Nuclear Data Sheets for A = 166

Abstract

A b s t r a c t : N u c l e a r s t r u c t u r e d a t a p e r t a i n i n g t o a l l k n o w n A = 1 6 6 n u c l i d e s ( G d , T b , D y , H o , E r , T m , Y b , L u , H f , T a , W , R e , O s , I r , P t ) h a v e b e e n c o m p i l e d a n d e v a l u a t e d , a n d i n c o r p o r a t e d i n t o t h e E N S D F d a t a f i l e . T h i s e v a l u a t i o n f o r A = 1 6 6 s u p e r s e d e s t h e p r e v i o u s p u b l i c a t i o n ( E . N . S h u r s h i k o v a n d N . V . T i m o f e e v a , N u c l e a r D a t a S h e e t s 6 7 , 4 5 ( 1 9 9 2 ) ( l i t e r a t u r e c u t o f f d a t e 1 O c t o b e r 1 9 9 0 ) ) a n d t h e r e v i s i o n b y C . M . B a g l i n o f 1 6 6 W ( l i t e r a t u r e c u t o f f d a t e 1 6 A p r i l 2 0 0 0 ) . I t i n c l u d e s l i t e r a t u r e a v a i l a b l e b y 1 M a r c h 2 0 0 8 . S u b s e q u e n t t o t h e p r e v i o u s e v a l u a t i o n , 1 6 6 G d h a s b e e n o b s e r v e d f o r t h e f i r s t t i m e a n d t h e f i r s t o b s e r v a t i o n s o f e x c i t e d states in 1 6 6 Tb, 1 6 6 Re, 1 6 6 Os and 1 6 6 Ir have been reported; also, knowledge of collective structure in 1 6 6 Dy, 1 6 6 Ho, 1 6 6 E r , 1 6 6 T m , 1 6 6 Y b , 1 6 6 L u , 1 6 6 H f , a n d 1 6 6 T a h a s b e e n c o n s i d e r a b l y e x p a n d e d . H o w e v e r , t h e s t r u c t u r e s u g g e s t e d h e r e f o r 1 6 6 R e i s h i g h l y t e n t a t i v e a n d a f u r t h e r , m o r e d e t a i l e d s t u d y o f α d e c a y i n t o ( a n d o u t o f ) A c k n o w l e d g m e n t s : T h e e v a l u a t o r i s g r a t e f u l t o t h e r e v i e w e r o f t h i s m a s s c h a i n f o r a t h o r o u g h r e a d i n g o f t h e manuscript and for constructive comments; the evaluator also thanks the XUNDL database compilers (D. Reed, M.Lee, B. Singh) for initial data entry for 10 publications. * T h i s w o r k w a s s u p p o r t e d b y t h e D i r e c t o r , O f f i c e o f S c i e n c e , O f f i c e o f N u c l e a r P h y s i c s o f t h e U . S . D e p a r t m e n t of Energy under contracts DE-AC03-76SF00098 and DE-AC02-05CH11231.G e n e r a l C o m m e n t s : U n c e r t a i n t i e s o f a b s o l u t e γ -r a y i n t e n s i t i e s a r e c a l c u l a t e d u s i n g t h e m e t h o d o f B r o w n e (1986Br21).Throughout this evaluation, rotational band parameters are calculated from the standard energy equation:w h e r e A i s g i v e n i n k e V , B i s g i v e n i n e V , a n d t h e d e c o u p l i n g c o n s t a n t a i s d i m e n s i o n l e s s . W h e n n o t e x p l i c i t l y s t a t e d , B i s a s s u m e d t o b e 0 . T h e m i n i m u m n u m b e r p o s s i b l e o f t h e l o w e s t e n e r g y l e v e l s w a s u s e d t o calculate each set of parameters, unless noted otherwise.T h e o r e t i c a l c o n v e r s i o n c o e f f i c i e n t d a t a a r e f r o m r e l a t i v i s t i c D i r a c -F o c k c a l c u l a t i o n s u s i n g t h e f r o z e n -o r b i t a l approximation (2005KiZT).

Detailed spectroscopy of quadrupole and octupole states inYb168

“…The experimental results have been taken from Refs. [19,[30][31][32][33][34][35][36][37][38][44][45][46][47][48][49][50]. Because of the fact that the band head of the Kn = 2" band in l68Yb was not populated in the present experiment and its decay is not known, we present in Fig.…”

First observation of excited states inHg172

“…The DSSDs were calibrated using α lines at 5407, 6038 and 6315 keV corresponding to the known activities of 170 Os [22] (not visible in Figure 1), 174 Pt [23] and 172 Pt [24], respectively. The α particles associated with the decay of 173 Hg were measured to have an energy of 7208(5) keV which is in agreement with the previously reported values [14,15] but represents a more precise measurement.…”

Fast Timing Measurement Using an LaBr$_3$(Ce) Scintillator Detector Array Coupled with Gammasphere

“…A test with a 166 Ho source, decaying to 166 Er, showed the capabilities of the fast timing set-up. In the ground state band of 166 Er, according to the NNDC data base [11], the half lives of the first 2 + , 4 + and 6 + are 1815(23) ps, 118(4) ps, and 15.0(8) ps. We measured the 2 + half life with a slope fit, obtaining 1851(30) ps, which agrees well with the adopted NNDC value.…”