=========================================================================== + THE SVEDBERG LABORATORY Proposal / Letter-of-Intent + + =========================================================================== Title of experiment: Single Event Upset test of the voltage limiter for the ATLAS SemiConductor Tracker ___________________________________________________________________________ Collaborator: Institute: Igor Mandic Jozef Stefan Institute, Ljubljana, Slovenia ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ Spokesperson for the collaboration: dr Igor Mandic ___________________________________________________________________________ Address: Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia ___________________________________________________________________________ Phone: Fax: Email: +386 1 4773535 +386 1 4257074 igor.mandic@ijs.si _____________________ ____________________ ____________________________ Requested beam time: Ion species Energy/nucleon Beam intensity Number of Charge state (MeV/A) (nA or 8-hour (Beam line) # particles/sec.) shifts p E>60 MeV 10^11/cm2 over 5x5 cm _______________ ___________________ ______________________ __________ _______________ ___________________ ______________________ __________ _______________ ___________________ ______________________ __________ _______________ ___________________ ______________________ __________ Time preference: August 2002 ___________________________________________________________________________ Earliest date the experiment could run: June 2002 ___________________________________________________________________________ What equipment, floor space etc at the experimental area is expected from TSL ? The components will be biased and controlled during irradiation. The length of the connection cables is not important. Very little space needed for power supply and readout electronics (i.e. 1 ordinary size table). ___________________________________________________________________________ ___________________________________________________________________________ . What electronics, data acquisition and other support is expected from TSL ? None ___________________________________________________________________________ ___________________________________________________________________________ Summary of the experiment (do not exceed this 20 lines space): Voltage limiter circuit has to be tested for Single event upsets before it could be installed into ATLAS detector at CERN. The circuit contains parts which could be permanently damaged by high energy hadron interactions. The damage of the limiter could lead to the loss of its function: guarding the readout electronics against overvoltage. It could also result in the failure of silicon detector module because of its interference with power supplies. The experiment would consist of placing limiter circuits into the high energy beam (E>60MeV) and periodically checking their performance while in the beam. Given the location of limiters in the ATLAS detector they have to be exposed to a fluence of ~10^11 hadrons/cm2 to qualify. ___________________________________________________________________________ Attach a description and scientific justification of the experiment providing the following information: I. Scientific justification a) What are you trying to learn ? b) What is the relation to theory ? c) Why is this experiment unique ? Electronics in the ATLAS detector on the Large Hadron Collider at CERN will be exposed to high doses of radiation. Every electronics circuit which will be used in the ATLAS detector has to be tested with respect to radiation hardness. The doses to which certain component has to be irradiated depend on its position in the detector. The radiation field in the ATLAS detector will contain also high energy hadrons. It is well known that interactions of energetic hadrons inside integrated circuit can trigger processes which may destroy the device. Since the ATLAS SCT voltage limiter contains such circuits (like shunt regulator TL431) it has to be exposed to high energy beam in order to estimate its sensitivity to such effects. II. Details of the experiment a) Description of apparatus. b) What is the status of the apparatus ? c) What targets will be used and who will supply them ? d) What parameters are to be measured and how ? e) Estimates of solid angle, counting rate etc. and the assumptions used to make these estimates. f) Details of the determination of the required beam-time. g) How will the analysis be performed and where ? Four voltage limiters on a PCB will be exposed to the beam. The bias connections will simulate ATLAS conditions. A resistor load will be connected over the cables with appropriate resistance (together with appropriate capacitances) to the power supply to simulate the readout electronics. Periodically the resistance of this load will be steeply increased which will cause voltage increase on this load due to the decreased voltage drop on the cables. This voltage increase has to be controlled by voltage limiter. Dimension of one limiter is about 2x3 cm2 and four of them should be irradiated. Fluence should be 10^11 p/cm2 and should be reached not faster than in one hour in order to perform several functionality tests during irradiation. Schematics of the experiment can be seen in figure at the address http://www-f9.ijs.si/~mandic/limiter/vlim_sch.pdf The current drop through the load (simulating module) will be caused by opening the ST1 switch. The maximum voltage (after turning the switch off) on the module U = Vmod-Vmodr will be measured using a sample and hold circuit. If the limiter is functioning properly voltage U should not exceed value set by the limiter. III.Background a) Status of data taken in previous studies. b) What makes the TSL facilities suitable for the experiment ? c) Other considerations relevant to the review of the proposal by PAC. No tests with respect to SEU have been done on this circuit. The circuit has been irradiated with reactor neutrons (to 6e11 n/cm2 1MeV NIEL equivalent) and ionisation dose (35krad) and has showed sufficient radiation hardness. TSL providing a beam of protons with well defined energy (larger than 60MeV) is an ideal tool for SEU tests. =========================================================================== Send this info to: Postal Address: Phone: WWW: http://tsl.uu.se TSL, Hans Calen Box 533 Nat 018 4712500 Fax: Email: S-751 21 Uppsala Int +46 18 4712500 Nat 018 4713833 CALEN@TSL.UU.SE Sweden Dir 018 4713846 Int +46 184713833