63Ni-based β-electric current source

Abstract

The possibility of developing a β-electric atomic battery with microwatt power based on 63 Ni with a lifetime of at least 30 years is analyzed. A method is proposed for large-scale commercial production of 63 Ni with concentration 80-90% in the final product. A design of a β-electric transducer based on macroporous silicon with optimized configuration and macropore depth (microchannels) is presented and analyzed. 63 Ni is deposited on the inner surface of the microchannels.A laboratory model of an atomic battery based on 63 Ni has been fabricated. The working parameters and the current-voltage characteristics of a 500 µW(e) atomic battery based 63 Ni (90% concentration) are presented.The development and adoption of objects of microsystems engineering in practice raise the problem of developing a new generation of microwatt-range miniature high-capacity autonomous power sources that meet modern requirements for the specific power capacity, service life, continuous operating time, and reliability during the entire period of service in a wide temperature range. In our opinion, atomic batteries operating on the β-electric effect best meet these requirements. This effect is an analogue of the photoelectric effect, the only difference being that the electron-hole pairs in a crystal lattice of the semiconductor are formed by β particles and not light.The operation of a β-electric transducer can be compared with the operation of a photoelectric transducer under conditions of low illumination. A β-electric transducer is a semiconductor component with a p-n junction in contact with a source of β radiation. The energy required for producing electron-hole pairs arises as result of the coulomb interaction of the β particles with electrodes of the crystal lattice; the number of nonequilibrium carriers which are formed is proportional to the energy of the incident particle flux.The first works on β-electric transducers, using 90 Sr, appeared in the mid-1950s [1]. Subsequently, similar studies were performed using 147 Pm and tritium [2][3][4][5].The present article examines the use of 63 Ni in an atomic battery for the electric power range 100-500 µW. Radionuclides emitting β particles whose energy spectrum does not exceed the threshold for radiation damage in a semiconductor transducer are applicable for miniature β-electric atomic batteries (Table 1). The short half-life of 147 Pm, previously used in atomic batteries, does not give stable parameters for operating times exceeding three years. An advantage of tritium is that the commercial production of tritium in large quantities and with adequate isotopic purity has been mastered. 63 Ni competes with tritium. As a source of energy it is attractive because of, first and foremost, its long half-life T 1/2 = 100 yr.