Accelerated Emission of Gamma Rays from the 31-yr Isomer of 178 Hf Induced by X-Ray Irradiation

  title={Accelerated Emission of Gamma Rays from the 31-yr Isomer of 178 Hf Induced by X-Ray Irradiation},
  author={Carl B. Collins and Farzin Davanloo and M. C. Iosif and R{\'e}mi Dussart and J. M. Hicks and Sarkis Karamian and Calin Alexandru Ur and Iovitzu Popescu and Vladimir Kirischuk and J. J. Carroll and H. Roberts and Patrick Mcdaniel and C. E. Crist},
  journal={Physical Review Letters},
A sample of 6.3{times}10{sup 14} nuclei of the 4-quasiparticle isomer of {sup 178}Hf having a half-life of 31thinspthinspyr and excitation energy of 2.446thinspthinspMeV was irradiated with x-ray pulses from a device typically used in dental medicine. It was operated at 15thinspthinspmA to produce bremsstrahlung radiation with an end point energy set to be 70 or 90thinspthinspkeV. Spectra of the isomeric target were taken with a high purity Ge detector. Intensities of selected transitions in… 

Search for X-ray induced decay of the 31-yr isomer of 178Hf using synchrotron radiation

Isomeric {sup 178}Hf (t{sub 1/2} = 31 yr, E{sub x} = 2.446 MeV, J{sup {pi}} = 16{sup +}) was bombarded by a white beam of x-rays from the Advanced Photon Source at Argonne National Laboratory. A

Search for X-Ray Induced Decay of the 31-yr Isomer of 178-Hf at Low X-Ray Energies

The 31-yr isomer of {sup 178}Hf at excitation energy 2.446 MeV, and with J{sup {pi}}, K= 16+, 16, has been the object of several studies for possible mechanisms that might trigger isomer decay to the

Study of the gamma emission from the 31-yr isomer of 178Hf induced by x-ray irradiation

A sample containing 6.3×1014 nuclei of the 16+ isomer of 178Hf having a half-life of 31 yr and an excitation energy of 2.446 MeV was irradiated with x-ray pulses from a device operated at 15 mA to

Gamma-Ray Transitions Induced in Nuclear Spin Isomers by X-Rays

Because of the high density of energy storage and the large cross section for its release, nuclear spin isomers have attracted considerable recent interest. The triggering of induced gamma emission

Nuclear resonance spectroscopy of the 31-yr isomer of Hf-178

Induced release of the high energy densities stored in isomeric nuclear states may be important in the development of ultrashort wavelength lasers. Such a release could compensate the spontaneous

Induced decay of 178Hfm2: Theoretical analysis of experimental results

This article reviews experimental results obtained recently on the x-ray-induced acceleration of the decay of the long-lived isomer {sup 178}Hf{sup m2}. Two basic mechanisms for the induced decay are

Preparation of the 178m2Hf isomer used in the induced gamma decay experiment by X-ray from synchrotron radiation facility

It is widely acknowledged that the 178m2Hf nuclide is the most suitable substance to study the decay characteristic of the isomer induced by low-energy X-ray. In order to conduct the experiment on

An experimental perspective on triggered gamma emission from nuclear isomers

The study of triggered depopulation of nuclear isomers, with accompanying gamma emission, is a rapidly-changing field that is only now attaining some degree of maturity. Because isomer decays via

Decay of isomers stimulated by laser radiation

A theory is presented for the induced decay of isomer levels for nuclei exposed to a laser field, which couples the initial isomer level to intermediate higher lying levels with short lifetimes. We