Luminosity Spectrometer Project Status

Date Comments
April-May 2002  Offline analysis is code being setup and put to /nevis/nevis11/CVS. Type (>cvs co specanal) to get the get code.  
April 2002 The first data with pedestals and charge test were taken. The pedestals are found to be quite unstable due to low frequency noise in the Front-End. 
March-April 2002 The data taken in the fall with a temporary CAMAC type DAQ were analyzed and are in a general agreement with the fast simulation.
Feb-April 2002   The helium bag rebuilt to start after the colimator.
Jan 2002 The gas system for the Helium bag doesn't work. The flow of He is too low. The tests with nitrogen showed, that the connection from the hall to the tunnel works fine. The other tests will be done soon. The valves of the He bag has to be replaced. The original ceramic based valves got damaged (probably by radiation). 
Jan 2002 The PRL's - the radiation monitors were placed in the spectrometer area to monitor the radiation levels comming from the synchrotron radiation.
Jan 2002 We are able to control the High Voltage from luxury machine with the new QT based cprogram.
 Jan 2002 7 cables to FEE were found to be broken and replaced. (work mre carefully in the rack area).
All the channels transmit signals to the hall.
 Jan 2002  The LED pulser from the new electronics is working and the pulses 
Jan 2002 Two students to be working with spectrometer arrived. Yuanbo Zhang and Yujin Ning.
Jan.2002 Helium bag is installed. The design has problems and the fixed collimator cannot be closed. We get ready for testing the gas connection.
10.Jan.2002 Problems with High Voltage solved. The current loop RS232 was installed and a faulty box was indentified causing communication problems in all the chain.
Dec.2001 Survey of the spectrometer position finished. See  results .
Nov. 2001 Test of electronics using charge injection going on. Some channels are still noisy - probably due to wrong timing of memory boards.
19-21.Nov 2001 The Front-end electronics, memory boards, integrators and Flash ADCs have been installed. Spectrometer is cabled up to the Front-end electronics.
19-21.Nov 2001 Spectrometer surveyed and confirmed to be 6mm low. The beam is however on right place. The collimators have been adjusted due to this problem. Fixed collimator by -4mm the moving collimator by -6mm.
19-21.Nov 2001 Support for the shielding is put on.
Nov 2001  Few thousands of events taken. Everything looks fine except of the overall energy calibration which is inconsistent with the Bdl value at 17% level. This might be an effect of the long cable form hall to the tunnel.
Oct 2001  First cca 80 events observed in a long run. First spectra and correlations look reasonable.
Oct 2001  First hits observed!
This includes single hits and proton beam induced events.  No coincidence so far.
Oct 2001 The dipole magnet was turned on to 200A with no effect on the proton beam operation.
Sep 2001  All channels working!
Sep 2001 Last 3 problematic channels repaired.  Two new "dead" channels appeared, we suspect problems with connection from the tunnel to the hall. 1 hour access is needed in order to check this.
Sep 2001 LED monitoring system running. Correlation with beam operation observed.
Sep 2001  Table for the moving collimator connected to slow control and tested.
Sep 2001   Surveying the detector showed 8mm offset from the designed position. This was due to wrong installation of the beam pipe. Beam pipe will be moved during the next long access (october?).
Sep 2001 New High Voltage cables built and successfully installed in the tunnel. This replacement solved problems with broken old HV cables and they are longer which allows us to have much nicer installation and no pressure is applied on the bases.
Aug 2001 HV system repaired by NIKHEF. 
Aug 2001 Problems with one HV box identified. The box was working before - is the fuse out? 
One communication box (working before) is not responding. Two other comboxes tested. 
Aug 2001 System surveyed for position
Aug.2001 Moving Collimator Installed
July 2001 LED monitoring system for LSD Up running
July  2001 LSD Down tested. Few channels cannot hold HV's.
July 2001 10 spare HV cables installed in the tunnel. Broken cables for LSD Up changed and tested. All channels can hold HV's but some are still not responding.
June 2001 LSD Up successfully powered up. Some channels cannot hold the HV's some channels not responding.
June 2001 Table for moving collimator installed in the tunnel.
June 2001 LED's installed in the tunnel.
June 2001 4 summer students arrived: Keewee Tan, Yuanbo Zhang, Monica Skoge and Ann Smith
May 2001 Fixed beam collimator installed
10.May 2001 Fixed beam collimator ready.
10.May 2001  Cables put under the floor in the tunnel.
2.May 01 Proton beam pipe shielding on place.
30.April 01 Both detectors are placed into the tunnel.
25.April 01 LSD support structure on place in the tunnel.
24.April 01 LSD support structure ready
4.April 01 Led distribution system tested and proven to work.
2.April 01 Exit window installed and surveyed. Proton beam line is installed. 
March 01 LSD support structure design ready. Construction started.
March 01 Beam collimator design ready and put to production.
19.March 01 Magnet installed in the tunnel. 
15.March 01 The thickness of the exit window measured with high precision. See the  results .
Feb 01 Magnet including proton beam pipe shielding tested!
Magnetic field and BdL measured at different currents and positions. Leaking of magnetic field into the shielding at high currents observed.
Jan-Feb 01 Moving collimator for calibration purposes designed and sent to production.
15 Feb 01 Beam Test successfully finished! See some of  the  results .
31 Jan 01 Rebuilted detector LSD Up (BPC South) tested. Tests proved, that it is working well.
22 Jan 01 Beam test at DESY II started with LSD Down (BPC North) in the beam
Jan 01 LSD Up rebuilt.
LSD = Luminosity Spectrometer Detector
Dec 00 Trigger counters for test beam produced and tested.
Nov-Dec 00 LED test of all the PMT's to be used in spectrometer detectors performed and gain curves extracted.
Sept 00 Wave Length Shifter scanning and production of correcting masks finished

