EP2521427A1 - Procédé et dispositif de formation d'impulsions d'ions à crêtes aplanies issus de sources d'ions à faisceau d'électrons - Google Patents

Procédé et dispositif de formation d'impulsions d'ions à crêtes aplanies issus de sources d'ions à faisceau d'électrons Download PDF

Info

Publication number
EP2521427A1
EP2521427A1 EP11165031A EP11165031A EP2521427A1 EP 2521427 A1 EP2521427 A1 EP 2521427A1 EP 11165031 A EP11165031 A EP 11165031A EP 11165031 A EP11165031 A EP 11165031A EP 2521427 A1 EP2521427 A1 EP 2521427A1
Authority
EP
European Patent Office
Prior art keywords
ion
trap
extraction
potential
electron beam
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP11165031A
Other languages
German (de)
English (en)
Inventor
Frank Dr.-Ing. Großmann
Günter PD Dr.rer.nat.habil. Zschornack
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dreebit GmbH
Original Assignee
Dreebit GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dreebit GmbH filed Critical Dreebit GmbH
Priority to EP11165031A priority Critical patent/EP2521427A1/fr
Publication of EP2521427A1 publication Critical patent/EP2521427A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H7/00—Details of devices of the types covered by groups H05H9/00, H05H11/00, H05H13/00
    • H05H7/02—Circuits or systems for supplying or feeding radio-frequency energy
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H7/00—Details of devices of the types covered by groups H05H9/00, H05H11/00, H05H13/00
    • H05H7/08—Arrangements for injecting particles into orbits

