle and radiation Safety .



 Thisis the out side picture of the nuclear technology. Which every body
 knows namely a reactor loaded with nuclear fuel which burns (fission ),
 producing energy, radioisotopes and neutrons.
                     Introduction
We are establishing a laboratory for neutron physics as part of
   postgraduate program in nuclear physics at the Jordan
   University. It comprises two units:
1- A 107 n\c Cf-252 neutron source, a He-3 neutron detector ,
   irradiation facility and ten types of thin metal foils to be
   used a threshold detectors for thermal and fast flux
   determination.
   2- A gamma spectrometer, based on NaI (TI)
    scintillation detector, PCI MCA board with built in
    signal processing electronics and acquisition
    software type Genie 2000. this unit is intended for
    quantitative and analysis of both prompt and
    delayed gamma spectra produced during and after
    activation of different samples. The reason of the
    choice of this particular neutron source, because it
    produces fission neutrons similar to those of
    nuclear reactor. So this will provide trained man
    power, capable of handling various jobs related to
    nuclear reactor. It is worthy to mention here that
    this is the first neutron lab in Jordan.
                    Objectives of the lab.

   The objective of of this laboratory is to qualify graduates
    and post graduates to carry on the jobs associated with
    execution of the nuclear program through under standing
    the processes taking place inside the reactor components
    during operation .
    During the past two days You heard many details about
    two issues, first the aspects of the Peaceful Nuclear
    program of Jordan Second the various of nuclear
    technology Namely the nuclear reactor Fuel cycle and
    radiation Safety . This is the out side picture of the nuclear
    technology. Which every body knows namely A reactor
    loaded with nuclear fuel which burns (fission ), producing
    energy, Radioisotopes and Neutrons. My talk will
    concentrate on the processes and events taking place inside
    the reactor and fuel.
        Main parameters of neutron source

1) Neutron energy spectrum (E)

2) Neutron yield N n/sec source strength.

3) Neutron flux n/sec.cm2 neutron field.
Fission Neutron Energy Spectrom
    Neutron parameters from interaction point of view

   Neutron energy En MeV→ fast or thermal

   Cross section σ (En) cm2 strong energy dependent

   Elastic, inelastic and reaction modes.
           Specification of the Cf-252 source

   It is one of the isotopic neutron sources
   It produces via spontaneous fission (SF) fast
    neutrons:
   *spontanous fission constitute about 3% of the total
    decay of Cf-252
   Heavy fission products
   Promot fission γ activity of the fission products
   β and γ activity of the fission products.
      Cf-252 Neutron Source Parameters
Neutron Emission Rate    2.34x10 12 n/sec gm
                          4.4 x109 n/sec Ci
                          2.2 x x106 n/sec Ci for Am-Be
Neutron per fission      3.76
                         2.5 for induced fission in the
                         reactor
Average neutron energy   2.35 MeV
Capsule size             < 1cc
Effective half life      2.68 years
Total heating            38.5 w/gr
γ Dose at 1 meter        160 RAD / h-gm
N Dose at 1 meter        2200 rem / h- gm
Nuclear fission of Cf-252 & U-235
          The Behavior of neutrons in matter

    Neutrons interact only with atomic Nuclei
    The behavior depends on En
    We will discuss three modes of interaction and
     their application in actual cases:
1)   Elastic scattering.
2)   Neutron capture.
3)   Inelastic scattering and reaction.
                  The Elastic Scattering

It is used in:
 Neutron Moderation
 Neutron Protection and Safety
 The fission of the nuclear fuel take place by thermal
    neutrons En = 0.025 eV. So we have to reduce En from 2
    MeV to 0.025 in order to ensure Sustain chain Reaction
 Neutron thermalization ( moderation ) is performed via
    neutron elastic scattering from nuclei. this is efficient in
    case of light elements such as H, D, C in the form of light
    ,heavy water and graphite respecttivly. The main
    Parameter in this process is the LETHARGY
                     ξ = Ln ( E0 / E)
              Neutron Moderators

 Nucleus               ξ           N Average No of
                                      events from
                                   2 MeV - 0.025 eV
    H                  1                  18

    D                0.728               25

    Be               0.208               85

    C                0.159               115

Absorption cross section is 330,0.46 & 3.3 mb for
              H,D,C respictively.
                 The neutron Capture

   Prompt gamma
   The nucleus capture slow neutron and is put in an
    excited state which decays in a very short
    time (<pico second) to its ground state
    emitting gamma rays of characteristic
    energy.
        Inelastic scattering

   Dominates for fast neutrons

           X (n ,ńγ) X
                 Nuclear Reactions

   It needs a threshold energy for the incident
    neutron.
   Charged particles and neutrons can be
    produced.

								
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