Radioactive Projectile Excitation Experiments
The Transient Field technique was successfully used to measure
magnetic moment of radioactive 76Kr at Berkeley.
A proposal RIB-112: Measurement of the 2+ state of 132Te produced as radioactive beam
was approved and a test experiment was performed in July 2004. A summary
of the experiment is provided here .
With the lessons learned, a new chamber was installed and the experiment
rescheduled for spring 2007. The radioactive beam could not be delivered
as scheduled and instead the new setup was tested with stable 130Te.
The results of this test are summarized.
The findings are:
- With the larger opening angle Φ = 21 - 47° of the particle detector
and the higher exit velocity of the probe ions from the target,
the measured slope is 1.6, attenuated from an expected 2.4.
- A thick C (min 1 mg/cm2) target is needed to achieve
a meaningful statistic in the allotted time.
- The total thickness of the target should not exceed
6 mg/cm to limit the spread of the radioactive beam in
Experiment from June 22. to July 3. 2007
Two different targets were used;
1.3 mg/cm2 C on 4.9 mg/cm2 Gd
backed by 0.8 mg/cm2 of Cu (added solely to improve thermal conductivity)
1 mg/cm2 C on 4.4 mg/cm2 Fe.
Both targets were cooled to 77 K with liquid nitrogen.
The coincidence rate was at best 1 every 18 seconds per
Clover detector for a total of about 700 counts per Clover and field
The data are still being analyzed but the preliminary result g(2+) = +0.3(0.17) is in agreement with Ref. . An important part of this experiment was the
determination of the sign of the g factor, which is as expected positive.
The success of this experiment provides a proof of principle and is a guide
for future measurements. A report can be found in the HRIBF News Letter. The experiment was also reported at the DNP meeting of the APS in October 2007 in Newport News, VA (BAPS Vol. 52, No. 9 October 2007, DA47, HG7).
The final publication can be found in Phys. Lett. B664, 241-245 (2008)
N. J. Stone,
A. E. Stuchbery,
C. R. Bingham,
C. J. Gross,
D. C. Radford,
J. R. Stone and
N. V. Zamfir, Phys. Rev. Lett.
Last modified: Thu Jan 21 21:21:07 EST 2010