25 research outputs found
High-chromaticity Optics for the MAX IV 3 GeV Storage Ring
The MAX IV facility is a 3rd generation state-of-the-art synchrotron light source currently under construction in Lund, Sweden. The MAX IV 3 GeV storage ring has a large negative natural chromaticity, which has to be corrected to positive values to prevent head-tail instabilities. On the other hand, high linear chromaticity can lead to a large tune footprint limiting Touschek lifetime. Therefore, the linear chromaticity is corrected to +1 in both planes with sextupoles while both sextupoles and octupoles are used to optimise the tune footprint. Studies indicate this design leads to threshold currents for resistive wall and transverse mode coupling instabilities beyond what is expected during regular user operation. However, since these are preliminary studies based on several approximations, the possibility of instability issues during commissioning needs to be considered. A short term solution is to operate the storage ring at a higher chromaticity. This thesis describes the development of a high-chromaticity optics for the MAX IV 3 GeV storage ring with linear chromaticity +4 in both planes. It focuses on reduction of chromatic and amplitude-dependent tune shifts to maximize dynamic aperture and Touschek lifetime. A comparison between the performance of the high-chromaticity optics and the design optics is also presented. The analysis reveals that the performance of the developed high-chromaticity optics is, not quite unexpectedly, poorer than the performance of the design optics. However, the performance of the high-chromaticity optics is estimated to be sufficient to allow the optics to be applied in the MAX IV 3 GeV storage ring as a short term solution if instability issues should occur during commissioning
UtvÀrdering och skötselanalys av rhododendrondalen i Göteborgs botaniska trÀdgÄrd
Den övre delen av rhododendrondalen i Göteborgs Botaniska TrÀdgÄrd Àr relativt nyanlagd, ombyggnaden startade i början av 1990-talet, med vÀxtmaterial frÄn insamlingsresor runt om i vÀrlden.
Rhododendronen har hÀr fÄtt en underordnad plats pÄ grund av de starkvÀxande perennerna som nu helt dominerar platsen under sommarmÄnaderna. DÀremot Àr nedre delen av rhododendrondalen inte förÀndra alls. Resultatet har nu blivit att den övre och nedre delen av rhododendrondalen skiljer sig, genom att den övre delen Àr mer genomarbetad. Den nedre delen har inte alls ett lika utvecklat gÄngsystem som den över delen har och det finns inte den mÀngden av olika perenner. I nedre delen Àr dessutom rhododendronen uppvuxna och klarar sig bra gentemot de fÄ perenner som finns. I detta omrÄde finns betydligt fÀrre arter rhododendron, men antalet plantor Àr stort. DÀrmed blir upplevelsen att nedre delen Àr mycket mer rhododendron dominerad, jÀmfört med den övre delen dÀr rhododendronen fÄr en underordnad betydelse vissa delar av Äret.
Om man i framtiden skall utöka rhododendrondalen med mer rhododendron och om man vill ha mer perenner sÄ gÀller det att man tar perenner som inte Àr aggressiva i sitt vÀxtsÀtt eller att man lÄter rhododendronen etablera sig först
Timing Modes for the MAX IV Storage Rings
The MAX IV facility includes two storage rings, operated at 1.5 and 3 GeV energy, for the purpose of producing high-brilliance synchrotron radiation for users. The 1.5 GeV ring replaces the previous MAX II and MAX III storage rings as a source of UV and soft X-rays, whereas the 3 GeV ring is optimized for hard X-rays. The 3 GeV ring is the first of a new generation of synchrotron light storagerings which employs multibend achromat lattices to achieve ultralow emittancesof a few hundred pm rad or below. Both rings were designed to operate with a uniform, multibunch fill pattern utilizing a 100 MHz RF system, resulting in a light repetition rate of 100 MHz. However, the MAX IV user community has initiated a discussion about timing modes at the rings and several research areas have been identified that require kHz - few MHz repetition rates. At many synchrotron light storage rings this is currently achieved by operating fill patterns with gaps of sufficient length for beamline choppers or gated detectors. This is not favorable for the MAX IV storage rings since they employ passive harmonic cavities to damp instabilities, increase Touschek lifetime, reduce heating of vacuum components and conserve the emittance at high bunch charge by lengthening the electron bunches. Studies at other storage rings have shown that fill patterns with gaps reduce the achievable bunch lengtheningand can drastically decrease the effectiveness of the harmonic cavities. This is of special concern for ultralow emittance rings since they have more demanding constraints to achieve stable beam, sufficient Touschek lifetime, acceptable heat load and low emittance at high bunch charge. This thesis presents research conducted to study possibilities of serving timing users that demand other light repetition rates than provided by the RF system at the MAX IV storage rings andother similar machines. Operation with fill patterns with gaps are studied as well as two methods, Pulse Picking by Resonant Excitation (PPRE) and Pseudo-Single-Bunch (PSB), that have the potential to serve timing and high-brilliance users simultaneously without requiring gaps in the fill pattern
