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Level crossing experiments with atomic beams as absorber
ABSTRACTS OF CONTRIBUTED PAPERS, SECTION B
281
G. W. Series (Ox/ord): Is there a significant correction for t h e c o u n t e r - r o t a t i n g c o m p o n e n t of t h e oscillating field ? F. D. Bedard: W e m a d e no correction, b u t we tried several R F field values and noticed no difference. B8
H. BUCKA, G. HEPPKE and J. NEY, I n s t i t u t ftir K e r n p h y s i k der Technischen U n i v e r s i t g t Berlin.
Level Crossing Experiments with Atomic Beams as Absorber. x) M e a s u r e m e n t s concerning t h e 3dx04p aPs/2 level of Cu I and 4dx05p ~Pn/z level in t h e A g - a t o m were p e r f o r m e d using a t o m i c b e a m s as absorber. T h e exciting light was p r o d u c e d b y a strong discharge light-source w i t h liquid copper (silver) as cathode. T h e a t o m i c b e a m o v e n was h e a t e d b y electron b o m b a r d m e n t . R e g a r d i n g the copper resonance line ~ ---- 3247/~ we observed besides t h e zero field level-crossing a first h y p e r f i n e structure-crossing n e a r 145 Oe, which shows a slight a s y m m e t r y caused b y t h e o v e r l a p p i n g of t h e signals of t h e two isotopes S3Cu and 65Cu. W i t h higher m a g n e t i c field s t r e n g t h f u r t h e r signals were observed. F r o m t h e w i d t h of t h e signals we deduce a m e a n life t i m e ~ = 1/~ ~ 7.7 × 10 -9 sec and f r o m a rough analysis h y p e r f i n e s t r u c t u r e values a(63Cu) m (190 + 6) M H z and a(SSCu) ~ (205 + :k 7) M H z using t~(65Cu)//~(83Cu) > 1 and t h e order of t h e q u a d r u p o l e m o m e n t s . Concerning t h e Ag resonance line g = 3280 A we observed a v e r y strong zero field effect w i t h full h a l f w i d t h of a b o u t 13 Oe, and in t h e wing of the signal a small comp o n e n t (a-excitation, observing unpolarised fight). F u r t h e r e x p e r i m e n t s u n d e r inv e s t i g a t i o n will be discussed. B9
H. BUCKA, J. EICHLER, G. y o n OPPEN, I n s t i t u t fiir K e r n p h y s i k der Technischen Universitiit Berlin.
Li#time o/ the aF4 State in the B a I Spectrum. A n a t o m i c b e a m w i t h m e t a s t a b l e n e u t r a l B a - a t o m s in t h e 3Ds-state, which was excited b y electron impact, was i l l u m i n a t e d b y a linearly polarized fight b e a m of t h e t r a n s i t i o n SF4 -- aDs g ---- 7060 A. A m a g n e t i c field p e r p e n d i c u l a r to t h e fight b e a m and to its polarization was applied. T h e depolarization of t h e resonance fight b y t h e m a g n e t i c field (Hanle-effect) was observed w i t h Z e e m a n - m o d u l a t i o n and lock-in detection. P r e l i m i n a r y m e a s u r e m e n t s yielded a lifetime o f , ~ 1,5 × 10 -s sec for t h e SF4-state. F o r t h e e v a l u a t i o n the gd-factor was calculated to be g j = 1.25. DISCUSSION
Th. G. Eck (Cleveland): Are you p l a n n i n g to use polarized light to look for t h e ]AM[ = 1 crossings? H. Bucka: W e are t r y i n g to search for A M ----- 1 crossings. G. W. Series (Ox/ord): H a v e you m a d e a n y a t t e m p t s to calculate t h e hyperfine coupling c o n s t a n t s f r o m y o u r o b s e r v a t i o n of t h e H e y d e n b u r g effect ? H. Bucka:We are t r y i n g to m a k e a n analysis corresponding to t h e calculations of H e y d e n b u r g , to get h y p e r f i n e s t r u c t u r e splittings due to the slight influence of t h e m a g n e t i c field on t h e m a t r i x elements. 1) Complete paper published, Ann. Phys. 16 (1965) 302; Z. angew. Phys. 20 (1966) 354.
