PhysicaB366(2005)11–16 Adaptation of triple axis neutron spectrometer for SANS measurements using alumina samples at TRIGA reactor of Bangladesh F.U. Ahmed a ,I.Kamal a,Ã , S.M. Yunus a , T.K. Datta a , A.K. Azad a , A.K.M. Zakaria a , P.S. Goyal b a Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, P.O. Box 3787, Dhaka 1000, Bangladesh b Inter-University Consortium for DAE Facilities, Bhabha Atomic Research Center, Bombay 400 085, India Received 7 November 2003; received in revised form 7 March 2005; accepted 9 March 2005 Abstract Double crystal method known as Bonse and Hart’s technique has been employed to develop small angle neutron scattering(SANS)facilityonatripleaxisneutronspectrometeratTRIGAMarkII(3MW)researchreactorofAtomic Energy Research Establishment (AERE), Savar, Dhaka, Bangladesh. Two Si(111) crystals with very small mosaic spread 1minhavebeenusedforthispurpose.Atanincidentneutronwavelengthof1.24A ˚ ,thisdeviceisusefulfor SANSinthe Q rangebetween1.6  10 3 and10 1 A ˚ 1 .This Q rangeallowsinvestigatingparticlesizesandinterparticle correlationsonalengthscaleof 200A ˚ .ResultsofSANSexperimentsonthreealumina(Al 2 O 3 )samplesasperformed usingabovesetuparepresented.ItisseenthatAl 2 O 3 particles,indeed,scatterneutronsinregionsofsmallangles.Itis also seen that scattering is different for different samples showing that it changes with a change in particle size. r 2005 Published by Elsevier B.V. Pacs: 61.12.q; 61.12.Ex; 41.85.Si Keywords: Neutron spectrometer; SANS; Radius of gyration; Monochromator; Particle size 1. Introduction The basic understanding of physical materials and biological matters requires a detailed knowl- edge of the arrangement and dynamics of their atomsormolecules.Smallangleneutronscattering (SANS) is one of the powerful techniques that enable such information to be deduced at the ARTICLE IN PRESS www.elsevier.com/locate/physb 0921-4526/$-see front matter r 2005 Published by Elsevier B.V. doi:10.1016/j.physb.2005.03.045 Ã Corresponding author. Tel.: 88027701829; fax:88028613051. E-mail addresses: imtiaz_kamal126@yahoo.com, rnpd@dhaka.net (I. Kamal).