First Measurements of Pulse Picking by Resonant Excitation (PPRE) at the MAX IV 3 GeV Storage Ring
At synchrotron light storage rings there is demand for serving high-brilliance users requesting multibunch operation while simultaneously serving timing users who require single-bunch operation. One method to accomplish this is PPRE developed and currently in user operation at BESSY II. In the method, the transverse emittance of one of the bunches in the bunch train is increased by an incoherent betatron excitation. Part of the light from this bunch can then be separated from the multibunch light by an aperture in the beamline, resulting in single-bunch light for the experiment. Methods such as this expand the scope of storage rings without requiring special fill patterns. This is of growing interest due to the upgrade trend towards diffraction-limited storage rings where it becomes more challenging to operate with inhomogeneous fill patterns. Measurements of PPRE were performed at the MAX IV 3 GeV storage ring utilizing the bunch-by-bunch feedback system both for excitation and as a diagnostic. Furthermore, measurements involving direct beam imaging at the diagnostics beamline allowed quantifying the effect of this excitation on the horizontal and vertical emittance
Patient benefit when using low-dose mothoxyflurane as pain relief in the ambulance care
Att möta patienter med smĂ€rta ingĂ„r i ambulanssjuksköterskans vardag. SmĂ€rta hos patienterna kan uppkomma av olika anledningar, i flera fall pĂ„ grund av trauma som resulterar i smĂ€rta för patienterna. Olika metoder för att lindra smĂ€rtan hos dessa patienter finns bĂ„de genom omvĂ„rdnad och medicinsk vĂ„rd. SmĂ€rtlindrande lĂ€kemedel finns i olika former med varierande effekt, latenstid samt biverkningar. Australien har sedan 70-talet anvĂ€nt sig av lĂ„gdos metoxifluran för att lindra smĂ€rta. LĂ€kemedlet introducerades nyligen i Sverige och skiljer sig frĂ„n andra smĂ€rtlindrande lĂ€kemedel genom att det inhaleras och dosen styrs av patienten sjĂ€lv. Syftet var att undersöka patientnyttan av behandling med lĂ„gdos metoxifluran hos patienter med akut mĂ„ttlig till svĂ„r smĂ€rta. Metoden som har anvĂ€nds Ă€r en litteraturöversikt med systematisk ansats dĂ€r fjorton artiklar ligger till grund för att undersöka patientnyttan med lĂ„gdos metoxifluran. Sökningarna efter vetenskapliga artiklar har gjorts i databaserna PubMed samt CINAHL. Samtliga artiklar har granskats med hjĂ€lp av en kvalitetsgranskningsmall rekommenderad av Sophiahemmets Högskola. De 14 vetenskapliga artiklarna analyserades genom en integrerad analys och resulterade i tre teman och sju underteman. Resultatet visar pĂ„ flertalet positiva effekter i anvĂ€ndandet av lĂ„gdos metoxifluran. DĂ€ribland tiden till administrering och smĂ€rtlindring, god smĂ€rtlindrande effekt samt metoxiflurans minimala pĂ„verkan pĂ„ vitalparametrar. Vissa negativa effekter framkom ocksĂ„ i resultatet dĂ€r mĂ„nga biverkningar kunde ses, samt varierande smĂ€rtlindrande effekt beroende pĂ„ Ă„lder. Slutsatsen Ă€r att lĂ„gdos metoxifluran Ă€r ett lĂ€kemedel med positiva effekter för patienter med smĂ€rta samt ett gott komplement till traditionella smĂ€rtlindrande lĂ€kemedel i Sverige. Genom kombinationen av god personcentrerad medicinering och personcentrerad omvĂ„rdnad kan ambulanssjuksköterskan individanpassa vĂ„rden i komplexa miljöer.Meeting patients in pain is part of the ambulance nurse's everyday life. Pain in the patients can arise for various reasons, but in several cases due to trauma that results in pain for the patients. Different methods to relieve the pain in these patients are available both through nursing and medical care. Pain-relieving drugs are available in different forms with varying effects, latency, and side effects. Australia has used low dose methoxyflurane to relieve pain since the 1970âs. The drug was recently introduced in Sweden and differs from other painrelieving drugs in that it is inhaled, and the dose is controlled by the patient himself. The aim of was to investigate the patient benefit of treatment with low dose methoxyflurane in patients with acute moderate to severe pain. The method that has been used is a literature review with a systematic approach where fourteen articles form the basis for investigating the patient benefits of low dose methoxyflurane. The searches for scientific articles have been made in the databases PubMed and CINAHL. All articles have been reviewed using a quality review template