Nuclearbattery

Idea was introduced in 1950 and patented to Tracer Lab.

Radioisotope electric power system developed by Paul Brown.

He organized an approach to harness energy from the magnetic field of alpha and beta particles using Radium-226.

Low efficiency due to loss of electrons.

Need for compact reliable light weight and self-contained power supplies.

Chemical batteries require frequent replacements and are bulky.

Nuclear reactors offer economical and technical problems.

Fuel and Solar cells are expensive and requires sunlight respectively.

Nuclear batteries have lifespan up to decades and nearly 200 times more efficient.

Do not rely on nuclear reaction , so no radioactive wastes.

Uses emissions from radioactive isotope to generate electricity.

Can be used in inaccessible and extreme conditions.

Radiations•Alpha - These are fast moving helium atoms.  They have high energy, typically in the MeV range. They also are magnetic in nature •Beta - These are fast moving electrons.  They typically have energies in the range of a few hundred keV to several MeV.•Gamma - These are photons, just like light, except of much higher energy.

RadioisotopesRadioisotopes are artificially produced, unstable atoms of a chemical element, which have a different number of neutrons in the nucleus, but the same number of protons and the same chemical properties.

CLASSIFICATION NUCLEAR BATTERY

Alternative energy technology. Provides extended battery life and power

density. Uses energy from beta particles. Beta particles from radioactive gas captured

in Si wafer coated with diode material. Absorbed radiation creates electron-hole pair. Results in the generation of electric current.

Before the radioactive source is introduced , no current flows as the electrical forces are in equilibrium.

As a beta emitter is introduced , electrons are knocked out by its energy.

Generates electron-hole pairs in the junction. When beta particle imparts more than

ionization potential the electron rises to a higher level.

Representation of basic beta voltaic conversion

Fermi voltage established between the electrodes.

Potential difference drives electrons from electrode A through the load where they give up the energy.

Electron is then driven into electrode B to recombine with a junction ion.

Betavoltaics does not have solar-cell efficiency. Electrons shoot out in all directions; hence lost. Porous Si diodes with pits provide a 3-D surface

thereby increasing the efficiency.

Energy from radioactive decay products.

Circuit impedance has coil wound on a core composed of radioactive elements.

Decay by alpha emission; hence greater flux of radioactive decay.

Schematic Diagram of an LC resonant circuit

3 – capacitor 5 – inductor9 – transformer T primary winding11 – resistance7 – core with radioactive elements

Here energy is imparted to the alpha particles during the decay of elements in the core.

This energy is introduced to circuit when alpha particles are absorbed by the inductor.

Some of energy dissipated in ohmic resistance.

This excess energy is delivered to the load connected across transformer T secondary winding.

1 – Capacitor 2 – Inductor 3 – Core with radioactive elements 4 – Transformer T primary

winding 6 _ Secondary winding 7 _ Load Load

EXTERIOR STRUCTURES In the center of cylinder have

radioisotope source. The outside is a thermionic converter Reflectors Metal tube casing

The major criterions considered in the selection of fuels are:Avoidance of gamma in the decay chain Half life( Should be more)Cost should be less.

Any radioisotope in the form of a solid that gives off alpha or beta particles can be utilized in the nuclear battery. The most powerful source of energy known is radium-226. However Strontium-90 may also be used in this Battery.

Space applications: Unaffected by long period of

darkness and radiation belts like Van-Allen belt.

Compact and lighter in weight. Can avoid heating equipments

required for storage batteries.

•High power for long time independent of atmospheric conditions..NASA is trying to harness this technology in space applications.

Medical applications:

.In Cardiac pacemakers

Batteries should have reliability and longevity to avoid frequent replacements.

•Nuclear powered laptop battery Xcell-N has 7000-8000 times more life. No need for charging, battery replacing.

Mobile devices:

Automobiles: In initial stages. No running short of fuel. Possibility of replacing ionic fuels with

its advantages.

• Under-water sea probes and sea sensors:

In sensors working for long time. At inaccessible and extreme

conditions. Use in coal mines and polar sensor

applications too.

• For powering MEMS devices : in optical switches and smart dust sensors.

Life span- minimum of 10 years. Reliable electricity. Amount of energy highest. Lighter with high energy density. Efficient, less waste generation. Reduces green house and associated

effects. Fuel used is the nuclear waste from

nuclear fission.

High initial cost of production as its in the experimental stage.

Energy conversion methodologies are not much advanced.

Regional and country-specific laws regarding use and disposal of radioactive fuels.

To gain social acceptance.

Nuclear batteries will replace most of all the chemical batteries.

Long life span make it suitable space applications.

Need for compact, reliable, light weight and long life power supplies.

Can be used in easily inaccessible and extreme conditions and reduce the rate of replacements.

Small compact devices of future require small batteries.

Nuclear batteries increase functionality, reliability and longevity.

Until final disposal all Radiation Protection Standards must be met.

Batteries of the near future.