The MAX-lab facility Glasgow September 2008 BS 1.

The MAX-lab facility

Glasgow September 2008 BS

1


2

MAX IMAX III

MAX II

FEL

Injector

Nuclear Physics area

MAX I storage ring (550 MeV)/stretcher 1986MAX II storage ring (1.5 GeV) 1995MAX III storage ring (.7 GeV) 2007FEL (test facility) 2007MAX IV proposal 2007 (VR governement)

40 weeks per year SR at MAX II, MAX III22 weeks per year SR at MAX I18 weeks per year nuclear physics at MAX I(4 x 4 weeks + 1 x 2 weeks)

The MAX-lab facility

Glasgow September 2008 BS 3

MAX-lab

Staff: 80PhD students located at MAX-lab: 13

MAX-lab is a national facility funded by the Swedish Research Council (VR 50 MSEK) and Lund University (20 MSEK). Two Divisions belonging to the Natural Science Faculty: Accelerator Physics and Instrumentation for Synchrotron Radiation Research, are placed at MAX-lab.

MAX-lab is foremost a synchrotron radiation facility.


linac

linac

gun

gun

chicane

250 MeV

500 MeV

Injector overview

recirculator

Two linacs with a recirculator for injection into MAX II and MAX III.Nominal: 125 MeV per linacActual: 100 MeV per linacSpace limitations prevent recirculation for injection into MAX I

To MAX I


For nuclear physics, the linacs operate at 10 Hz giving an electron pulse some 100-200 ns wide. The electron beam is injected into the stretcher ring MAX I. The electron beam is extracted slowly during the 100 ms interval between pulses from the injector. The stored electrons are ”shaked” and move towards the thin extraction septum.The average beam current in the ring is about 20 mA, resulting in an extracted current of 20 nA (106 ).

Cavity to compensate synchrotron light losses in the dipole magnets

Lars-Johan Lindgren


The synchrotron light from a bending magnet observed with a CCD camera. The division is 20 ms. The electrons in the ring are almost entirely extracted between injections.

The extracted beam seen by a nuclear detector in the experimental area. Shown is a TDC spectrum started by the linac trigger and stopped by an event in the detector (in this case a NaI(Tl)). The spectrum was obtained during a tagging efficiency measurement with the NaI detector as trigger. Part of the events are accidentals from cosmic radiation.


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Experimental areaShielding indicated by

BUNIDIANA

CATS


Ee

30o dipole50o magnet

Beam dump FC

ET

MT Photon beam

E

Dump magnet

Focal plane hodoscope E’

radiator

radiator

E = Ee – E’

SAL tagging spectrometers

MT: Main taggerET: EndPoint taggerFC: Faraday cup

Scale: 6 m between pillars


MT

setting 340 setting 460

Main Tagger

Setting 460

Setting 340

The MT settings are determined by the magnetic field in the tagging magnet

ET


31 MeV 95 MeV Ee = 188,5 (MeV)

MT setting 340

SAL focal plane hodoscope

E= (95-31)/62≈ 1 MeV

The focal plane hodoscope consists of 63 scintillators with 50 % overlap resulting in 62 channels.

The collimator arrangement for the November - December 2006 deuterium run.

MT vacuum

400

The collimator assembly consists of a heavymet main collimator, 108.5 mm long, with an entrance opening of 12 mm and an exit opening of 13 mm. The outer diameter of the main collimator is 80 mm. With the collimator inset used, the opening angle is 3,3 mr. The beam spot size at the target position is then expected to have a diameter of 37 mm. This agrees well with photos taken during the deuterium run.

Collimator assembly

cell center

distance to ET radiator: 3 585,3 mmdistance to MT radiator: 1 689,5 mm

144

Target

3299,5

125 45

Lead brick

2485



Tagger setting Ee (MeV) E (MeV) E (MeV)

MT 460 146,3 57,5 – 92,0 0,56

154,1 57,0 – 95,5 0,59

163,0 64,1 – 102,8 0,62

171,7 67,52 – 108,2 0,66

179,2 70,0 – 112,91 0,69

188,5 74,1 – 118,8 0,72

MT 340 146,3 26,2 – 73,1 0,76

ET 146,3 100 – 116 0,5

188,5 162 – 175 0,42

194 167 - 180 0,41

Energy ranges

Dmytro Pugachov


The location of the focal plane for three different positions of the radiator at the MT.