Definitions

  • the invention relates to a method for forming roof ion pulses from electron beam ion sources and a device suitable for this purpose.
  • Electron cyclotron resonance ECR ion sources in conjunction with a beam chopper are currently commonly used as ion sources for medical particle therapy equipment. These sources provide ions such as C 4+ with sufficient intensity, which then have to be deionized to C 6+ for efficient acceleration in a synchrotron.
  • Fully ionized carbon atoms (C 6+ ) are directly supplied by electron beam ion sources, also referred to as EBIS Electron Beam Ion Source.
  • the ion pulses extracted from electron beam ion sources show a pulse shape that often approaches an asymmetric Gaussian pulse.
  • This pulse shape is produced by the switching process of the ion trap inherent in an electron beam ion source and has virtually the same qualitative shape for all previously known electron beam ion sources.
  • ion pulses in the range of about two ⁇ s are required in a "single-turn" injection
  • the "multi-turn" injection places special demands on the pulse shape to be implemented at the output of the ion source. Roof ion pulses over a width of several tens of ⁇ s are required, whereby it depends on a corresponding edge steepness and the highest possible stability of the pulse roof over the entire pulse length.
  • the object of the invention is to provide a technical solution and a method for how over a wide time base range roof ion pulses can be formed, or how generally can be influenced on the pulse shape of the extracted ion pulses.
  • the aim is to find a solution with which peak ion pulses can be formed during the extraction of ions from EBIS ion sources in order to meet the requirements of different accelerator regimes.
  • the extraction-side trap potential is timed to U 0 + U B1 for ion collection and lowered to U 0 -U B2 for ion extraction and the trap potential is adjusted to the ion energy distribution in the EBIS trap.
  • the opening characteristic of the trap is designed such that the lowering of the extraction-side trap potential follows a temporally falling functional course of U B.
  • the conception of the invention consists in the fact that the lowering of the extraction-side trapping potential from U 0 + U B1 to U 0 -U B2 does not take place in the range of a few microseconds, as in the prior art, but that the reduction takes place over a longer period of time the lowering is not quasi-discrete by a single switching operation, but a temporally falling function of the potential U B follows.
  • the time for the switching operation thus usually corresponds to a multiple of the switching time of traps according to the prior art.
  • the trapping potential follows the temporal functional course of U B as a continuous voltage drop.
  • the trap potential follows the temporal function course of U B in several discrete steps.
  • the method is further improved by the fact that a smoothing of the course takes place.
  • a device for forming roof ion pulses from an electron beam ion source is characterized in that a pulse generator for controlling the trap potential is arranged on an extraction-side drift tube of a drift tube ensemble and is designed such that the extraction-side trap potential is timed to U 0 + U B1 for ion collection and to Ion extraction on U 0 -U B2 lowered and the opening characteristic of the trap is designed such that the reduction of the extraction-side trap potential follows a time-decreasing function of U B.
  • the device is further developed in that an RC element is arranged for smoothing the control pulse.
  • the invention relates to a new type of source control, the essence of which is the extraction-side trap potential of the electron beam ion source, ie the switching of U 0 + U B1 to U 0 -U B2 , time-controlled by technical means and adapted to the ion energy distribution in the EBIS Trap to control. That this is necessary follows from the consideration that the ions in the trap when opening the trap have a certain energy distribution and depending on their current direction of motion must fly through a distance of twice the trap length L at most. This is equivalent to an additional time of flight through the trap region and is reflected in the width of the extracted ion pulse.
  • the measures according to the invention make it possible to design the opening characteristic of the trap in such a way that the trap potential follows a temporal functional course of U B , as a result of which roofing ion pulses can be generated. According to one embodiment of the invention, this is done with a special pulse generator and according to an advantageous embodiment of the invention with a special pulse generator connected to an additional RC smoothing of the control pulse.
  • the essence of the invention consists in a reduction of the trap potential over time after a functional course, it is logical that this function course can also be achieved by other technical solutions than the special pulse generator, for example electronically.
  • the course of the reduction of the trap potential can be realized both via digital, discrete voltage reduction, as well as analog predetermined voltage curves.
  • the ion sources according to the invention can be used for medical hadron particle therapy, which currently takes place primarily with protons and carbon ions.
  • the invention is of importance for various forms of medical particle therapy, such as synchrotron-based particle therapy, particle therapy with CYCLINACs, particle therapy with compact accelerator solutions and particle therapy with Rapid Cycling Medical Synchrotrons RCMS.
  • Electron beam ion sources represent a new generation of ion sources for medical particle therapy accelerators that have heretofore, but not exclusively, used synchrotrons.
  • the intensities can be increased so that an application for particle therapy systems with all the advantages of an electron beam ion source is possible.
  • These sources are commercially available and their use can significantly reduce the cost of radiation therapy equipment injection side.
  • electron beam ion sources for medical applications are the purity of the ion pulse, the long-term stability of the source, the excellent beam emittance and the fact that virtually all stable elements of the periodic table can be used.
  • these sources can deliver ion pulses with a pulse width of 1 ⁇ s up to 100 ⁇ s.
  • the electron beam ion sources according to the invention satisfy the requirements with respect to the ion currents and time structures which have to be set to a "multi-turn" or a "single-turn" injection for injection into a synchrotron or into a rapid cycling synchrotron.
  • Classical pulse shaping in EBIS ion sources is only affected by the energy distribution of the ions in the trap, the transit time of the ions in the source volume, and the quality of the U B circuit.