recommended by Sophiahemmet University. The 14 scientific articles were analyzed through an integrated analysis and resulted in three themes and seven under themes. The results show most positive effects in the use of low dose methoxyflurane. Including rapid administration and pain relief, good pain relief effect and methoxyflurane's minimal impact on vital parameters. Some negative effects also appeared in the results, where many side effects could be seen as well as varying pain-relieving effects depending on age. The conclusion is that low dose methoxyflurane is a drug with positive effects for patients with pain and a good complement to traditional pain-relieving drugs in Sweden. Through the combination of good person-centred medication and person-centred care, the ambulance nurse can individually adapt care in complex environments
High-Chromaticity Optics for the MAX IV 3 GeV Storage Ring
The ultralow emittance lattice of the MAX IV 3 GeV storage ring has a large negative natural chromaticity. This has to be corrected to positive values to prevent head-tail instabilities. On the other hand, high linear chromaticity can lead to a large tune footprint which limits Touschek lifetime. Therefore, the linear chromaticity is corrected to +1.0 in both planes with sextupoles while octupoles are used to further reduce the tune footprint. Studies indicate this design leads to threshold currents for resistive wall and transverse mode coupling instabilities beyond what is expected during regular user operation. However, since these are only preliminary studies based on approximations, the possibility of instability issues during commissioning needs to be considered. An inexpensive, short term solution is to operate the storage ring at a higher chromaticity. This paper describes the development of a high-chromaticity optics for the MAX IV 3 GeV storage ring. It focuses on reduction of chromatic and amplitude-dependent tune shifts to maximize dynamic aperture and Touschek lifetime. A comparison between the performance of the new high-chromaticity optics and the design optics is also presented
Jag lever som jag vill, eller jag lever som jag lÀr? En enkÀtstudie med avseende att undersöka 15 Äringars BMI, kost-motionsvanor samt socialisationens pÄverkan av dessa
The habits of living are seen as important factors for public health, and are related to the primary socialization. Exercise and food habits are two main factors for development of health or ill health and are both related to the overweight epidemic. The overweight increase among children and youth has been given particular attention. The aim of this study is to examine how 15 year olds Body Mass Index, food- and exercise habits are connected to each other and also how they are related to socialization. The study is a cross sectional survey among 208 pupils in ninth grade, Kristianstad. 168 pupils were responding the questionnaire. The result showed less prevalence of overweight and higher prevalence of underweight than were expected. There emerged no connection between Body Mass Index and the pupilâs habits of living. On the other hand we found a strong connection between the primary socialization and habits of living. The study also shows a link between the different habits of living. We propose that public health work directed to childrenâs and youths in many ways should be focused on the primary socialization. We also want to attract more attention to the underweight among youths because of the indications that the prevalence is higher than expected
Patient benefit when using low-dose mothoxyflurane as pain relief in the ambulance care
Att möta patienter med smĂ€rta ingĂ„r i ambulanssjuksköterskans vardag. SmĂ€rta hos patienterna kan uppkomma av olika anledningar, i flera fall pĂ„ grund av trauma som resulterar i smĂ€rta för patienterna. Olika metoder för att lindra smĂ€rtan hos dessa patienter finns bĂ„de genom omvĂ„rdnad och medicinsk vĂ„rd. SmĂ€rtlindrande lĂ€kemedel finns i olika former med varierande effekt, latenstid samt biverkningar. Australien har sedan 70-talet anvĂ€nt sig av lĂ„gdos metoxifluran för att lindra smĂ€rta. LĂ€kemedlet introducerades nyligen i Sverige och skiljer sig frĂ„n andra smĂ€rtlindrande lĂ€kemedel genom att det inhaleras och dosen styrs av patienten sjĂ€lv. Syftet var att undersöka patientnyttan av behandling med lĂ„gdos metoxifluran hos patienter med akut mĂ„ttlig till svĂ„r smĂ€rta. Metoden som har anvĂ€nds Ă€r en litteraturöversikt med systematisk ansats dĂ€r fjorton artiklar ligger till grund för att undersöka patientnyttan med lĂ„gdos metoxifluran. Sökningarna efter vetenskapliga artiklar har gjorts i databaserna PubMed samt CINAHL. Samtliga artiklar har granskats med hjĂ€lp av en kvalitetsgranskningsmall rekommenderad av Sophiahemmets Högskola. De 14 vetenskapliga artiklarna analyserades genom en integrerad analys och resulterade i tre teman och sju underteman. Resultatet