Simulation studies of the behavior of positrons in a microtrap with long aspect ratio

Narimannezhad, Alireza; Baker, Christopher J. O.; Weber, Marc H.; Xu, Jing; Lynn, Kelvin G.

doi:10.48550/arxiv.1301.0030

Cited by 2 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Discordant values of them cause a large numerical instability. The choice of values for the parameters with the largest influence on numerical noise is discussed in another study [1]. The initial uniform plasma radius is 1/ √ 3 of the microtrap radius and its positron density is equal to 4.8×10 11 cm −3 .…”

Section: B Dies and Magnetic Field Misalignmentsmentioning

confidence: 99%

“…

…”

mentioning

confidence: 99%

“…Since the axial confinement is assured inside the potential well between two end caps of microtrap, the plasma is lost only by radial transport across the magnetic field. Radial transport is constrained by conservation of the total canonical angular momentum of the positrons; this implies that torques from outside the plasma are required for plasma expansion and loss [1]. Experiments have established that the containment times depend strongly on the length of the plasma column [4] as longer plasmas experience higher levels of field and geometry asymmetries.…”

mentioning

confidence: 99%

“…Therefore, it is crucial to fabricate the microtraps of minimal geometry errors and asymmetries. Analytical calculations and simulation results have shown that the trapped positron density is proportional to the inverse square of the trap radius [1]. As we go to smaller and smaller radii microtraps, the fabrication of the trap as well as the magnetic field alignment become more challenging.…”

mentioning

confidence: 99%

“…2. Computationally, more than one hundred million positrons can be trapped in one tube of this dimension (100 µm diameter and 100 mm length) when the applied electric field to the tube ends in only 10 V [1]. Thus, the entire trap would hold more than 10 12 positrons.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Fabrication of High Aspect Ratio Micro-Penning-Malmberg Gold Plated Silicon Trap Arrays

Narimannezhad¹,

Jennings²,

Weber³

et al. 2013

Preprint

Self Cite

View full text Add to dashboard Cite

Acquiring a portable high density charged particles trap might consist of an array of micro-Penning-Malmberg traps (microtraps) with substantially lower end barriers potential than conventional Penning-Malmberg traps [1]. We report on the progress of the fabrication of these microtraps designed for antimatter storage such as positrons. The fabrication of large length to radius aspect ratio (1000 : 1) microtrap arrays involved advanced techniques including photolithography, deep reactive ion etching (DRIE) of silicon wafers to achieve through-vias, gold sputtering of the wafers on the surfaces and inside the vias, and thermal compression bonding of the wafers. This paper describes the encountered issues during fabrication and addresses geometry errors and asymmetries. In order to minimize the patch effects on the lifetime of the trapped positrons, the bonded stacks were gold electroplated to achieve a uniform gold surface. We show by simulation and analytical calculation that how positrons confinement time depends on trap imperfections.

show abstract

Section: B Dies and Magnetic Field Misalignmentsmentioning

confidence: 99%

“…

…”

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Fabrication of High Aspect Ratio Micro-Penning-Malmberg Gold Plated Silicon Trap Arrays

Narimannezhad¹,

Jennings²,

Weber³

et al. 2013

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

Study of Conduction Cooling Effects in Long Aspect Ratio Penning-Malmberg Micro-Traps

Khamehchi¹,

Baker²,

Weber³

et al. 2013

Preprint

View full text Add to dashboard Cite

A first order perturbation with respect to velocity has been employed to find the frictional damping force imposed on a single moving charge due to a perturbative electric field, inside a long circular cylindrical trap. We find that the electric field provides a cooling effect, has a tensorial relationship with the velocity of the charge. A mathematical expression for the tensor field has been derived and numerically estimated. The corresponding drag forces for a charge moving close to the wall in a cylindrical geometry asymptotically approaches the results for a flat surface geometry calculated in the literature. Many particle conduction cooling power dissipation is formulated using the single particle analysis. Also the cooling rate for a weakly interacting ensemble is estimated. It is suggested that a pre-trap section with relatively high electrical resistivity can be employed to cool down low density ensembles of electrons/positrons before being injected into the trap. For a micro-trap with tens of thousands of micro-tubes, hundreds of thousands of particles can be cooled down in each cooling cycle. For example, tens of particles per micro-tube in a 5cm long pre-trap section with the resistivity of 0.46Ωm and the micro-tubes of radius 50µm can be cooled down with the time constant of 106µs.

show abstract

Simulation studies of the behavior of positrons in a microtrap with long aspect ratio

Cited by 2 publications

References 0 publications

Fabrication of High Aspect Ratio Micro-Penning-Malmberg Gold Plated Silicon Trap Arrays

Fabrication of High Aspect Ratio Micro-Penning-Malmberg Gold Plated Silicon Trap Arrays

Study of Conduction Cooling Effects in Long Aspect Ratio Penning-Malmberg Micro-Traps

Contact Info

Product

Resources

About