  • the advantage of an EBIS operated according to the invention is that it actively influences the formation of the output ion pulses by realizing a special switching pulse shaping for U B. This makes it possible to adapt the ion extraction pulses to the technical requirements of accelerators, such as the multi-turn injection into a synchrotron or a Rapid Cycling Medical Synchrotron.
  • both the shape and the rising edges of these pulses can be influenced for optimal compatibility with subsequent accelerator structures.
  • the extracted from an EBIS ion pulse can also be shortened, as may be for example for the "single-turn" ion injection into a synchrotron of importance. This is always essential when it comes to EBIS with trap lengths of 10 cm or more, as these trap structures are generally segmented several times. Thus, it can be achieved via an individual activation of the drift tube segments that the ions can collect in the extraction-side part of the trap and then be extracted in a short ⁇ s-second pulse.
  • Fig. 1 The functional principle of an EBIS is based on the fact that atoms in a high-density electron beam 11 are ionized by successive electron impact ionization.
  • the electron beam 11 emitted from a highly-emission cathode is magnetically compressed in the magnetic field of an EBIS 1 and can thus act as an efficient ionization medium. Since the ionization process takes place successively in the electron beam 11, a certain dwell time of the ions 12 in the electron beam 11 is required, that is, a time-controllable ion trap must be realized. This is achieved by shooting the electron beam 11 through a drift tube ensemble 3 provided with electrical potentials. In its simplest form, the Driftröhrenensemble 3, as in Fig.
  • the ion trap in the EBIS 1 is realized radially by the negative space charge potential of the electron beam 11 and axially by the application of special positive potentials at the two outer drift tube sections.
  • the radial confinement potential can be regarded as constant over the region of the central drift tube section over the z-direction along the beam axis.
  • the characteristic working cycle of an EBIS 1 is based on a drift tube ensemble 3, consisting of three drift tubes 3.1, 3.2, 3.3, in Fig. 2 shown.
  • a drift tube ensemble 3 consisting of three drift tubes 3.1, 3.2, 3.3, in Fig. 2 shown.
  • an electron current is generated by the cathode 2 is heated with the current I CH at a voltage U H.
  • the cathode 2 is additionally at a potential -U c .
  • the thus formed electron beam follows the z-axis and enters the ionization zone, which is surrounded by three drift tube segments 3.1, 3.2, 3.3.
  • the cathode side Drift tube 3.1 acts as an anode at the same time.
  • the electron energy is varied by setting U 0 .
  • U A generates the axial trapping potential for the ions.
  • the voltage at the extraction-side drift tube 3.3 is optionally raised to U 0 + U B1 for ion collection, or lowered to U 0 -U B2 for ion extraction.
  • the electron / ion beam in the electron collector 4 is separated from the electron component and the further ion extraction takes place with the aid of an extraction electrode 5 at the potential U EX .
  • the movement of the ions in the trap is in Fig. 4 shown.
  • the concept of the invention consists in a new type of source control, in which the extraction-side trapping potential of the EBIS, ie the switching from U 0 + U B1 to U 0 -U B2 , is time-controlled by technical means and adapted to the ion energy distribution in the EBIS trap ,
  • the ions 12 in the trap have a certain energy distribution when the trap is opened and, depending on their current direction of movement, must travel at most a distance of twice the trap length L, as in FIG Fig. 4 is shown. Where L is the trap length and the maximum distance is twice the trap length, two times L. This is equivalent to an additional one Flight time through the trap region and reflected in the width of the extracted ion pulse again.
  • Fig. 5a shows a prior art source circuit as used to generate pulses as in FIG Fig. 3 shown, is suitable.
  • the inventive electrical wiring of an EBIS for the purpose of a roof ion pulse generation is generalizing in Fig. 5b and Fig. 5c shown.
  • Fig. 5b shows an additional control of U B by a special pulse generator 6 according to the teachings of the invention.
  • a special pulse generator 6 different circuits can be configured, which either enable a continuous programmable voltage drop (switching pulse shape) or approximate this voltage curve in discrete steps, if necessary according to Fig. 5c by means of an RC element of resistor 7 and capacitor 8 is still smoothed.
  • FIG. 6 the opening characteristic 10 and roof ion pulses 13 according to the invention are shown as generated C 4+ roof ion pulses, also referred to as roof ion pulses, as they are with a generator with ten discrete voltage steps according to a functional diagram according to FIG Fig. 7 , coupled with RC smoothing.
  • FIG. 7 A characteristic of such a procedure EBIS circuit for the short-term extraction is in Fig. 7 for an eight-segmented drift tube ensemble 3 shown.
  • Figure 8 shows as an embodiment of an arbitrary signal generator 6, which is isolated on a voltage of, for example, 20 kV and which generates an arbitrarily configurable signal in the range of 0 to -100V after a trigger signal.
  • the voltage curve can be programmed in time steps of 100 ns or other time steps.
  • Such a generator 6 can be used to generate the in Fig. 6 illustrated roof ion pulses are used, but also other electronic solutions are possible.
  • the one shown here Solution has exemplary character, significantly more voltage levels are possible, as well as a generated via a function generator continuous switching curve for U B.
  • Fig. 9 shows the potential U B as a time-dependent function over the switching time t.
  • the opening characteristic of the prior art is shown schematically by the reference numeral 9 and discretely follows a switching from U 0 + B 1 to U 0 -B 2 in one step.
  • Fig. 10 different variants for an opening characteristic according to the teachings of the invention are shown.
  • the process of Fig. 10a follows a non-linear decrease in potential, the curve of Fig. 10b shows a linear decay and the curve of Fig. 10c shows a decrease in several discrete steps.
  • the switching times according to the teachings of the invention are a multiple of the switching times according to the prior art.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Particle Accelerators (AREA)
EP11165031A 2011-05-06 2011-05-06 Procédé et dispositif de formation d'impulsions d'ions à crêtes aplanies issus de sources d'ions à faisceau d'électrons Withdrawn EP2521427A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP11165031A EP2521427A1 (fr) 2011-05-06 2011-05-06 Procédé et dispositif de formation d'impulsions d'ions à crêtes aplanies issus de sources d'ions à faisceau d'électrons

