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  • \(^{32}\)Si(\(d\),\(p\)) Prep

    Energy loss calculations of beam for recoil Si detectors. First what is needed is the minimum beam energy, then reduce by production target energy loss.


    Experiment has been scheduled for September 22\(^{nd}\) - 28\(^{th}\). There is the possibility of pre beam production on September 1\(^{st}\) or September 15\(^{15}\).

    Primary beam of \(^{34}\)S\(^{8+}\) at 374 MeV (11 MeV/u) to produce \(^{32}\)Si\(^{14+}\) (86.5%) at 10.1(3) MeV/u through a 5 mg/cm\(^2\) Be production target. Degraded \(^{34}\)S through production is 9.7(2) MeV/u.

    Primary Beam

    374 MeV \(^{34}\)S\(^{8+}\) through 5 mg/cm\(^2\) Be production target leaves 9.7(2) MeV/u \(^{34}\)S with the charge state distribution below.

    374 MeV \(^{34}\)S through 5 mg/cm\(^2\) Be production target.
    Charge State Fraction (%)
    16 73.5
    15 25.5
    14 1
    13 0.01
    12 6e-5

    Note from Bob Scott on the \(^{34}\)S charge state: From: Scott, Robert H. The peak c.s. for \(^{34}\)S is 8+, you get about 1/3 peak output for 10+, 11+ output is reduced from 10+ to 1/3.

    My reply to Matt Hendricks on minimum energy: Acceptable Low-Energy for 34S: 374 MeV (11 MeV/u). Acceptable beam current limit: >250 particle nano-Amps (> 2 euA for 34S8+ I believe).

    Response from Richard Pardo: The 2.2 euA of 34S8+ would be 275 pnA. With 60% transmission that would be. 165pnA. Doubling that assuming some source improvement and higher enrichment then gets us to the  325 pnA regime at the gas cell. So we definitely don’t want to strip this to get higher energy. I hope our “G” cryo repairs work and we have a reliable resonator operation for that cryostat by August.

    Bob Scott purchased enriched material: 99.5% 34S for $4.8/mg. I have a quote for 400mg at a total of $1944.00 USD.

    Secondary Beam

    Working in /Research/anl/helios/h0XX/beam_dev with LISE++ output in ray_files. Will generate full outputs for various targets starting with the 374 MeV \(^{34}\)S beam, convert to ROOT files and compare energies and identification plots. Outputs from LISE++ will include those in the figure below.

    User cross section is of the s34dp_10.txt type for all recoils. s36_cd2.txt for the \(^{34}\)S beam.

    Production using a 5 mg/cm\(^2\) Be target.

    Charge state distribution for 374 MeV \(^{34}\)S to \(^{32}\)Si through 5 mg/cm\(^2\) Be target.
    Charge State Percent (%)
    14 86.5
    13 13.3
    12 0.2
    Lab angle vs. energy relationship for \(^{32}\)Si from 374 MeV \(^{34}\)S beam on 5 mg/cm\(^2\) target.
    Lab Angle Energy (MeV/u)
    2 10.3
    4 10.1
    6 9.9

    Output file from LISE++.