visar pĂ„ flertalet positiva effekter i anvĂ€ndandet av lĂ„gdos metoxifluran. DĂ€ribland tiden till administrering och smĂ€rtlindring, god smĂ€rtlindrande effekt samt metoxiflurans minimala pĂ„verkan pĂ„ vitalparametrar. Vissa negativa effekter framkom ocksĂ„ i resultatet dĂ€r mĂ„nga biverkningar kunde ses, samt varierande smĂ€rtlindrande effekt beroende pĂ„ Ă„lder. Slutsatsen Ă€r att lĂ„gdos metoxifluran Ă€r ett lĂ€kemedel med positiva effekter för patienter med smĂ€rta samt ett gott komplement till traditionella smĂ€rtlindrande lĂ€kemedel i Sverige. Genom kombinationen av god personcentrerad medicinering och personcentrerad omvĂ„rdnad kan ambulanssjuksköterskan individanpassa vĂ„rden i komplexa miljöer.Meeting patients in pain is part of the ambulance nurse's everyday life. Pain in the patients can arise for various reasons, but in several cases due to trauma that results in pain for the patients. Different methods to relieve the pain in these patients are available both through nursing and medical care. Pain-relieving drugs are available in different forms with varying effects, latency, and side effects. Australia has used low dose methoxyflurane to relieve pain since the 1970âs. The drug was recently introduced in Sweden and differs from other painrelieving drugs in that it is inhaled, and the dose is controlled by the patient himself. The aim of was to investigate the patient benefit of treatment with low dose methoxyflurane in patients with acute moderate to severe pain. The method that has been used is a literature review with a systematic approach where fourteen articles form the basis for investigating the patient benefits of low dose methoxyflurane. The searches for scientific articles have been made in the databases PubMed and CINAHL. All articles have been reviewed using a quality review template recommended by Sophiahemmet University. The 14 scientific articles were analyzed through an integrated analysis and resulted in three themes and seven under themes. The results show most positive effects in the use of low dose methoxyflurane. Including rapid administration and pain relief, good pain relief effect and methoxyflurane's minimal impact on vital parameters. Some negative effects also appeared in the results, where many side effects could be seen as well as varying pain-relieving effects depending on age. The conclusion is that low dose methoxyflurane is a drug with positive effects for patients with pain and a good complement to traditional pain-relieving drugs in Sweden. Through the combination of good person-centred medication and person-centred care, the ambulance nurse can individually adapt care in complex environments
High-chromaticity Optics for the MAX IV 1.5 GeV Storage Ring
The MAX IV facility currently under construction in Lund, Sweden will include a 1.5 GeV storage ring. To prevent head-tail instability, the negative natural chromaticities of the MAX IV 1.5 GeV storage ring have been corrected to positive values using sextupole gradients in the focusing quadrupoles along with dedicated sextupole magnets. To allow adjustment of the chromaticity correction, weak correction sextupoles have been inserted into the lattice. A high-chromaticity optics has been developed for the MAX IV 1.5 GeV storage ring in case instability issues arise during commissioning. Two chromatic sextupole families were used to correct the linear chromaticity. The tune footprint was then tailored using the remaining two sextupole families with the goal of maximizing dynamic aperture and Touschek lifetime. This paper describes the recently developed high-chromaticity optics for the MAX IV 1.5 GeV storage ring and discusses performance limitations of the optics constrained by available gradient strength in the sextupoles
Pulse-Picking by Resonant Excitation (PPRE) for Timing Users at the MAX IV 3 GeV Storage Ring
At synchrotron light storage rings there is demand for serving both high-brilliance and timing users simultaneously. At many rings this is commonly achieved by operating fill patterns with gaps of sufficient length, but this is not favorable for rings that operate with passive harmonic cavities to damp instabilities and increase Touschek lifetime by lengthening the bunches. For such rings, gaps in the fill pattern could severely reduce the achievable bunch lengths. For the MAX IV 3 GeV storage ring, sufficient bunch lengthening is also essential for conserving the ultralow emittance and reducing heat load on vacuum components at high current. It is therefore of interest to study methods to serve timing users while operating without gap in the fill pattern. Once such method is PPRE, where the transverse emittance of one bunch in the bunch train is increased by an incoherent betatron excitation. This paper presents simulations for the MAX IV 3 GeV storage ring and discusses the machine requirements as well as the achievable performance for timing users