Tubular electron beam ion source

Abstract

Electron beam ion sources (EBISs) provide the highest charge states of ion produced, high pulse ion currents, and a good emittance of an ion beam but an average ion current usually less than that for other sources of highly charged ions, for example, electron cyclotron resonance. The reason for that is an unusually small volume of electron–ion interaction, which is limited by the acceptable length of the source and by the electron beam perveance. To overcome the last limit while conserving all the advantages of the EBIS mentioned, the general idea of a tubular electron beam ion source (TEBIS) with an off-axis ion extraction is proposed. Construction of a TEBIS and its use in the normal or in the reflex mode of operation could increase an EBIS ion output 100–1000 times. The configuration of TEBIS and the current status of its development is described.

Electron beam ion sources in the reflex mode of operation (review and progress report) (invited)

“…[3][4][5][6][7][8][9][10][11][12] For this mode the specially designed electron gun and the electron reflector were constructed to accumulate multiply reflected electrons in a strong magnetic field. 13 As a surprisingly new result, the stepwise increase of the lifetime of accumulating electrons depending on the injection electron current was observed. In accordance to the present ideas, this increase is caused by the transition from the state of multiply reflected electrons to the electron string state.…”

Beam discharge excited by distributed virtual cathode

“…The result of this transition was called the beam squeezed state, which emphasizes one of its main fea tures: the state is detected by a specific phase diagram profile, when counterpropagating beams are squeezed so that they merge along the velocity axis in a certain region. Currently, various authors call the squeezed state differently: the electron string state [31], distrib uted VC [32], the slow state in contrast to the fast two flow state [33], emphasizing this or that property. In what follows, we use the term "distributed VC."…”

Low-energy electron ionization mass spectrometer for efficient detection of low mass species

“…In general, ionization efficiency can be improved by increasing the size of the ionizer, the electron density inside, and the duration that gas particles spend in that region-provided that the ions formed can still be extracted without significant losses. An established method of achieving these improvements is by using a solenoid magnetic field to confine the trajectories of the energetic electrons, [20][21][22][23] which can also extend the size of the ionization region and constrict the flow of gas through the ionizer. In a previous paper, 24 simulations examining the general principles of a solenoid ionizer, including the electron space charge formed inside, and how that can be used to contain and extract the ions formed have been reported.…”