Mass determination of 20,22^{20,22}Ne, 36,40^{36,40}Ar, and 86^{86}Kr for tests of the performance of a Penning trap when using highly charged ions

Atomic mass values are used in various fields of physics as indispensable parameters often requiring a very high accuracy. Until recently the mass measurements were performed in classical mass spectrometers reaching in the best cases a mass uncertainty of about 10 ppb. Penning traps are now able to determine atomic masses at an accuracy several orders of magnitude better. The Penning trap mass spectrometer SMILETRAP at the Manne Siegbahn Laboratory has been used to determine the masses of a number of isotopes with mass numbers in the region 1-204 and charges from 1+ to 52+. making use of the fact that the precision increases linearly with the charge state of the ion. In this paper we present mass measurements on **2**0**, **2**2Ne, **3**6**, **4**0Ar, and **8**6Kr at an uncertainty about 1 ppb. The masses of the five isotopes are 19.992 440 175 9(20) u, 21.991 385 115(19) u, 35.967 545 105(29) u, 39.962 383 123 2(30) u and 85.910 610 730(110) u respectively. These mass determinstions have been used to determine several properties of the SMILETRAP mass spectrometer. 50 Refs

A new determination of the

The atomic and nuclear masses of 4He and 3He have been measured using doubly charged ions in a Penning trap connected to an electron beam ion source. Recent technical improvements allow mass determinations with uncertainties of a few parts in 1010. The obtained atomic masses are 4.002 603 256 8(13) u and 3.016 029 323 5(28) u respectively. These values deviate by as much as 5 standard deviations from the accepted values

SMILETRAP—A Penning trap facility for precision mass measurements using highly charged ions

Inequality between Maori and non-Maori has been an enduring feature of New Zealand society. But in recent decades, it has coincided with another unwelcome development: the growth of income gaps within Maori communities. These inequalities stem from the general social and economic position of Maori in New Zealand society, but also from the policies pursued by both Labour and National governments from 1984-99 and largely retained, although modified and softened, by Labour-led governments from 1999- 2008. Despite the overwhelming evidence that these policies substantially increased inequality, as detailed in this chapter, they have been revived and extended by National-led governments since 2008. This raises controversial questions about the current direction of Maori economic and social development. Who is currently benefiting, and who is not? To what extent do current ideas about Maori development empower some groups of Maori, while disenfranchising or marginalising others

Lessons learned from a HDR brachytherapy well ionisation chamber calibration error

The outcomes of a recent brachytherapy welltype ionization chamber calibration error are given in the hope that other brachytherapy treatment centres may better understand the importance of each entry stated in a well chamber calibration certificate. A Nucletron Source Dosimetry System (SDS) PTW well-type ionization chamber was sent for a biennial calibration in September 2010. Upon calibration of the chamber, it was discovered that the previous calibration (in July 2008) contained a +2.6% error in the chamber calibration coefficient. Investigation of the information on the 2008 well chamber calibration certificate indicated the source of the error, which could or should have been detected by both the calibration laboratory and/or the radiation therapy department upon return of the chamber. Consideration must be given to all values and conditions given on the calibration certificate when accepting a ionization chamber back from a calibration laboratory. The issue of whether the source strength from the source calibration certificate or the measured source strength from the calibrated ionization chamber should be entered into the treatment unit is also raised