Decay ofRh98

Abstract

The decay of Rh has been studied using p and P spectroscopy techniques. The Ru(n, pn) reaction was used to produce Rh and the activities were transported to a low background counting station using a He-jet system. The P end point energy has been determined from the decay of Rht o Ru. The end-point energy determined in this study differs considerably from an earlier study using similar technique but agrees well with that of an earlier (p, n) reaction study. The present study has also resulted in a modified decay scheme (partial) for the decay of Rh. ]. The authors reported P feedings to a number of states in ssRu from the ground state of ssRh; the P transitions to the 0+) 2+) and 4+ states of the ground state band in Ru were observed with intensities of 10%, 70%, and 5%, respectively. This, in turn, did not allow an unambiguous spin-parity assignment for the ground state of Rh [1,2]. The P end-point energy was also determined in the above study, which, however, differs considerably, as much as 600 keV, from the value of 5057(10) keV obtained earlier from a 9sRu(p, n) reaction study [3]. The atomic mass table of Wapstra and Audi [4] has reported the latter value, which also agrees with the predictions of other mass tables [5].It was hoped, therefore, that a careful study of the decay of Rh~should help remove the above discrepancy in the end-point energy and may also lead to an improved decay scheme for 9 Rh decay. In this Brief Report the experimental determination of the P end-point energy using singles and coincidence P-p spectroscopy is reported. The modifications in the decay scheme that have resulted f'rom the present study are discussed.The nucleus ssRh was produced in the 9 Ru(n, pn) reaction with an a beam &om the Cyclotron at the Variable Energy Cyclotron Centre, Calcutta. The target was natural ruthenium of thickness 10 mg/cm2 deposited on a 25 pm Al foil. The incident beam energy was chosen to be 30.25 MeV, which was decided on the basis of the relative p-ray excitation function measurements of 98Rh with respect to other products, in the incident beam energy range from 25 to 42 MeV (on target). The recoil products were transported to a low background counting station, 10 m away &om the target chamber, using a Hejet recoil transport system [6] and collected on a 10 pm thick Mylar foil.The telescope for P-particle detection consisted of two NE102 plastic scintillator detectors; the AE detector (for p-rejection) was 500 pm thick and 25 mm in diameter, and the E detector was 15 cm thick and 15 cm in diameter. The AE detector was placed very close to the collection foil, and the E detector was suitably placed so that only the P particles which pass through the b, E de-6 10 5 10 4 (n 1oz: c3 10 2 10 1 10 I I I I I I 1150 1350 1550 1750 1950 CHANNEL NUMBER FIG. 1. Relevant portion of a typical singles p-ray spectrum.tector are collected in the E detector. The p-ray detector was a 10% HPGe with an energy resolution of 2.0 keV at 1332 keV. The p-ray detector was placed in a close geometry with respect to the acti...

Band structures in doubly oddRh98

“…The investigations from the β + and EC radioactive decay spectroscopy of 98 Rh [45] have led to identification of the ground state with T 1/2 = 8.7 min and an isomeric state with T 1/2 = 3.5 min. Banerjee et al [46] have assigned I π = 2 + for the ground state (T 1/2 = 8.7 min) of 98 Rh on the basis that it undergoes β decay only to the 2 + state of the even-even 98 Ru nucleus, and there is no direct β feeding to either the 4 + excited state or the 0 + ground state. The excitation energy of the isomeric state with T 1/2 = 3.5 min is not known.…”

Secure MEReq: A Tool Support to Check for Completeness of Security Requirements

“…Besides, Hardy and Lew can review the "Suggestion" and "Lexical Density by Sentence" as in Figure 3 (5). In order to allow Lew to get better understanding of the requirements structure, he then clicks the "Next" button to review the analysis of security requirements (6).…”

Nuclear structure studies close to N = Z = 50

“…The upper part of the level scheme proposed earlier has been modified. The decay of 98 Rh has been studied by Banerjee et al [38] Ru(d, xnyp) reactions. In order to decide whether the cascade is based on the I π = (2 + ) ground state with T 1/2 = 8.7 m, or on the isomer I π = (5 + ) with T 1/2 = 3.5 m, the measurements were performed by Beharet al [17] with an α-particle ON/OFF beam experiment.…”