Incoherent Scattering of Gamma Rays by<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>K</mml:mi></mml:math>-Shell Electrons

Shimizu, Sakae; Nakayama, Yasunori; Mukoyama, Takeshi

doi:10.1103/physrev.140.a806

Cited by 45 publications

(5 citation statements)

References 12 publications

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“…where N T is the number of target atoms (either Na or I atoms in NaI(Tl) detectors) and the sum runs over all the electrons and over the nuclei (if they have unpaired nucleon, as it is the case for 23 Na and 127 I nuclei). F f is the incoherent scattering function [36] of the transferred momentum, q ≃ m a . As far as regards electrons, the incoherent scattering function takes into account their binding in the atoms.…”

Section: The Compton-like Effectmentioning

confidence: 99%

Investigating Pseudoscalar and Scalar Dark Matter

Bernabei

Belli

Montecchia

et al. 2006

Int. J. Mod. Phys. A

140

231

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In this paper another class of Dark Matter candidate particles: the pseudoscalar and scalar light bosonic candidates, is discussed. Particular care is devoted to the study of the processes for their detection (which only involves electrons and photons/X-rays) in a suitable underground experimental set-up. For this purpose the needed calculations are developed and various related aspects and phenomenologies are discussed. In particular, it is shown that -in addition to the WIMP cases already discussed elsewhere -there is also possibility for a bosonic candidate to account for the 6.3 σ C.L. model independent evidence for the presence of a particle DM component in the galactic halo observed by DAMA/NaI. Allowed regions in these scenarios are presented also paying particular care on the cosmological interest of the bosonic candidate.

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Section: The Compton-like Effectmentioning

confidence: 99%

Investigating Pseudoscalar and Scalar Dark Matter

Bernabei

Belli

Montecchia

et al. 2006

Int. J. Mod. Phys. A

140

231

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“…The probability of (1) is negligible because the ratio of double scattering to single scattering in the present case is estimated to be about the order of 1%; that of (2) is small enough practically because the distinct highenergy tail of the normal Compton spectrum, which is evidence for the contribution from the outershell electrons, can hardly be found in spectra 2(a) and 2(b). On the contrary, the peak C is attributed to the false coincidences due to sequential Compton scattering: first at the sample and then at the x-ray detector, 7 where the x-ray detector measured the energy of the recoil electron remaining in the detector and the y-ray detector measured the photon energy after two scatterings. The low-energy region of the spectra in Fig.…”

mentioning

confidence: 98%

X-Ray Compton-Raman Scattering from Atomic Inner-Shell Electrons

Namikawa

1984

Phys. Rev. Lett.

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Inelastic scattering of 241 Am 59.57-keVy rays from Cu and Fe was measured in coincidence with the ^-fluorescence x rays. The spectrum due to the scattering by the #-shell electrons shows the coexistence of a Compton-type and a Raman-type scattering. Doublephoton Thomson-type scattering is also identified, which is weaker than the usual Compton scattering by a factor of about 4 x 10~3.PACS numbers: 78.70.Ck X-ray inelastic scattering by a free electron is completely characterized by the energy and the momentum conservation laws. This phenomenon is the well-known Compton scattering. In contrast to Compton scattering, the feature of x-ray inelastic scattering by a bound electron varies with the value of ka even when Ho) X » E b , 1,2 where Hk is the momentum transfer and a is the radius of the binding orbital, while #a>i and E b are the energies of the incident photon and the binding orbital, respectively.When ka » 1, the peak position of the spectrum is determined only by the primary energy and by the scattering angle, but it is independent of the type of scattering atom. This is a distinct feature of Compton scattering, although Doppler broadening of the normal Compton line takes place: The spectrum includes information on the momentum distribution of the electrons in the initial state. This phenomenon is Compton scattering by a bound electron. On the contrary, when ka < 1, the peak position of the spectrum corresponds to the absorption edge of the relevant atomic orbital, but it depends neither on the scattering angle nor on the primary photon energy. The spectrum, in this case, is related to the dipole moment strength per energy. This phenomenon is x-ray Raman scattering. When ka > 1, so-called Compton-Raman scattering takes place. In this case, transition phenomena between the above two typical cases, Compton and Raman type, are expected to appear. The nature of the phenomena is not yet well understood, partly because there has been no reliable low-energy experiment so far which investigated separately the spectrum due to electrons in a single shell.In the present experiment, inelastic scattering spectra from AT-shell electrons have been measured on Cu {ka =1.02) and Fe {ka =1.16) by means of coincidence counting between the low-energy y rays scattered and the AT-fluorescence x rays subsequently emitted. 3 "" 9 By this technique, certain basic properties have been revealed for the x-ray inelastic scattering in the region where ka > 1.The experimental apparatus, arranged as shown in Fig.