281
G. W. Series (Ox/ord): Is there a significant correction for t h e c o u n t e r - r o t a t i n g c o m p o n e n t of t h e oscillating field ? F. D. Bedard: W e m a d e no correction, b u t we tried several R F field values and noticed no difference. B8
H. BUCKA, G. HEPPKE and J. NEY, I n s t i t u t ftir K e r n p h y s i k der Technischen U n i v e r s i t g t Berlin.
Level Crossing Experiments with Atomic Beams as Absorber. x) M e a s u r e m e n t s concerning t h e 3dx04p aPs/2 level of Cu I and 4dx05p ~Pn/z level in t h e A g - a t o m were p e r f o r m e d using a t o m i c b e a m s as absorber. T h e exciting light was p r o d u c e d b y a strong discharge light-source w i t h liquid copper (silver) as cathode. T h e a t o m i c b e a m o v e n was h e a t e d b y electron b o m b a r d m e n t . R e g a r d i n g the copper resonance line ~ ---- 3247/~ we observed besides t h e zero field level-crossing a first h y p e r f i n e structure-crossing n e a r 145 Oe, which shows a slight a s y m m e t r y caused b y t h e o v e r l a p p i n g of t h e signals of t h e two isotopes S3Cu and 65Cu. W i t h higher m a g n e t i c field s t r e n g t h f u r t h e r signals were observed. F r o m t h e w i d t h of t h e signals we deduce a m e a n life t i m e ~ = 1/~ ~ 7.7 × 10 -9 sec and f r o m a rough analysis h y p e r f i n e s t r u c t u r e values a(63Cu) m (190 + 6) M H z and a(SSCu) ~ (205 + :k 7) M H z using t~(65Cu)//~(83Cu) > 1 and t h e order of t h e q u a d r u p o l e m o m e n t s . Concerning t h e Ag resonance line g = 3280 A we observed a v e r y strong zero field effect w i t h full h a l f w i d t h of a b o u t 13 Oe, and in t h e wing of the signal a small comp o n e n t (a-excitation, observing unpolarised fight). F u r t h e r e x p e r i m e n t s u n d e r inv e s t i g a t i o n will be discussed. B9
H. BUCKA, J. EICHLER, G. y o n OPPEN, I n s t i t u t fiir K e r n p h y s i k der Technischen Universitiit Berlin.
Li#time o/ the aF4 State in the B a I Spectrum. A n a t o m i c b e a m w i t h m e t a s t a b l e n e u t r a l B a - a t o m s in t h e 3Ds-state, which was excited b y electron impact, was i l l u m i n a t e d b y a linearly polarized fight b e a m of t h e t r a n s i t i o n SF4 -- aDs g ---- 7060 A. A m a g n e t i c field p e r p e n d i c u l a r to t h e fight b e a m and to its polarization was applied. T h e depolarization of t h e resonance fight b y t h e m a g n e t i c field (Hanle-effect) was observed w i t h Z e e m a n - m o d u l a t i o n and lock-in detection. P r e l i m i n a r y m e a s u r e m e n t s yielded a lifetime o f , ~ 1,5 × 10 -s sec for t h e SF4-state. F o r t h e e v a l u a t i o n the gd-factor was calculated to be g j = 1.25. DISCUSSION
Th. G. Eck (Cleveland): Are you p l a n n i n g to use polarized light to look for t h e ]AM[ = 1 crossings? H. Bucka: W e are t r y i n g to search for A M ----- 1 crossings. G. W. Series (Ox/ord): H a v e you m a d e a n y a t t e m p t s to calculate t h e hyperfine coupling c o n s t a n t s f r o m y o u r o b s e r v a t i o n of t h e H e y d e n b u r g effect ? H. Bucka:We are t r y i n g to m a k e a n analysis corresponding to t h e calculations of H e y d e n b u r g , to get h y p e r f i n e s t r u c t u r e splittings due to the slight influence of t h e m a g n e t i c field on t h e m a t r i x elements. 1) Complete paper published, Ann. Phys. 16 (1965) 302; Z. angew. Phys. 20 (1966) 354.