Lab Report for University of Notre Dame - Ed Stech Research Professor

Lab Report for
University of Notre
      Dame
          Ed Stech
      Research Professor
       estech@nd.edu

Outline

1.   Overview
2.   Operational summary
3.   New Additions/Changes
4.   Surplus Equipment
5.   Confusing FN Issue (Plea for help)

Nuclear Science Lab at Notre Dame

•   3 Pelletrons: 2 Tandems: 10 MV FN, 3 MV 9S, 1 Single Ended 5 MV 5U
•   18 Faculty (10 Tenure Track, 8 Research)
•   6 Staff (3 Accelerator, 1 Computer, 1 Electronics, 1 Admin)
     • Hope to post position for senior accelerator tech soon
•   3 Post Docs
•   34 Graduate Students
•   20 Undergraduate Students
•   Part of ISNAP, www.isnap.nd.edu
•   Research Funded primarily from NSF

5U Single Ended, 5MV

9S, 3MV Tandem

                                        FN, 10MV Tandem

FN       5U      9S
Operation hours of the accelerators   2018   1836.0   1977.0   178.9
                                      2019   2722.2    956.0   760.8
                                      2020   1206.9    750.1   451.5
                                      2021    485.5    466.2   247.5

New Addition to FN
With generous support from the Office of Research at ND, purchased a Dilo
system to convert from N2/CO2 to pure SF6 in FN.

New Additions to the lab
With generous support from the Office of Research at ND, purchased a Dilo
system to convert from N2/CO2 to pure SF6 in FN.

5U Beamline Addition
Wien Filter which is owned by Michael Paul from Hebrew University in Israel but
was loaned to Technical University Munich was transferred to ND for use with 5U.

5U Beam Contamination Prevents (a,g) Studies in
         Inverse Kinematics
20Ne5+ beam contaminated with
•   the obvious same M/Q ions (16O4+, 12C3+
    and 4He1+)
•   24Mg5+ at one 24Mg per ~1013 20Ne with

    the same p/q. That correspond exactly to
    the product of the 20Ne(α,γ)24Mg reaction           24Mg   expected
    with no possibility to differentiate.         19F
    We believe that charge state changes in the
    acceleration tube are the most probable
    culprit for the source.

The addition of a beamline Wien (velocity)
filter will cleanup the contamination.

In a first test however, the 24Mg contamination
was not visible but we were able to use the 19F
that is also present to show the way the WF                               20Ne
rejects contamination

Beamline Wien Filter Clears out beam
      Contaminants with same p/q
The measurement time was shorter
but it is clear that the 19F contamination
disappeared.
Future test with 16O4+ beam with mixture
of 20Ne in the ECR source will be performed
in the next few weeks                               24Mg   expected
                                              19F

                                                                      20Ne

Enge Split Pole from ORNL

Pole Gap 1.5”
Mean Radius 35.4”
Max Current 500A
Max Power 25 KW

Weight 66000 lbs.

Turns out leaving it outside, not great idea

New Home in East Target Room

Expansion into Far West Target Room

•   Adding a “new” SWM to allow for 2
    beamlines in after the first 2 super
    conducting solenoids of Twinsol.

•   One is another solenoid to expand
    on capabilities of the radioactive
    beams

•   Other is a newly funded Mass Trap
    funded by Brodeur’s MRI.

In Progress…

Other less obvious but critical
improvements
New water cooling system: Replaced old open drain system with new closed loop. Higher pressure
differential needed for some of the new equipment. Also had new electrical panels and feeds installed

New Power Supplies for FN Systems

“Free” Stuff to a good home

Originally acquired lots of stuff from ORNL when the
university was planning on getting a cyclotron. That fell
through so might be available.
Also, lots of old KN parts (Tubes, stabilizer, beamline
components).
Hope to get photos posted on website at some point.
Email me if you have specific needs or just want to stop
by and shop.

“Free Stuff”

FN Issue
 •   Happily running when suddenly corona current drops, then terminal voltage.
     You can keep the voltage for awhile but it takes significantly more chain
     current, eventually you max out and terminal voltage still drops.
 •   However, the charge doesn’t appear to go through any metered path to
     ground. Column to Terminal Voltage Ratio is correct.
 •   Bringing charge down to zero for a moment “fixes” it, you can then run bring
     things back up to nominal operations.
 •   Happens with and without stabilizer and beam. Also appears to be on both
     chains.
 •   Reducing corona current and/or points potential appears to make it better.
 •   Quick changes of charging balance (LE cup IN/OUT, switch between
     GVM/Slit, fast adjustments of Gains) is sometimes correlated with an event.
 •   Opened the tank last year, points slightly dull but nothing obvious.