Older Status Records


Date
Comments
3 Aug 00
BPCnorth added in lumiGeant.
25 Jul 00
BPCs Co60 analysis performed: Results.
20 Jul 00
Wavelength shifter scanning stand was setup. Scanning of the WLS for measurement of the attenuation length started.
18 Jul 00
32 PMTs have been tested in groups of 6, using a blue LED. For these tests 4 HV values were used (600,700,800,900V).
14 Jul 00
Wavelength shifters (19) were produced and aluminized.
12 Jul 00
High Voltage. We managed to set PMT high voltages using a serial line RS232 connection to the COM box. The COM box connects to 6 HV power supplies each of which feeds 6 PMT channels. We have not managed to use the mhvd "daemon" which is supposed to establish a connection between the COM box and to the outer world via a specific port on the LINUX host.
5 Jul 00
Radiation Damage: Calculations show that backscattered synchrotron radiation from the gCal filter siting just downstream the spectrometer will destroy the detectors. The solution to this problem is to shield the spectrometer with lead or W and move the whole gCal setup downstream by 2m. A ZEUS note is being prepared.
20 Jun 00
First version of the Spectrometer reconstruction software is designed based on existing BPC analysis software. The first energy and position reconstruction routines have been written. Tests are being performed with "mock" data from MC electron hits on the spectrometer.
15 Jun 00
LED circuits for the Lumi detectors: we are trying to build a prototype LED circuit which will be placed in the tunnel next to the detector and will test the gain stability. We would like to test the stability of the LED with temperature T. The reason is that the QE curve is T dependent. We need blue LED because of the plateau in the QE curve. We have 2 different circuits, one with a transistor switch and one using a thyristor but the pulse out of a PMT looks rather wide (30ns FWHM). When we use a yellow LED the pulse width gets as low as 15ns. It seems that these circuits are LED speed sensitive. Work in progress.
1 Jun 00
A temporary DAQ has been setup. We have an SGI IRIS/35 machine a VME communication card plugged in the back of it. Then, from the VME we go straight to a CAMAC crate on which we have a VME/CAMAC interface controller. We have succesfully used a software on the SGI machine to read out an ADC module.
Date
Mechanical 
Electronics
Magnet
Simulation/Analysis
Other
from 29/Nov/99 to 3/Dec/99
Proton beam pipe flanges upstream spectro shadow the small BPC module. Possible solution: use smaller flanges and move flange located at 104.7m. A first draft of the combined lumi electronics has been released. water cooling is adequate for magnet current: for 290A the power is 10.3 kW and the diff. pressure 8 bar (Calculation). It was determined that the minimum distance from IP that spectro can be placed is Z=104.5cm.  Support Structure design by a DESY engineer has started.
from 15/Dec/99 to 23/Dec/99
NOT NOT NOT BPC south ported to LumiGeant from MOZART. NOT
from 7/Feb/00 to 14/Feb/00
BPCsouth extracted from ZEUS. Transmission tests performed. Magnet order was placed. NOT BPCs was moved in Bld 67, Room 12 where Co60 tests will be performed.
from 14/Feb/00 to 29/Feb/00
NOT Transmission tests show a 50Hz noise of xxmV NOT NOT Co60 scans showed no significant radiation damage
from 4/1/00 to 4/20/00
NOT Transmission tests at Nevis: (Results). NOT NOT NOT
If you have comments or suggestions, email me at  helbich@mail.desy.de