New results on the absolute ion detection efficiencies of a microchannel plate

Oberheide, J.; Wilhelms, P; Zimmer, Manuel

doi:10.1088/0957-0233/8/4/001

Cited by 86 publications

(64 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The MCP gain is expected to be ∼ 2X larger under proton excitation in flight, as compared with the molecular nitrogen calibration beam, based on Fig. 2 of Oberheide et al (1997) and Fig. 1 of Furuya and Hatano (2002).…”

Section: Dis Calibration Facilitymentioning

confidence: 99%

See 1 more Smart Citation

Fast Plasma Investigation for Magnetospheric Multiscale

Pollock¹,

Moore²,

Jacques³

et al. 2016

Space Sci Rev

1,122

1,093

View full text Add to dashboard Cite

The Fast Plasma Investigation (FPI) was developed for flight on the Magnetospheric Multiscale (MMS) mission to measure the differential directional flux of magnetospheric electrons and ions with unprecedented time resolution to resolve kinetic-scale plasma dynamics. This increased resolution has been accomplished by placing four dual 180-degree top hat spectrometers for electrons and four dual 180-degree top hat spectrometers for ions around the periphery of each of four MMS spacecraft. Using electrostatic fieldof-view deflection, the eight spectrometers for each species together provide 4pi-sr field-ofview with, at worst, 11.25-degree sample spacing. Energy/charge sampling is provided by swept electrostatic energy/charge selection over the range from 10 eV/q to 30000 eV/q. The eight dual spectrometers on each spacecraft are controlled and interrogated by a single block redundant Instrument Data Processing Unit, which in turn interfaces to the observatory's Instrument Suite Central Instrument Data Processor. This paper describes the design of FPI, its ground and in-flight calibration, its operational concept, and its data products.

show abstract

Section: Dis Calibration Facilitymentioning

confidence: 99%

“…The detection efficiency should also be larger for protons than for molecular nitrogen, based on Fig. 3 of Oberheide et al (1997). Both effects will be quantified with inflight commissioning/calibration procedures.…”

Section: Dis Calibration Facilitymentioning

confidence: 99%

Fast Plasma Investigation for Magnetospheric Multiscale

Pollock¹,

Moore²,

Jacques³

et al. 2016

Space Sci Rev

1,122

1,093

View full text Add to dashboard Cite

show abstract

“…The versatility of the MCP makes it a gain-producing element of choice for energetic particles (ionic and neutral species), electrons, X-rays, and from UV to IR when used with appropriate photocathodes. The broad descriptive work of MCPs can be found in early work [5][6][7][8][9][10][11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Preliminary Demonstration of an IonCCD as an Alternative Pixelated Anode for Direct MCP Readout in a Compact MS-Based Detector

Hadjar

Fowler

Kibelka

et al. 2011

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

We report on the preliminary testing of a new position-sensitive detector (PSD) by combining a microchannel plate (MCP) and a charge-sensitive pixilated anode with a direct readout based on charge-coupled detector (CCD) technology, which will be referred to as IonCCD (Hadjar et al. , allowing it to be used directly behind an MC. This MCP-IonCCD configuration potentially obviates the need for electro-optical ion detector systems (EOIDs), which typically feature a relatively difficult-to-implement 5-kV power source as well as a phosphorus screen behind the MCP for conversion of electrons to photons prior to signal generation in a photosensitive CCD. Thus, the new system (MCP-IonCCD) has the potential to be smaller, simpler, more robust, and more cost efficient than EOID-based technologies in many applications. The use of the IonCCD as direct MCP readout anode, as opposed to its direct use as an ion detector, will benefit from the instant three-tofour-order-of-magnitude gain of the MCP with virtually no additional noise. The signal/noise gain can be used for either sensitivity or speed enhancement of the detector. The speed enhancement may motivate the development of faster IonCCD readout speeds (currently at 2.7 ms) to achieve the 2 kHz frame rate for which the IonCCD chip was designed, a must for transient signal applications. The presented detector exhibits clear potential not only as a trace analysis detector in scan-free mass spectrometry and electron spectroscopy but also as a compact detector for photon and particle imaging applications.

show abstract

“…The efficiencies are 50% for ions [15] and 85% for electrons. The magnitude of the applied electric field is calibrated through field ionization of Rydberg atoms [16].…”

mentioning

confidence: 96%

Creation of an Ultracold Neutral Plasma

et al. 1999

View full text Add to dashboard Cite

We report the creation of an ultracold neutral plasma by photoionization of laser-cooled xenon atoms. The charge carrier density is as high as 2 × 10 9 cm −3 , and the temperatures of electrons and ions are as low as 100 mK and 10 µK, respectively. Plasma behavior is evident in the trapping of electrons by the positive ion cloud when the Debye screening length becomes smaller than the size of the sample. We produce plasmas with parameters such that both electrons and ions are strongly coupled.The study of ionized gases in neutral plasma physics spans temperatures ranging from 10 16 K in the magnetosphere of a pulsar to 300 K in the earth's ionosphere [1]. At lower temperatures the properties of plasmas are expected to differ significantly. For instance, three-body recombination which is prevalent in high temperature plasmas, should be suppressed [2]. If the thermal energy of the particles is less than the Coulomb interaction energy, the plasma becomes strongly coupled, and the usual hydrodynamic equations of motion and collective mode dispersion relations are no longer valid [3]. Strongly coupled plasmas are difficult to produce in the laboratory and only a handful of examples exist [4], but such plasmas do occur naturally in astrophysical systems.In this work we create an ultracold neutral plasma with an electron temperature as low as T e = 100 mK, an ion temperature as low as T i = 10 µK, and densities as high as n = 2×10 9 cm −3 . We obtain this novel plasma by photoionization of laser-cooled xenon atoms. Within the experimentally accessible ranges of temperatures and densities both components can be simultaneously strongly coupled. A simple model describes the evolution of the plasma in terms of the competition between the kinetic energy of the electrons and the Coulomb attraction between electrons and ions. A numerical calculation accurately reproduces the data.Photoionization and laser-cooling have been used before in plasma experiments. Photoionization in a 600 K Cs vapor cell produced a plasma with T e ≥ 2000 K [5], and a strongly coupled non-neutral plasma was created by laser-cooling magnetically trapped Be + ions [6]. A plasma is often defined as an ionized gas in which the charged particles exhibit collective effects [7]. The length scale which divides individual particle behavior and collective behavior is the Debye screening length λ D . It is the distance over which an electric field is screened by redistribution of electrons in the plasma, and is given by λ D = ǫ 0 k B T e /e 2 n. Here, ǫ 0 is the electric permittivity of vacuum, k B is the Boltzmann constant, and e is the elementary charge. An ionized gas is not a plasma unless the Debye length is smaller than the size of the system [7]. In our experiment, the Debye length can be as low as 500 nm, while the size of the sample is σ ≈ 200 µm. The condition λ D < σ for creating a plasma is thus easily fulfilled.The atomic system we use is metastable xenon in the 6s [3/2] 2 state. This state has a lifetime of 43 s [8] and can be treated as the groun...

show abstract

New results on the absolute ion detection efficiencies of a microchannel plate

Cited by 86 publications

References 8 publications

Fast Plasma Investigation for Magnetospheric Multiscale

Fast Plasma Investigation for Magnetospheric Multiscale

Preliminary Demonstration of an IonCCD as an Alternative Pixelated Anode for Direct MCP Readout in a Compact MS-Based Detector

Creation of an Ultracold Neutral Plasma

Contact Info

Product

Resources

About