Old target 6.55 cm refers to the SAL radiator wheel in the normal position slightly inside the magnetic field.

Old target -18.55 cm refers to the SAL radiator wheel in a position outside teh magnetic field after a 180o rotation of the wheel.

Crystal -26.5 cm refers to the position of the center of the goniometer.

Coherent bremsstrahlung

New radiator chamber

Goniometer

The goniometer may be removed and replaced by the SAL radiator wheel within a few hours.

The electronbeam


The goniometer at MAX-lab


Two 2 week periods have been used for commissioning of the coherent beam with the participation of the Kharkov group and Ken Livingstone from Glasgow.

Vladimir Ganenko will report on these tests.

The project was supported by the I3HP JRA3 EuroTag funding a postdoc, Dmytro Pugachov, for two years. The equipment was funded by the Swedish Research Council and the Royal Physiographic Society in Lund.


Magnus Lundin, Thesis; http://www.maxlab.lu.se/kfoto/Publications/Thesis/lundin.pdf


TOF spectrum from Carbon with an energy cut selecting elastically scattered photons.

The structure separated by 305 ns is caused by the shaker (3.3 MHz). The structure separated by 108 ns is caused by uneven filling of the ring (circumference 32 m).


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Luke Myers

Tagging efficiency


Proposed experiments in December 2004

Proposal No. 1 Photodisintegration of Li-isotopesProposal No. 2 the total photoabsorption cross section of 6,7Li below p-threshold

Proposal No. 3 Compton scattering from 4He and 12C

Proposal No. 4 PARTIAL REACTIONS OF PION PHOTOPRODUCTION AT LIGHT NUCLEIProposal No. 5 Measurement of Photoreactions on Helium Isotopes using Gas-Scintillator Active TargetsProposal No. 6 Elastic Compton Scattering from Deuterium at 40-110 MeVProposal No. 7 Threshold Neutral Pion Photoproduction in Hydrogen and DeuteriumProposal No. 8 Photofission of Heavy Actinide Nuclei at MAX-LabProposal No. 9 Low-pressure MWPC Technique in Nuclear Experiments with Electron and Photon ProbeProposal No. 10 INITIAL COMMISSIONING OF THE Ge6 ARRAY AT MAXLABProposal No. 11 Study of the Halo Nucleus 6He using the 6Li(,p+)6HeReaction

Proposal No. 12 Deeply Bound Pionic Atoms from the (,p)ReactionProposal No. 13 High-resolution Measurement of the 4He(,pn)Reaction

Proposal No. 14 Charged Pion Photoproduction from Threshold up to the First-Resonance Region

+ a few more in 2006.

http://www.maxlab.lu.se/kfoto/ExperimentalProgram/PAC/2004/proposal04-nr1.pdf


























































Runperiod 1 2005.05.09 - 2005.06.06 Runperiod 2 2005.09.19 - 2005.10.03 Runperiod 3 2005.10.17 - 2005.10.31 Runperiod 4 2005.12.05 - 2005.12.19 Runperiod 5 2006.02.13 - 2006.03.13 Runperiod 6 2006.04.24 - 2006.05.22 Runperiod 7 2006.10.16 - 2006.11.06 Runperiod 8 2006.11.27 - 2006.12.18 Runperiod 9 2007.02.12 - 2007.03.12

Runperiod 10 2007.04.16 - 2007.04.30 Runperiod 11 2007.05.28 - 2007.06.25 Runperiod 12 2007.09.10 - 2007.10.08 Runperiod 13 2007.11.05 - 2007.12.03 Runperiod 14 2008.02.18 - 2008.03.17

Editor: Kevin Fisum

Run Reports

http://www.maxlab.lu.se/kfoto/ExperimentalProgram/runperiods/period1.html






http://www.maxlab.lu.se/kfoto/ExperimentalProgram/runperiods/p4/period4.html




http://www.maxlab.lu.se/kfoto/ExperimentalProgram/runperiods/runperiod06.pdf








New focal plane hodoscope

An application to the Knut and Alice Wallenberg Foundation was submitted in December 2007 and funded in June 2008.

