東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Methods for Plasma Stabilization and...

Carruth, Celeste.

Linked to FindBook

Google Book

Amazon

博客來

Methods for Plasma Stabilization and Control to Improve Antihydrogen Production.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Methods for Plasma Stabilization and Control to Improve Antihydrogen Production./
Author:	Carruth, Celeste.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2018,
Description:	122 p.
Notes:	Source: Dissertations Abstracts International, Volume: 80-06, Section: B.
Contained By:	Dissertations Abstracts International80-06B.
Subject:	Plasma physics. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10930837
ISBN:	9780438643765

Methods for Plasma Stabilization and Control to Improve Antihydrogen Production.
Carruth, Celeste.

Methods for Plasma Stabilization and Control to Improve Antihydrogen Production. - Ann Arbor : ProQuest Dissertations & Theses, 2018 - 122 p.

Source: Dissertations Abstracts International, Volume: 80-06, Section: B.

Thesis (Ph.D.)--University of California, Berkeley, 2018.

This item must not be sold to any third party vendors.

The ALPHA (Antihydrogen Laser Physics Apparatus) collaboration creates and performs precise measurements on antihydrogen to test Charge-Parity-Time (CPT) symmetry. Prior to creating antihydrogen we must prepare the antiproton and positron plasmas to have optimal and repeatable parameters. This thesis presents the development of a new method to simultaneously control the number of particles and plasma density of lepton plasmas, developments that increased our antihydrogen trapping rate, precision physics measurements performed on antihydrogen, and other plasma studies still under development. The method to stabilize the number of particles was based on a zero-temperature plasma model, which states that the plasma's on-axis self potential and density uniquely define a plasma. It is the combination of two previously existing techniques, radial compression in the Strong Drive Regime (SDR) with Evaporative Cooling (EVC), thus we called it SDREVC. Experimentally this method has proven to be very robust in delivering nearly identical plasmas, and theoretical calculations applying a finite temperature plasma model indicate that temperature effects in our operating regime are insignificant. The development took place in ALPHA's Penning-Malmberg traps, and consisted of designing and testing potential well shapes that allowed the compression and evaporation to occur simultaneously. The standard deviation in particle number of our initial load of positrons in 2016 was 24%, a fluctuation which was previously uncontrolled, but the standard deviation after SDREVC amounted to only 3%. After implementing SDREVC in our experimental routines, the stability made it possible to optimize plasma manipulations for antihydrogen production runs and increase our antihydrogen trapping rate by approximately a factor of 20. This increase in the trapping rate played a major role in our recent measurements of the hyperfine transition and 1S-2S spectroscopy of antihydrogen, and the 1S-2S spectroscopy measurement is now one of the most precise tests of CPT symmetry.

ISBN: 9780438643765Subjects--Topical Terms:

3175417
Plasma physics.

Methods for Plasma Stabilization and Control to Improve Antihydrogen Production.
LDR:03133nmm a2200313 4500 001 2210551
005 20191121124237.5
008 201008s2018 ||||||||||||||||| ||eng d
020 $a 9780438643765
035 $a (MiAaPQ)AAI10930837
035 $a (MiAaPQ)berkeley:18265
035 $a AAI10930837
040 $a MiAaPQ $c MiAaPQ
100 1 $a Carruth, Celeste. $3 3437690
245 1 0 $a Methods for Plasma Stabilization and Control to Improve Antihydrogen Production.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2018
300 $a 122 p.
500 $a Source: Dissertations Abstracts International, Volume: 80-06, Section: B.
500 $a Publisher info.: Dissertation/Thesis.
500 $a Advisor: Fajans, Joel.
502 $a Thesis (Ph.D.)--University of California, Berkeley, 2018.
506 $a This item must not be sold to any third party vendors.
520 $a The ALPHA (Antihydrogen Laser Physics Apparatus) collaboration creates and performs precise measurements on antihydrogen to test Charge-Parity-Time (CPT) symmetry. Prior to creating antihydrogen we must prepare the antiproton and positron plasmas to have optimal and repeatable parameters. This thesis presents the development of a new method to simultaneously control the number of particles and plasma density of lepton plasmas, developments that increased our antihydrogen trapping rate, precision physics measurements performed on antihydrogen, and other plasma studies still under development. The method to stabilize the number of particles was based on a zero-temperature plasma model, which states that the plasma's on-axis self potential and density uniquely define a plasma. It is the combination of two previously existing techniques, radial compression in the Strong Drive Regime (SDR) with Evaporative Cooling (EVC), thus we called it SDREVC. Experimentally this method has proven to be very robust in delivering nearly identical plasmas, and theoretical calculations applying a finite temperature plasma model indicate that temperature effects in our operating regime are insignificant. The development took place in ALPHA's Penning-Malmberg traps, and consisted of designing and testing potential well shapes that allowed the compression and evaporation to occur simultaneously. The standard deviation in particle number of our initial load of positrons in 2016 was 24%, a fluctuation which was previously uncontrolled, but the standard deviation after SDREVC amounted to only 3%. After implementing SDREVC in our experimental routines, the stability made it possible to optimize plasma manipulations for antihydrogen production runs and increase our antihydrogen trapping rate by approximately a factor of 20. This increase in the trapping rate played a major role in our recent measurements of the hyperfine transition and 1S-2S spectroscopy of antihydrogen, and the 1S-2S spectroscopy measurement is now one of the most precise tests of CPT symmetry.
590 $a School code: 0028.
650 4 $a Plasma physics. $3 3175417
690 $a 0759
710 2 $a University of California, Berkeley. $b Physics. $3 1671059
773 0 $t Dissertations Abstracts International $g 80-06B.
790 $a 0028
791 $a Ph.D.
792 $a 2018
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10930837