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP11165031A EP2521427A1 (fr) 2011-05-06 2011-05-06 Procédé et dispositif de formation d'impulsions d'ions à crêtes aplanies issus de sources d'ions à faisceau d'électrons

Publications (1)

Publication Number Publication Date
EP2521427A1 true EP2521427A1 (fr) 2012-11-07

Family

ID=44654547

Family Applications (1)

Application Number Title Priority Date Filing Date
EP11165031A Withdrawn EP2521427A1 (fr) 2011-05-06 2011-05-06 Procédé et dispositif de formation d'impulsions d'ions à crêtes aplanies issus de sources d'ions à faisceau d'électrons

Country Status (1)

Country Link
EP (1) EP2521427A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102015104213A1 (de) 2015-03-20 2016-09-22 Dreebit Gmbh Vorrichtung und Verfahren zur Erzeugung und Aussendung eines ladungs- und massenseparierten Ionenstrahls variabler Energie
CN112616237A (zh) * 2020-12-07 2021-04-06 中国科学院近代物理研究所 一种产生准正弦波脉冲电子束的方法、系统和可读介质

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
HOLLOWAY M ET AL: "Injector Electronics for Multi-Turn Operation of the University of Maryland Electron Ring", PARTICLE ACCELERATOR CONFERENCE, 2005. PAC 2005. PROCEEDINGS OF THE KNOXVILLE, TN, USA 16-20 MAY 2005, PISCATAWAY, NJ, USA,IEEE, 16 May 2005 (2005-05-16), pages 3952 - 3954, XP010892043, ISBN: 978-0-7803-8859-8, DOI: 10.1109/PAC.2005.1591680 *
KENTSCH ET AL.: "Short time ion pulse extraction from the Dresden electron beam ion trap", REVIEW OF SCIENTIFIC INSTRUMENTS, vol. 81, no. 2, February 2010 (2010-02-01), USA, pages 02A507-1 - 02A507-3, XP002660508, ISSN: 0034-6748 *
OVSYANNIKOV ET AL.: "Untersuchungen zur Erzeugung von niedrig-Z-Ionen für die medizinische Teilchentherapie", 14 March 2011 (2011-03-14), XP002660510, Retrieved from the Internet <URL:http://www.dpg-verhandlungen.de/year/2011/conference/dresden/part/st/session/2> [retrieved on 20111004] *
vol. FB303EN - Version 03/2011, March 2011 (2011-03-01), Dresden, DE, pages 1 - 36, XP002660507, Retrieved from the Internet <URL:http://www.dreebit.com/download/electron_and_ion_beam_technologies.pdf> [retrieved on 20111004] *
ZSCHORNACK ET AL.: "First experiments with the Dresden EBIS-SC", JOURNAL OF INSTRUMENTATION, vol. 5, no. 8, August 2010 (2010-08-01), UK, pages C08012-1 - C08012-14, XP002660509, ISSN: 1748-0221 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102015104213A1 (de) 2015-03-20 2016-09-22 Dreebit Gmbh Vorrichtung und Verfahren zur Erzeugung und Aussendung eines ladungs- und massenseparierten Ionenstrahls variabler Energie
CN112616237A (zh) * 2020-12-07 2021-04-06 中国科学院近代物理研究所 一种产生准正弦波脉冲电子束的方法、系统和可读介质
CN112616237B (zh) * 2020-12-07 2023-08-11 中国科学院近代物理研究所 一种产生准正弦波脉冲电子束的方法、系统和可读介质

