Prompt and delayed spectroscopy of At-199

• The neutron-deficient nucleus At-199 has been studied through gamma-ray and electron spectroscopy, using the recoil-decay tagging technique. Two experiments were conducted, using a gas-filled recoil separator with a focal-plane spectrometer alone and together with a germanium-detector array at the target position. The resulting level scheme for 199At includes a new isomer with a half-life of 0.80(5) mu s and a spin and parity of (29/2(+)). The 13/2(+) isomer, which de-excites via an M2 transition to the 9/2 ground state, was measured to have a half-life of 70(20) ns. Our earlier version of the level scheme for At-197 has been updated as well.

Subject headings

NATURVETENSKAP  -- Fysik -- Subatomär fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Subatomic Physics (hsv//eng)

Keyword

HIGH-SPIN STATES

GAMMA-RAY SPECTROSCOPY

RECOIL FILTER DETECTOR

COINCIDENCE DATA SETS

NUCLEAR-DATA SHEETS

IN-BEAM

EXCITED-STATES

SYSTEMATIC BEHAVIOR

1ST OBSERVATION

MASS NUCLEI

Nuclear physics

Kärnfysik

Publication and Content Type

ref (subject category)

art (subject category)