Zinaida Ershova

Zinaida Vasilyevna Yershova (; 23 October 1904 — 25 April 1995), , was a Russian chemist who spent her entire career in radioactive applications in the former Soviet program of nuclear weapons, later in the space program.

Biography Zinaida Yershova was born in Moscow, Russia, on October 23, 1904. In 1925, she found an employment opportunity at the Radium Institute in Petrograd where she worked under Vitaly Khlopin who later helped her securing a full-time employment at the Moscow Plant of Rare Elements, where radium was first produced in the Soviet Union industrially. In 1929, she graduated with a diploma in chemistry from the Moscow State University and moved to Kirghizstan to work in Tyuya-Muyun deposits in 1931.

In 1948, Yershova switched to polonium research when the technique was developed by Yershova and D.M. Ziva (dissolving irradiated bismuth ingots in nitric acid followed by deposition on copper or bismuth powder followed by sublimation in a vacuum) to produce large quantities of polonium-beryllium neutron sources in another new factory. The first Soviet nuclear discharge, the RDS-1, was tested in August 1949, using these products. For her contribution, she was awarded the first of her national prizes, the Stalin Prize, the same year. After 1949, she was instructed to produce tritium from the irradiation of lithium to use in the development of the Soviet hydrogen bomb. In 1952, Yershova gained her Ph.D. from the institute.

In the 1960s, the main area of work for Yershova was tritium production for research on the tritium fuel cycle for reactors and "installations" (the latter such as KB-11 in the closed city of Sarov). Polonium was used less by nuclear weapons designers but continued to be used for small-scale atomic energy sources. With B.V. Petrov she developed a 'dry' process, vacuum distillation of polonium from irradiated melted bismuth, which was safer and more efficient. Yershova studied the reactions of polonium with many different elements. Her laboratories produced polonium products for electric current generators in communications satellites (Kosmos-84 and Kosmos-90 in 1965) and three thermal blocks (in 1968, 1970 and 1972) for the moon rovers Lunokhod-1 and Lunokhod-2. She was awarded the V.G. Khlopin USSR Academy of Sciences Prize in 1968 for her work on the chemistry of polonium.

She retired from NII-9 after a 40-year career. She died in 1995 and is buried at the Vagankovo Cemetery in Moscow.

Awards 1949, 1951, 1954: Stalin Prize 1968: V.G. Khlopin USSR Academy of Sciences Prize