Decay energies of the low-spin states of147Tb and148Tb

Abstract

Using 112Cd(4~ pxn) reactions and 7-ray spectroscopy, the EC//? § and EC(K)//? + probability ratios were determined for individual /?-transitions in the 147Tb(1.6 h)--,a47Gd and 148Tb(60 min)~148Gd decays. Under assumption of applicability of theoretical ratios for allowed /?-decays on the first-forbidden nonunique transitions studied here, the experimental ratios were converted into information on decay energies. Combining the results with the known masses of 147,148Gd and Q~ values of neutron-deficient holmium-to-lutetium isotopes, mass excesses could be determined for 147Tb, 148Tb, low-spin 151H0, low-spin 152H0, 155Tm, 156Tm and 159Lu.

Atomic masses of147m, 148m, 149m Tb,148Dy,150m, 152m Ho derived from decay properties

“…In the present communication we report on Q~c measurements of 147m, 148m, 149rnTb ' 148Dy and 15~ continuing our earlier work of mass 9 measurements by y-spectroscopic techniques [5][6][7].…”

Beta-delayed gammas and QEC-values in the decays of150m,152mHo and149Dy

“…both are too large by 200 keV, or that the present result and the value of [27] correspondingly are too small. Taking into account feeding would even increase the result of [3] by 40 keV, and thus enlarge the difference.…”

“…Since the e-decay energies and the isomeric energies of 148mTb and 1s2mHo are well known [4,26], the QEc-Value measurements can be related to one another. Using our Q~c-value for 152mHo, 6263 t~+89~-8oJ keV, together with the QEc-Value for 14aTb, 5295(45) keV [27], the energy sum of the circle is -30(96)keV, hence giving a perfect fit. Using the QEc-values, 6470(80)keV of ~52mHo, and 5730(30) keV of 148Tb from the same experiment [3], the corresponding circle sum is + 108 (85) keV, also being close to zero.…”

“…Table 1). from [27], c) from [4], d) from this work, e) from [3], f) from [1], g) from [28] Within another closed mass circle, 149Dy, 149Tb, 153Er, lS3Ho, the decay energy of 149Dy can be used to calculate the still unknown QEc-Value of 153Er. This calculation makes use of the e-decay of lS3Er between the two 7/2-states with Q,=4796(3)keV [19] and the e-decay of the high-spin ~S3Ho leading to the 11/2-state at 35.9keV in 149Tb with Q==4015(10)keV [29].…”

On the beta decay of148gTb

“…In connection with a determination of the decay energies of the low-spin states of t47'a4STb [1] additional gates were consequently applied on the recorded 77-coincidence data in order to verify the available decay schemes. While agreement was achieved with the published data on ~TTb [2], it emerged that the information obtained on the decay of ~4STb did not agree with the decay schemes given letter is given in parenthesis, the coincidences were too weak to be unambiguously indentified (see also Fig.…”