Similar Documents

Publication Publication Date Title
DE69906699T2 (de) Quadrupl ionenfalle und flugzeitmassenspektrometer mit einer solchen ionen falle
DE112009001360B4 (de) Massenspektrometer mit Spannungsstabilisierung mittels Leerbetrieb
EP1872372B1 (fr) Cylindre creux soumis a l&#39;action d&#39;un rayonnement laser, utilise en tant que lentille pour faisceaux d&#39;ions
DE10311659A1 (de) Vorrichtung und Verfahren zur optimierten elektrohydralischen Druckpulserzeugung
DE102014001591A1 (de) Teilchenbeschleuniger und medizinisches Gerät
WO2011104077A2 (fr) Accélérateur de particules chargées
EP2164309B1 (fr) Procédé et dispositif pour commander une décharge à cathode creuse
DE10325581B4 (de) Verfahren und Vorrichtung für das Einspeichern von Ionen in Quadrupol-Ionenfallen
DE1789071B1 (de) Vorrichtung zur Untersuchung plasmaphysikalischer Vorgaenge
DE3705165A1 (de) Mit entladungserregung arbeitende laservorrichtung fuer kurze impulse
DE19650542A1 (de) Dreidimensionales Quadrupolmassenspektrometer
DE69029150T2 (de) Entladungsangeregte Impulslaservorrichtung
DE3019760A1 (de) Gasentladungs-schaltroehre mit gekreuzten feldern
EP0810628A2 (fr) Source pour la génération de faisceaux d&#39;ions et d&#39;électrons pulsés à grande surface
DE102013015046B4 (de) Bildgebendes Massenspektrometer und Verfahren zum Steuern desselben
DE3688808T2 (de) Flüssigmetall-Ionenquelle.
EP2521427A1 (fr) Procédé et dispositif de formation d&#39;impulsions d&#39;ions à crêtes aplanies issus de sources d&#39;ions à faisceau d&#39;électrons
DE10335836B4 (de) Massenspektrometrieverfahren mit Ausbildung mehrerer axialer Einfangbereiche in einer Ionenfalle
DE202011050047U1 (de) Vorrichtung zur Formierung von Dachionenpulsen aus Elektronenstrahlionenquellen
DE102005021836A1 (de) Verfahren und Vorrichtung zum massenselektiven Ionentransport
DE102011104858A1 (de) Verfahren zur Erzeugung von hochenergetischen Elektronenstrahlen ultrakurzer Pulslänge, Breite, Divergenz und Emittanz in einem hybriden Laser-Plasma-Beschleuniger
EP1817788B1 (fr) Spectrometre de masse a temps de vol
DE102004055279B4 (de) Massenspektrometer
DE102022105233B4 (de) Vorrichtung und Verfahren zur Erzeugung kurzer Pulse geladener Teilchen
DE102010047331A1 (de) Ionenstrahlgerät und Verfahren zum Betreiben desselben

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

17P Request for examination filed

Effective date: 20130408

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20151201