The design is very similar to the Glasgow design for the tagger in Mainz. We will use the same electronic boards designed by John Annand and the same Hamamatsu 10 mm diameter PM tubes. The application also covers new data aquisition equipment.

The length of the focal plane for the MT is 1240 mm, and for the ET 1330 mm. We will build a 1200 mm long hodoscope with 160 scintillators, each 3 x 10,5 x 60 mm.


Electron energy (MeV)

Photon energy range (MeV)

Photon energy resolution (MeV)

Tagging system

100 39 – 70 0.21 MT (460)

100 17.6 – 41.2 0.29 MT (340)

150 58.7 – 104.3 0.32 MT (460)

190 74.3 – 132.2 0.41 MT (460)

210 155 – 190 0.25 ET

250 195 – 230 0.25 ET


MT

ET

15 mm diameter


MainzThe Lund design (the cards are not shown) limited by the requirement that the scintillator array must be rotated.


Overview of the Lund focal plane hodoscope with the actual dimensions of the electronic cards seen in the photo.


Design goals: electron energy 100 – 250 MeV intensity 40 nA

N~ 1 MHz/MeV75 % duty cycle

Today: electron energy 144 – 200 MeVintensity 30 nAN~ 0.5 MHz/MeV 75 % duty cycle

Remaining issues: maximum electron energytime structure in the beam

Seattle June 2008 BS 29

The local nuclear physics group (Jason Brudvik, Kevin Fisum, Kurt Hansen, Lennart Isaksson, Magnus Lundin and BS) acknowledge the support by the European Community - Research Infrastructure Action under the FP6 "Structuring the European Research Area" Programme (through the Integrated Infrastructure Initiative "HadronPhysics"), and furthermore the support by the Swedish Research Council, the Craaford Foundation, the Wennergren Foundation, the Royal Physiographic Society in Lund and the Knut and Alice Wallenberg Foundation.


Beam monitors

In-beam monitor, John Annand

PILATUS, Roger Rassool, Vivien Lee, Roger Peake

CCD camera, Kurt Hansen, Jenny Ber, Claire Van Ngoc Ty


John Annand

This in-beam monitor is used for experiments upstream of the target. The ratio between the count rate of the in-beam monitor and the count rate in the focal plane is proportional to the tagging efficiency and may be used to monitor this quantity during a run.


The pixel apparatus for the SLS is a novel type of X-ray detector developed at the Swiss Light Source. It is a two-dimensional hybrid pixel array detector operating in a single-photon counting mode. The module used at MAX-lab is composed of approximately 100 000 172 m square pixels arranged in a matrix 487 x 192. It comprises a preamplifier, a comparator and a counter. The readout time is 5 ms. The count rate may be as high as 1,5 MHz/s/pixel. The detector is mainly sensitive to X-rays with energies below 20-50 keV.


The socalled time in pulse spectrum. A TDC is started by the machine trigger and stopped by a recoil electron in the focal plane hodoscope.


Poor (wo)man’s version of PILATUS

CURIX ORTHO FINEGadolinium

A Win TV Express from Hauppauge produces 25 frames per second at a resolution 384 x 288 pixels on the computer screen. Frames may be grapped and saved as a jpeg file. The TV card is controlled with a C/C++ program using root for the processing and for the graphics.

http://www.maxlab.lu.se/kfoto/Publications/Master/berg.pdf

ASTOVID StellaCam IITM


Threshold set at 0 Threshold set at 100


Threshold set at 90

The beam is moved in the vertical direction

The MAX-lab facility Glasgow September 2008 BS 1.

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