Metode variasional dalam mekanika Kuantum dan kbeberapa penerapannya dalam penentuan keadaan terikat dan parameter hamburan atomic = The Variational Method in Quantum Mechanics and Some of Its Applications in Finding ...

• Main Author: Perpustakaan UGM, i-lib
• Format: Article NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2005
• Subjects: Jurnal i-lib UGM
• Online Access: https://repository.ugm.ac.id/17563/; http://i-lib.ugm.ac.id/jurnal/download.php?dataId=322
• Institution: Universitas Gadjah Mada

The energy of the first excited state of the helium atom has been investigated theoretically and by numerical computation. The excited state is a bound state which has been calculated by assuming a trial wavefunction that depends on a set of free parameters. The proper choice of the trial wavefunction is determined by minimizing the energy expectation value. In the scattering problem, variational method is used for finding the target potential's scattering length via Hulthen-Kohn variational principle. The method to find the energy of the first excited state of helium atom uses the Newton-Raphson algorithm of finding roots. The result of the calculation gives a screened charge value 4- = 1, 017 e and the first excited energy of - 2, 1261(e2/a0) in gaussian unit. The scattering length of a low energy neutron by a spherical well potential of radius a = 2, 04 fm and reduced depth U0 = 0, 855 fm-2 arising from Hulthen-Kohn variational principle is solved analytically and then calculated numerically, giving approximate result of [a] 5, 3531 fin in agreement with the result of exact calculation method. Key words : variational method, Newton-Raphson algorithm, a trial wavefunction