Device and method for even-odd separation and ionization of palladium isotopes

Patent metadata

Field	Value
Publication number	US-11266952-B2
Application number	US-201816008843-A
Country	US
Kind code	B2
Filing date	Jun 14, 2018
Priority date	Dec 17, 2015
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

First and second laser beams having respective first and second wavelengths respectively excite palladium isotopes at a ground level to a first excited level then to a second excited level. At first and second excitation steps, palladium isotopes having an odd mass number are selectively excited to the second excited level, with the identity of the ion core state of each of the palladium isotopes retained between the first excited level and the second excited level. The first wavelength and the second wavelength are selected to allow the second excited level to be an autoionization level or, in a case where the second excited level is not the autoionization level, the first wavelength, the second wavelength, and a third wavelength are selected to excite the palladium isotopes at the second excited level to the autoionization level with a third laser beam having the third wavelength at a third excitation step.

First claim

The invention claimed is:

1. A method for even-odd separation and ionization of palladium isotopes including: irradiating a palladium-containing substance including a plurality of types of palladium isotopes with laser beams having a plurality of wavelengths, to selectively ionize the palladium isotope having an odd mass number, a plurality of electrons, and a nucleus from the palladium-containing substance, the method comprising:
a first excitation step of exciting the palladium isotope at a ground level to a first excited level with a first laser beam having a first wavelength; and
a second excitation step of exciting the palladium isotope at the first excited level to a second excited level with a second laser beam having a second wavelength,
wherein the first and second wavelengths are selected such that the first excitation step and the second excitation step selectively excite the palladium isotope having the odd mass number to the second excited level, and the second excited level becomes an autoionization level, the palladium isotope excited to the second excited level and having the odd mass number has an ion core state of 2 D 3/2 and the ion core state remains 2 D 3/2 between the first excited level and the second excited level, where an electron of the plurality of electrons is excited by light absorption, and
the ion core of the palladium isotope means a combination of the nucleus and the plurality of electrons excluding the electron excited by the light absorption, and the ion core state means an arrangement state of the plurality of electrons in the ion core.

2. The method for even-odd separation and ionization of palladium isotopes according to claim 1 , wherein a dichroic mirror transmits the first laser beam from a first laser emitting unit, and reflects the second laser beam from a second laser emitting unit such that the first and second laser beams overlap each other to propagate through a same path,
a polarizing element is provided at the same path, and light that has passed through the polarizing element is linearly polarized in one direction, and
the first and the second laser beams pass through the polarizing element to be incident on the palladium-containing substance in a state where the first and second laser beams are linearly polarized in directions parallel to each other.

3. The method for even-odd separation and ionization of palladium isotopes according to claim 1 , wherein the palladium-containing substance is spent nuclear fuel including radioactive palladium isotopes 107 Pd.

4. The method for even-odd separation and ionization of palladium isotopes according to claim 1 , wherein the first wavelength λ 1 is 244.9 nm and the second wavelength λ 2 is a specific value satisfying 334.0 nm<λ 2 <378.8 nm, the specific value allowing the second excited level to be the autoionization level, or
the first wavelength λ 1 is 247.7 nm and the second wavelength λ 2 is a specific value satisfying 328.8 nm<λ 2 <372.1 nm, the specific value allowing the second excited level to be the autoionization level.

5. The method for even-odd separation and ionization of palladium isotopes according to claim 4 , wherein an identical position of the palladium-containing substance is irradiated with the first laser beam and the second laser beam linearly polarized, polarized directions of the first laser beam and the second laser beam being parallel to each other, or
an identical position of the palladium-containing substance is irradiated with the first laser beam and the second laser beam linearly polarized, the polarized directions of the first laser beam and the second laser beam being orthogonal to each other, or with the first laser beam and the second laser beam circularly polarized or elliptically polarized.

6. An even-odd separation and ionization device of palladium isotopes configured to irradiate a palladium-containing substance including a plurality of types of palladium isotopes with laser beams having a plurality of wavelengths, to selectively ionize palladium isotope having an odd mass number, a plurality of electrons, and a nucleus from the palladium-containing substance, the even-odd separation and ionization device comprising:
a first laser irradiating device configured to irradiate the palladium-containing substance with a first laser beam having a first wavelength, to excite the palladium isotope at a ground level to a first excited level; and
a second laser irradiating device configured to irradiate the palladium-containing substance with a second laser beam having a second wavelength, to excite the palladium isotope at the first excited level to a second excited level,
wherein the first and second wavelengths are set such that the first and second laser beams selectively excite the palladium isotope having the odd mass number to the second excited level, and the second excited level becomes an autoionization level, the palladium isotope excited to the second excited level and having the odd mass number has an ion core state of 2 D 3/2 and the ion core state remains 2 D 3/2 between the first excited level and the second excited level, where an electron of the plurality of electrons is excited by light absorption, and
the ion core of the palladium isotope means a combination of the nucleus and the plurality of electrons excluding the electron excited by the light absorption, and the ion core state means an arrangement state of the plurality of electrons in the ion core.

7. The even-odd separation and ionization device of palladium isotopes according to claim 6 , wherein the palladium-containing substance is spent nuclear fuel including radioactive palladium isotopes 107 Pd.

8. The even-odd separation and ionization device of palladium isotopes according to claim 6 , wherein the first wavelength λ 1 is 244.9 nm and the second wavelength λ 2 is a specific value satisfying 334.0 nm<λ 2 <378.8 nm, the specific value allowing the second excited level to be the autoionization level, or
the first wavelength λ 1 is 247.7 nm and the second wavelength λ 2 is a specific value satisfying 328.8 nm<λ 2 <372.1 nm, the specific value allowing the second excited level to be the autoionization level.

9. The even-odd separation and ionization device of palladium isotopes according to claim 8 , wherein the first and second laser irradiating devices irradiate an identical position of the palladium-containing substance with the first laser beam and the second laser beam linearly polarized, polarized directions of the first laser beam and the second laser beam being parallel to each other, or
the first and second laser irradiating devices irradiate an identical position of the palladium-containing substance with the first laser beam and the second laser beam linearly polarized, the polarized directions of the first laser beam and the second laser beam being orthogonal to each other, or with the first laser beam and the second laser beam circularly polarized or elliptically polarized.

10. The even-odd separation and ionization device of palladium isotopes according to claim 6 , wherein the first laser irradiating device comprises a first laser emitting unit that emits the first laser, and a polarizing element wherein light that has passed through the polarizing element is linearly polarized in one direction,
the second laser irradiating device comprises a second laser emitting unit that emits the second laser, and a dichroic mirror that transmits the first laser beam from the first laser emitting unit, and reflects the second laser beam from the second laser emitting unit such that the first and the second laser beams overlap each other to propagate through a same path, and
the polarizing eleme

Assignees

• Riken

Inventors

• Kobayashi Tohru
• Midorikawa Katsumi

Classifications

• H01S3/0007

  Applications not otherwise provided for (working metals or other materials by laser beam B23K26/00; using photons to produce a reactive propulsive thrust F03H3/00; optical recording of measured values in general G01D15/14; optics in general G02B; holographic processes or apparatus G03H; optical marking or sensing of data record carriers G06K7/10 - G06K7/14, G06K15/12; injection heating of plasma by laser H05H1/22; acceleration of neutral particles by electromagnetic wave pressure H05H3/04) · CPC title

• B01J19/121

  Coherent waves, e.g. laser beams (lasers per se H01S3/00) · CPC title

• B01D59/34 Primary

  Separation by photochemical methods · CPC title

• Y10S423/07

  Isotope separation · CPC title