Explain Nuclear Transmutation by Protons?

 Transmutation by Protons 

  

                The proton is a hydrogen nucleus denoted by ₁H¹ or "p" in a nuclear reaction. It was discovered by Rutherford in 1919. It was used as projectile for nuclear transmutation in 1932 by Cockcroft and Walton. 

 

               The first case of artificial nuclear disintegration with protons is carried out when protons are used as projectiles on lithium target. 

             Cockcroft and Walton bombarded lithium with protons having energies of 0.1MeV to 0.7MeV. The scintillations caused by particles ejected from the lithium were observed on a zinc sulfide screen placed a short distance away. The emitted particles are identified as alpha particles through their tracks in a cloud chamber.

            The nuclear reaction when lithium is bombarded with protons is given as 

                    ₁H¹      +    ₃Li⁷ →   [₄Be⁸]  → ₂He⁴      +    ₂He⁴

          

            ^{Some examples of nuclear transmutation by protons are as under.}

 ( P, α) Nuclear Reactions

            The general type of (P, α) nuclear reaction is 

              ₁H¹      +    _ZX^A →   [ _Z+1Cn^A+1]  → _Z+1Y^A-3      +    ₂He⁴

             ^{Where Cn stands for compound nucleus.} 

  ^Examples

       ^{The (P, α) reaction is written as when lithium is bombarded with proton}

             ₁H¹      +    ₃Li⁷    →   [₄Be⁸]    →   ₂He⁴      +    ₂He⁴

      

          ^{Where ₄Be8} is very unstable and splits into two α-particles. First alpha particle has energy of several MeV. 

         The (P, α) reaction is written as when fluorine is bombarded with proton.

            ₁H¹      +    ₉F¹⁹    →   [₁₀Ne²⁰]    →   ₈O¹⁶      +    ₂He⁴

        The (P, α) reaction is written as when boron is bombarded with proton.

       

       ₁H¹      +    ₅B¹¹    →   [₆C¹²]    →   ₄Be⁸      +    ₂He⁴

       ^{Where ₄Be8} is highly  unstable and splits into two α-particles.

       ₄Be⁸     →   ₂He⁴      +    ₂He⁴

   

       ^{The final result of the bombardment is three alpha particles.} 

     ₁H¹      +    ₅B¹¹    →   ₂He⁴      +     ₂He⁴      +     ₂He⁴      

     The reaction is called multiple particle production.

(P, n) Nuclear Reactions

Definition

          " The reaction is called (P, n) reaction when proton is bombarded on target nucleus, the result gives one of the product particles as a neutron." 

       The (p, n) reaction are endothermic because Q is usually negative. 

       The general type of (p, n) reaction is 

            ₁H¹      +    _ZX^A →   [ _Z+1Cn^A+1]  → _Z+1Y^A      +    ₀n¹

 ^Examples

         ₁H¹      +    ₅B¹¹    →   [₆C¹²]    → ₆C¹¹      +    ₀n¹ 

       

        ₁H¹      +    ₈O¹⁸  →     [₉F¹⁹]    → ₉F¹⁸      +    ₀n¹ 

(P, γ) Nuclear Reactions

Definition

      " The nuclear reaction in which bombarding proton is simply captured by a target nucleus and generated compound nucleus is unstable which becomes less unstable by emitting a γ- ray photon rather than a neutron or alpha particle is called (P, γ) nuclear reaction. "

        The gamma ray photons emitted in these reactions are highly energetic. 

       The general type of reaction is 

          ₁H¹      +    _ZX^A →   [ _Z+1Cn^A+1]  →  _Z+1Y^A+1   +    γ

 Examples 

        ₁H¹      +    ₁₃Al²⁷ →   [₁₄Si²⁸]  →  ₁₄Si²⁸   +    γ 

          ₁H¹      +    ₆C¹²   →    [₇N¹³]      →  ₇N¹³   +    γ 

(P, d) Nuclear Reactions

Definition

      " The nuclear reaction in which deuterons are produced when disintegration is caused by protons are called ( p, d) reactions." 

         

  ₁H¹      +    ₄Be⁹ →   [₅B¹⁰]  →  ₄Be⁸   +    ₁H²