Hyper excited states and de-excitation Three states of Helium atom - normal, hyper excited and normal excited states When sufficient energy is available both the electrons in the ground state of helium may be excited. Such excitation is called hyper excited. When a helium atom is hyper excited, the process of de-excitation takes place in two ways. In the first way one of the electrons in the hyper excited state jumps to the inner orbits either directly or step by step with intermediate energy levels. Then the second electron follows its own de-excitation. In the second way called hyper de-excitation both the electrons jumps to the lower energy level. The hyper excitation of helium is possible in dense stars enriched with helium at high temperature which provide more probability for hyper excitation to happen. Since the instability of the atomic system is increased many-fold, the hyper de-excitation will be faster than the normal de-excitation. The hyper excitation and de-excitation are not possible in hydrogen atom, a single electron system. Hyper excitation and Hyper de-excitation Total energy of helium in its nth hyper excited state is given by - (1/n^2)(49/8) (e^2/2Kao). In two different hyper excited states with n = n1 and n2,the total energies are - (1/n1^2)(49/8)(e^2/2Kao)and - (1/n2^2)(49/8) (e^2/2Kao) respectively. During hyper de-excitation, both the electrons simultaneously jump into to any inner or innermost orbit. In hyper de-excitation between any two states, the transition energy ΔE is given by (49/8) (e^2/2Kao)[(1/n1^2) - (1/n2^2)] = 83.269 [(1/n1^2) - (1/n2^2)] eV. Since λ = hc/ΔE, where ΔE is in joules, the corresponding wavelength of radiation emitted in any transition is given by λn2* → n1* is 12.4 x 10^-7/(49/8) (e^2/2Kao) [(1/n1^2) (1/n2^2)]m. The star (*) is used to represent the hyper excited state. Using this formula, the transition energy and the corresponding wavelength of radiation emitted can be predicted. The energy of transition and the wavelength of radiation emitted in various hyper de-excitation are given in Table Table. Hyper de-excitations and wavelengths in helium ............................................................................... transition energy wavelength . eV nm ------------........................................... n2* → n1* 62.452 19.85 n3*→ n1* 74.017 16.75 n4* → n1* 78.065 15.88 n3* → n2* 11.565 117.22 n4* → n2* 15.613 79.42 n4* → n3* 4.048 306.32 n5* → n3* 5.921 209.42 n6* → n3* 6.939 178.70 n5* → n4* 1.874 661.69 n6* → n4* 2.891 428.91 ........................................................ The ultraviolet wavelength in the helium spectrum is most notably characterized by the strong atomic line at 58.4 nm. The strongest UV lines for astrophysical observation are at 30.38 nm and 58.43 nm. The spectroscopical study in UV region of helium atom shows that hyper excitation and hyper de-excitation have very little probability to happen under normal situations. In hot stars enriched with helium, hyper de-excitation may be one of the causes for the emission of UV radiation. Helium has several spectral lines in the ultraviolet (UV) region, which are defined as having wavelengths shorter than approximately 400 nm. Key UV lines for neutral helium include lines around 396.5 nm and 388.9 nm. It shows that the cause of transition in helium atom liberating energy in the UV radiation is not hyper de-excitation