[Sneap] Fe beam

[Dannie Steski]

We frequently produce a Fe beam from our MP for NASA. Because we are injecting a synchrotron we run in a pulsed beam mode so the source acts a little different than in the DC mode.

We found that using the black FeO powder produced higher intensities of FeO- than the red Fe2O3 powder. We also find that we have to replace the cathode every 3 or 4 days to deliver maximum intensities as slowly the output of FeO- from the cathode will drop. Presumably this is from depleting the Oxygen of the cathode. 

Dannie
*************************************************
Dannie Steski

Building 901A
Brookhaven National Laboratory
Upton, NY
11973

Tel: 631-344-4581
Fax: 631-344-4583
Steski at bnl.gov



  ----- Original Message ----- 
  From: David Weisser 
  To: Symposium of Northeastern Accelerator Personnel 
  Cc: Andrew Stuchbery ; Kitchen 
  Sent: Wednesday, June 11, 2008 9:42 PM
  Subject: Re: [Sneap] Fe beam


  The host for the 2008 SNEAP annual meeting is the University of Michigan at Ann Arbor.  The meeting dates are: October: 12 - 17, 2008.
  The meeting web link is: http://www-ners.engin.umich.edu/research/Mibl/Sneap/2008.htm




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  Stuart,

  We have been running Fe recently from a SNICSII.  Typical currents of 56Fe are 300 to 950 nA for a cathode currents of 600 micro-amps. The source can run with cathode currents of more than 1 mA.  We don't run enough Cu to compare Fe to though I expect Fe to be a factor of 5 lower than Cu.

  There have been mixed results with FeO.  Sometimes, for some cathodes, the FeO beam is a factor of 2 to4 times bigger than the Fe beam. For other samples, the Fe beam is bigger than the FeO.  It depends on how oxidized the material is.  We have run 57FeO from an isotopic sample getting 100 nA.  The isotopic material seems to be more oxidized than the natural material.

  There is some advantage in using the atomic rather than the molecular beam.  There is no Coulomb explosion in the terminal stripper foil and no dilution in the energy between the Oxygen and Iron getting to the terminal.  So the atomic beam can be at higher energy and higher charge state.

  It would be interesting to hear how you go.

  Regards,

  David
  ********************************************
  D.C. Weisser
  Nuclear Physics Department
  Research School of Physical Sciences and Engineering
  Australian National University
  Canberra A.C.T. 0200
  AUSTRALIA

  Tel:    + 61 (0)2 6125 2080
  Fax:    + 61 (0)2 6125 0748
  Mobile: + 61 (0)414 249 209

  david.weisser at anu.edu.au 

    -----Original Message-----
    From: sneap-bounces at tunl.duke.edu [mailto:sneap-bounces at tunl.duke.edu]On Behalf Of Van Deusen, Stuart B
    Sent: Thursday, 12 June 2008 8:03 AM
    To: sneap at tunl.duke.edu
    Subject: [Sneap] Fe beam


    Hello everyone

    We would like to produce an iron beam using a SNICS II source on our EN tandem.  We need to do implantation with a reasonable amount of current - we can get 300-400 nanoamp Cu beams pretty easily, and would like to get the same from an iron beam.  Advice on how to produce such a beam would be appreciated.

    Thanks in advance

    Best regards,
    Stuart Van Deusen

    -----------------------------------------------------------
    Stuart B. Van Deusen
    Radiation Solid Interactions and Processing
    Dept. 1111, M/S 1056
    Sandia National Laboratories
    P.O. Box 5800
    Albuquerque, NM  87185-1056
    PH (505)844-7782
    FAX (505)844-7775
    e-mail:  sbvande at sandia.gov




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