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“…On the basis of th e correct eq (2) , Shimizu et al [7] proceeded to derive an extremely compli cated expression in closed form. A graphi cal integrati on of (2) was performed by Ramalin ga Reddy e t al.…”

mentioning

confidence: 99%

“…Here, du K/ du KN is the ratio R of the scatter-ing cross section of an electron bound in the K·shell to the Klein·Nishina prediction for an electron initially free and at rest. 3 On the basis of a nonrelativistic treatment and the incoherent scattering function approximation, Shimizu et aL [7] have given an analyti· cal expression for SK, which should be really valid only for small momentum transfers. But the same expression was used in the above· mentioned reports even at large scattering angles.…”

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Theoretical and experimental Compton scattering cross sections at 1.12 MeV in the case of strongly bound K-shell electrons

Prasad¹,

Kane²

1974

J. RES. NATL. BUR. STAN. SECT. A.

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Me asure me nt s a re re po rt ed for th e diffe re ntial c ross sec tion s for Co mpt o n sca tt e rin g of 1.12 Me V ga mma rays by th e K-s he ll e lec tro ns of tin , tantalum, gold, and th o rium . A few di screpa nc ies be t ween approxim ate th eo reti ca l ca lc u lation s and th e ex perim e ntal res ult s for diffe re nt e ne rgies are point e d ou t. Th e nee d for an e xact re lati vis ti c ca lc ul a ti o n is indi ca te d.Key word s : Co mpton sca tt e rin g; diffe re nti a l c ross section ; e lectro n bindin g; ga mma rays; K-s he ll ; photon s .Th e Compton scatte rin g of ga mma rays by s tron gly bound atomic K-shell ele ctron s has bee n studi ed experimentally a t 0. [12]. W e hav e give n preliminary reports on similar measurements mad e with a zinc-65 so urce at an e ne rgy of 1.12 MeV [13J.Motz and Mi ssoni [3J s ugges ted that th e res ults for large momentum transfers ca n be unders tood within the fram e work of an impuls e approximation. Recentl y, a jus tifi cation [14] of thi s approximation within th e framework of nonrelativi sti c quantum mechani cs has been given. If the target elec tron momentum p mak es angles a and a' with the mom e nta TI and TI' of the incide nt a nd th e scattered ph otons respectively, the e ne rgy k of the photon scatter ed through a n angle () is giv en by eq (1).where ko is the incid e nt photon e nergy, f3 is the ratio of the initial electron velocity to the veloci t y of light and E is the sum of the res t e nergy and the kinetic e ne rgy T of the targe t electron. In view of the virial th eore m , a convenient measure of T is taken 2 to be the bindin g energy of th e elec tron. Unfortu nately , in th e work of lau c h and R o hrl;~h [15], there was a *Wnrk s upported in pari by a g ra nt from tli e Na tiona l Bureau of S ta nd ards. W as hin g ton . D.C. undf!rt he I'L-480 p r-u~rallllll e. ** Presc nt address: Ph ysics Department. Indian I nstit ute ufT ec h nulogy, Pow ai. Bomha y-76. In dia.1 Fi gures in bracke ts ind ica te th e lit era ture referen ces at th e e nd of this paper.t At:curdin g tu the virial th eorem , the a verage ki ne ti c c ncrgy of an e lec t run bou nd by t he attrac ti ve Co ulomb pot e nti al in a n a tom turn s ou t to be e qu a l 10 the negative of half th e average p(Iten ti a l ('nergy. The rrfo rc. the average kine tic e nergy is the nega t ive uf th e su m of th e po te ntial and th e kin e ti c ene rgies. Thus. t he kin e tic c nc '·gy ma y be put e qual t o t he bind ing en ergy o f 1he e lectron. mi s prinl SO that a appeared in th e de nominator instead of a'. Th e final resu lt for th e cross section ( du K ) is obtained in te rm s of an average , as in eq. dO tmp .(2).( du K)where cf> is th e angle bet wee n th e planes formed by th e pairs of vectors (TI , p ) and (TI ', p ) a nd th e relativi s ti c expression for du/ dO in th e case of a free but fast electron has been giv e n by l a uc h and Rohrli c h.In th e calc ulation of Motz and Misso ni for 0.662 MeV , th e misprinted formula with Ct in ste'ld o...

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Incoherent Scattering of Gamma Rays byK-Shell Electrons

Cited by 45 publications

References 12 publications

Investigating Pseudoscalar and Scalar Dark Matter

Investigating Pseudoscalar and Scalar Dark Matter

X-Ray Compton-Raman Scattering from Atomic Inner-Shell Electrons

Theoretical and experimental Compton scattering cross sections at 1.12 MeV in the case of strongly bound K-shell electrons

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